Rambling Outside the Box

The “Science” behind “Bonking”

2011-03-31T15:54:00.000-07:00

It has long been “common knowledge” that endurance exercise is fuel-limited. This is most familiar to general populations as a commonly observed limitation on foot races that says that you will run out of energy, “hit the wall,” or “bonk” at around 20 miles. For common race distances, the effect is most frequently observed in the marathon (26.2 miles). The standard explanation is that you can only store a limited amount of carbohydrate fuel in the form of muscle and liver glycogen, and that you will bonk when the supplies run out. Management of the “problem” is variously accomplished by “carb-loading” before the race to super-fill (“super-compensate”) the glycogen stores, and by various refueling strategies during the race (which support a large industry that provides special drinks, gels, bars, and the like).

At the same time, there is a growing body of evidence that there is no reason to depend on stored carbohydrate fuel which is limited in quantity if you can mobilize your fat stores as a source of fuel. The problem seems to be that anyone who is accustomed (adapted) to eating a high-carbohydrate diet tends to preferentially burn carbohydrates as fuel and does not utilize the energy available from fat in a way that spares carbohydrate use during endurance exercise. These are the so-called “sugar burners” as compared to “fat burners.”

There are a few possible strategies to enhance fat burning. The most commonly discussed strategy is to train at slower, more aerobic paces, to train the body to optimize using fat as fuel. This approach was discussed by Alan Couzens. Although carbohydrate was also restricted, the main emphasis was on low intensity training, with pretty amazing results from the combined approach.

A second strategy, perhaps even simpler, is to change to a low-carbohydrate diet. Maintaining glycogen supplies in a partially depleted state encourages the development of aerobic apparatus via the action of AMP Kinase (increased mitochondria and associated fat burning enzymes such as carnitine palmitoyltransferase, necessary to help transport fatty acids across the mitochondrial membrane). People with deficiencies of carnitine palmitoyltransferase are unable to utilize fat for fuel efficiently, and can even suffer damaged muscles and rhabdomyelosis resulting in kidney failure. There is also evidence that people suffering from obesity and diabetes may have impaired mitochondrial function, which inhibits their fat burning and at least partially explains the origins of their condition. Similarly, a deficiency of carnitine can result in impaired mitochondrial function and even lead to symptoms of metabolic syndrome.

There is an adaptation period of a few weeks to lowering carbohydrate intake during which the appropriate metabolic pathways and aerobic enzymes and cofactors are up-regulated to better utilize fat as a substrate, allowing blood glucose levels during exercise to be more easily maintained. As Alan Couzens explains, lower carb intake should result in a 20% increase in fat burning in a few weeks. Numerous scientific studies bear this out. A recent study, for example, concludes that a high fat diet increased the rate of whole-body and muscle fat oxidation while reducing the rate of muscle glycogenolysis during submaximal exercise, even after restoring high carbohydrate intake. In this study, a high fat diet was followed for up to two weeks (which we know is just long enough to see significant adaptation), during which usual training was followed. A high carbohydrate diet was restored for the last few days along with a taper before racing. The athletes were able to maintain the increased fat oxidation even after reinstating high carbohydrate intake.

There is at least one supplement (Vespa) which is alleged to improve fat-burning during exercise. There is also some evidence that, all else being equal, the athlete that has the most efficient fat-burning ability can consistently beat the athlete with the higher raw power output (higher VO_{2 max}) in endurance competition.

An article in Running Times last year discussed the strategy of carb cutting to increase endurance, though the article suggests mainly forgoing carb supplementation on training runs, not going low carb in the training diet. The Ethiopian runners again are cited as evidence that a high carb diet is necessary to fuel runs, and there is speculation that they are somehow training themselves not to use glycogen as the predominant fuel by not consuming carbs while actually training. This conclusion seems unlikely to us, since it is well known that exercise causes an increase in blood sugar (due to action of epinephrine and glucagon), effectively mimicking the result of taking in supplemental carbohydrate while exercising. A marathoner does not “hit the wall” until they have run ~20 miles at race pace anyway, a condition not likely encountered during routine training runs for most of us.

Despite all that is known about “the wall,” people persist in believing that a high carbohydrate diet is necessary if you hope to be a good runner. A high carbohydrate diet may work well for Ethiopian runners, who are known for running prodigious mileage and training three times per day. At this training intensity, we seriously doubt their glycogen stores are ever completely full, and they may effectively be training in a perpetually glycogen depleted state, which would upregulate the same enzyme systems that occurs in the low carbohydrate condition. Perhaps what they are mainly training is the rapid replenishment of glycogen stores. However, for most of us amateur or older runners, we’re only fooling ourselves if we think we need to fuel exercise with a high carb diet. David does quite well on very minimal carbs (less than 50 g/day), while Cynthia prefers closer to 100 g/day. Since we generally only run once per day and even then usually less than 10 miles, there is no reason to consume any more carbs to fuel our exercise habits.

David has been a low-carb runner for more than two years now, keeping carbohydrate consumption low before, during, and after endurance exercise. While he won’t brag about his speed and has no plans to challenge any course records, he consistently finds that he has even energy levels and rapid post-event recovery with minimal muscle aches and pains. Fat fueling works for him! However, until very recently, while he refueled less often than is typical, he did routinely refuel using protein and fat for any event of more than 3–4 hours.

He was prompted to revisit the issue when he heard about a recent study (“Metabolic Factors Limiting Performance in Marathon Runners”) by Ben Rapoport when he had his fifteen minutes of fame on NPR in October 2010. Ben was attempting to model bonking in the context of marathon runners. David subsequently exchanged e-mail with Ben whose initial reaction was to interpret David’s personal experience as simply confirming Ben’s model, arguing that fat-fueling works, and that you don’t bonk as long as you run sufficiently slowly. David pointed out some flaws in Ben’s interpretation of the scientific data he analyzed and challenged him to define a performance that David might personally be able to achieve that he might consider sufficient to disprove his model, but he never responded to the challenge. We summarize here both a couple of the criticisms of Ben’s model and analysis and some more recent personal experience and experiments.

A key part of the experimental data that Ben used in building his model came from Romijn AJ, Coyle EF, Sidossis LS, Gastaldelli A, Horowitz JF, et al. (1993) “Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration,” Am J Physiol 265: E380–E391. That paper shows (in Fig. 8) the relative amount of particular substrates which are used in short-term exercise at three different intensities. The subject’s dietary habits were not identified, and any changes that might take place over more than a few minutes were ignored. The data show that more intense efforts use primarily muscle glycogen as fuel. They do not show the pathways that feed the muscle glycogen. Glycogen and glucose are rapidly interconverted, and over longer periods of exercise, new supplies of glucose are made by the liver. The liver, in turn, is capable of using any available fuel source via gluconeogenesis to keep blood glucose levels up. These fuel sources include ingested carbohydrates, protein, and fat as well as lactate, glycerol from liver and adipose tissue fat stores, and even body protein stores such as in muscle tissue. Which source predominates depends on availability. Some of the necessary up- and down-regulation of different metabolic pathways can take place on a short time scale to respond to instantaneous demand for fuel from the muscles and other bodily functions. However, there are also some key adjustments that respond more to average demand and supply to deal with changing diet, exercise demand, starvation, and the like, and these are events that tend to have time constants measured in days or weeks, not minutes or hours. The adaptation processes may be numerous and complex (or at least, we fully admit that we don’t understand all of them) and likely include adaptations in the skeletal muscles as well as in the liver. However, we think it is clear that the data extracted from Romijn do not actually show the underlying consumed fuel source for various levels of endurance exercise, and the data cannot reasonably be extrapolated to model and predict bonking.

One factor which Ben cites in favor of the importance of carbohydrate and fueling is the relative stoichiometry of oxygen consumption for each substrate. He states that carbohydrate oxidation typically generates approximately 120 kcal per mole of respired oxygen, whereas fatty acid oxidation typically generates only approximately 100 kcal per mole of oxygen. We would argue that this, while probably correct, is irrelevant in that the difference is relatively small, and the availability of oxygen is never a limiting factor at a typical aerobic marathon pace. There is always an excess of oxygen available. In any case, regardless of the underlying fuel used to generate blood glucose/glycogen, the immediate muscle activity (except for very short term bursts of power) is fueled by glucose.

Notwithstanding the possible flaws, Ben’s model does make predictions as to whether one is likely to bonk in a marathon. In particular, he has provided a calculator for the marathon. Putting in the best estimates David has for his personal situation, the calculator predicts that he should not bonk for finishing times over about 3 hrs. Since he can only sustain a 3-hour marathon pace for about 1 mile or so, he may never be able to really challenge the model experimentally using himself as a test subject.

However, David was inspired to test his need for refueling during running, and now has a significant number of test results that, if not sufficient to explicitly challenge Ben’s model, are at least startling to many people. For some time now, David routinely runs training runs of up to 4–5 hrs without refueling (water alone). This is still true when he runs with his son at faster speeds who typically chooses to refuel using at least a couple of energy bars or gels. David first pushed the envelope a bit on what was supposed to be a planned 18-mile run that stretched to about 26 miles when the route was blocked by an impassable rain-swollen river crossing. That run extended over about 7 hours including some significant rest breaks, so it was not at a strenuous pace, although it did include some significant elevation change. David consumed only water. The next experience was a 50K (31-mile), mostly flat run, again at a very modest pace, finishing in 6:50, again on water alone. Two weeks later, he completed a much more strenuous 50K on rough rocky trails with about 6000 ft of elevation gain (and loss) in 7:28 on water alone. In all three of these runs, David started with a breakfast of a two-egg cheese omelet and bacon about two hours beforehand. He felt some minor hunger around normal lunch time, but otherwise did not experience any significant fluctuations in energy level, and he certainly did not bonk. His overall weight was down about 3–4 lbs at the end of the day compared to the beginning, but looking at beginning-of-day weights across several days, any weight change was pretty much lost in the noise. Of course, it only takes about a pound of fat to fuel a 50K run, anyway. Another week later David ran yet another moderately hilly 50K event which was slower (8:04) due to snowy trail conditions. Due to a late start (10 am), he chose to eat a little at around the 6-hour mark, mostly because it was a long time since breakfast. However, the ability to do three 50K runs in four weekends, certainly confirms that post-event recovery was rapid.

So what’s the take-away message from all this? It’s interesting to compare our reaction and the experiments that David decided to try to others. Greg Crowther also blogged on Ben’s article. Greg’s big concern was inter- and intra-personal variability, and he questioned the validity of extrapolating from some sort of average measurement of performance to the needs of one individual on one particular day. He didn’t ask (as we did) if too many runners are needlessly afraid of bonking but rather, “if ingesting extra carbohydrates before and during a marathon might help you avoid ‘hitting the wall,’ why wouldn’t you do it? Especially after investing all of that time and effort in training, traveling to the race, etc.?” Hey, we’ll even go further: if ingesting fuel (whether carbohydrate, protein, or fat) during a race might help you maintain a faster pace for whatever reason and for whatever limited portion of the race, even it’s just a placebo effect (or tricking your Central Governor), then by all means go for it! But we also stand by our basic conclusions that (1) carbohydrates are simply not necessary before, during, or after endurance exercise, (2) they’re probably not even particularly beneficial, at least if you are suitably adapted to efficient fat-burning (and may be harmful to your long-term health) and not logging very high miles at high intensity, and (3) unless you’re able and motivated to run, say, an entire marathon at a high percentage of your VO_{2 max}, consuming much of any food immediately before, during, or after the event is entirely optional. Moreover, there may be some benefit to having the stomach completely empty while racing, in order to avoid stomach upset, intestinal discomfort/diarrhea or nausea when running at high intensity. (David does continue to believe in significant protein consumption sometime in the 12 hours or so following strenuous exercise as an aid to muscle repair and recovery, but the timing of even that refueling does not appear to be nearly as critical as some authors suggest.) David will probably resume modest consumption of fat and protein on longer events, just because he’s not big on skipping meals entirely, anyway, but it’s reassuring to know that he can easily keep going without any fuel if for any reason he needs to.

Rio Del Lago 100 Mile—A DNF

2010-10-15T16:11:00.000-07:00

If you’ve read my previous entry about all my injuries and travails in the past year, you might think it a silly thing to sign up for a 100-miler, and you’d probably be right. But life is short, and sometimes you just have to go for something, even if wiser heads would counsel you otherwise. This attempt was not successful, and not even all that impressive as a first attempt, but has lots of lessons that might be of interest to some.

Prologue
I remember running a series of marathons in the 1980s and hearing about the first running of Western States 100. I was awe-inspired at the difficulty and epic-ness of such a journey and fantasized about someday trying it myself. Life got in the way of such aspirations, but ever since, it’s been in the back of my mind that I wanted to do a 100-miler. I’m now also interested in exercise physiology, and diet and exercise effects on health, and am intrigued by how the body manages energy, so experiencing the highs and lows of energy in ultra events is fascinating to me. So kind of on the spur of the moment, I decided to give Rio del Lago a try.

Now tackling a 100-miler for someone like me is no easy matter. In addition to having a bum and finicky foot, I’m not particularly fast, robust, or tolerant of heat, and my feet get easily blistered (OK, I’m old, frail, slow and whiny, especially if it’s over 70º F). I consulted with Don and Gillian http://www.zombierunner.com/ about strategy and was told to 1) get lots of sleep prior to the race, 2) be comfortable with night running, 3) keep the pace down, walking the hills, and 4) resolve not to give up. Don warned me it would be warm, but I was still glowing from the unseasonable cold front that had just gone through a few days prior. The pace chart indicated that the paces necessary to complete the race are not even that fast—for more than half the race, an 18-minute pace is good enough to make the cutoff times. I felt pretty confident I could manage those factors and that pace and decided to go for it. David agreed to be my crew and pacer if needed, even though his Achilles was not really up to running long distances, but he felt that with the pace I’d be keeping late in the race, it would likely be easy enough that he could pace me without aggravating his injury.

Since I signed up on the last possible day (Thursday) before the race, I didn’t have a lot of time for the reality to sink into my head. As a consequence, Thursday night I barely slept—I dutifully lay there inviting sleep, but my mind had other ideas, namely processing the shock of actually trying to “run” 100 miles (Ok, we all know it’s not all running, but lots of hiking or walking too). This insomnia was unusual and was the first strategic error of many. We drove up on Friday afternoon after frantically trying (and failing) to find our night-running lights, arriving late for the check-in, and then had to go shopping for flashlights. I was such a wreck that my blood pressure and heart rate were abnormally high at the check-in. Of course they were—I was about to do a really challenging and stupid thing, I was terrified! (But at least my valves checked out healthy.) We found several cheap LED flashlights that seemed suitable for the night running portion in a hardware store and proceeded to dinner and finish preparations for the morrow’s race. Dinner was at Denny’s (I had tilapia and mashed potatoes—that and some yogurt with fruit and granola was the extent of my carb loading on Friday). We got my breakfast for the next morning (eggs, sausage, hash-browns and pancakes) as take-out so we would be all set to go.
After dinner, it was time for a shower and foot preparations. I opted for kinesio tape around the balls and heels of each foot and a couple of toes each (but no tincture of benzoin). The middle toe on my left foot seems to blister without fail of late and I was most worried about it, so I taped it and the adjoining one for good measure, and did the same for the right foot. We were in bed by 9:30 and I fell asleep quickly, being already sleep deprived, only to wake up at midnight unable to fall asleep again. Not only could I not sleep, I began to get a nagging headache that I could not ignore. By 4 AM I started in on ibuprofen, and by 5 AM when I was supposed to be eating my hearty breakfast, I was nauseous and unable to eat more than a couple of bites of egg and hashbrowns. This was unpleasant, but not necessarily terrible, since I am used to running fasted or having eaten little. I would have to make do with the Gu in my bottle for fuel (and a few gels) until the aid stations.

A blur of one of the fast runners

The Race
Standing around before the start, I said hello to Stacey and Misty (they looked so cute in their race outfits) and looked around for other people I knew. But conversation would have to wait because in moments we were out the door with our flashlights in the pre-dawn gloom. The first section was nice and cool, and easy with rolling hills on wide trails. I tried to walk the hills, but occasionally ran them anyway since they were shallow and I was way too excited to slow down. It began to warm up as soon as the sun peeked over the other side of Folsom Lake, and I realized then that it was indeed going to be HOT, not just warm. My T-shirt came off and I decided to pick up the pace a little to get as far as possible before being reduced to melting slug pace. This worked for the first few miles, and I ran with a few other runners, trying to navigate the poorly marked section (someone had been removing ribbons). The Twin Rocks section proved difficult—stepping up and over boulders and roots, then back down, never too much elevation change, but tricky footing nonetheless. I ran with Tracy Youngstedt for a while and commented that I knew I was supposed to get through the first third of the race without doing anything stupid (according to Olga), this after nearly doing a face plant from kicking a root. Finally the Twin Rocks section was finished and I finally saw David for the first time at Rattlesnake Bar (mile 11.9). He offered me breakfast, and I took the rest of the eggs and hash-browns in a cup, and attempted to eat them during walking breaks (of course after dropping the cup and spilling the food a couple of times, didn’t manage to eat all that much). On past the power plant and toward Cardiac, all seemed well until the trail began to really heat up in the strengthening sun. At one point I came across a stream and just stared at it incredulous—coolness. I untied by T-shirt, dunked it in the water and draped it across my shoulders—instant relief! At another creek crossing, I refreshed the wetting and so was kept somewhat cool until reaching the aid station at the foot of Cardiac (where ice and Coke was provided). It was now full blown HOT and all I could do was trudge forward toward the flume trail, chewing on bits of ice. The flume provided more shirt wetting and relief, and I managed to jog a bit now and then toward Maidu and then Auburn Dam Overlook. At Maidu (mile 21.2), the aid station volunteer gave me a juicy PB & J sandwich, of which I again only managed to eat half (though it was delicious).

Maidu aid station and the flume trail

I reached Auburn Dam Overlook (mile 22.7) well within the cutoff time (well, 40 minutes to spare), got weighed and was maintaining weight ok, so presumably hydration was ok. David handed me V8 juice in my water bottle, well diluted with ice. I took coke with ice as well, wetted my T shirt again, and proceeded down what I expected to be an easy bit of downhill to No Hands Bridge aid station. Unfortunately, this stretch of trail was not all downhill, not easy, and HOT. There are numerous uphills which appear as innocent little jiggles on the course profile. I was amazed to see both Jean Pommier and Sean Lang already returning from Cool at this stage! They looked so light and fresh trotting up the hill to Auburn Dam Overlook. I set my Garmin to re-charging on this section and so could not see how long it was taking, but it seemed to take forever even though it was net downhill (800 feet).

trotting towards Auburn Dam Overlook

I finally dragged myself into No-Hands Bridge aid station (mile 26.7), barely able to muster a trot on level ground over the bridge in the oppressive heat. One fellow runner sitting at the aid station looked to be suffering from heat exhaustion, as he was trembling and pale and limp. The sympathetic volunteers loaded me up with ice—in my hat, bra and bandana—for the long climb up K2. I got more iced V8 from David and took some grilled cheese sandwich pieces (which I again did not manage to eat). I was prepared for this steep climb and its numerous false summits, and it wasn’t too bad. There was some shade at least and my ice kept me cool enough to keep moving, but slowly. I did pass my first “conquest” at this stage—a man who had been nauseous for the last ten miles, he said. He described himself as an “urban polar bear” and bemoaned the fierce heat radiating up from the trail (if only the clouds from the few days prior had remained), with which I agreed wholeheartedly. I was still moving ok, though mostly just at a walk towards Cool, and passed S Baboo on his return from Cool, all smiling and making it look easy. At this point, my stomach too was beginning to feel funny. There was a suspicious pain and when I pushed on it I realized that my entire belly was distended with liquid—I wasn’t processing fluids anymore! Trouble seemed to be brewing.

unknown runner coming across No Hands Bridge

Finally at Cool (mile 29.8), I switched to ice water only and sucked it down like a fiend. I’ve never experienced thirst like that, and could not get enough water. I also got this idea in my head that I might be getting too much potassium from the V8 juice and was worried about developing a heart arrhythmia (don’t know where this idea came from but it was probably wrong). I tried again to eat some solid foods when David gave me a cup full of “beef bowl” (beef, broth and rice that we brought with us) which I badly needed for fuel. I left this aid station nursing my cup of coke and ice (mostly ice), then drinking ice water. There was very little shade, and at one point I just sat down on the trail in the shade of a tree for a moment. I believed I had plenty of time and just needed to get through the loop without mishap, and hopefully things would be cooling off by the time I had to head back to the hot canyon. There was one other runner that I played leap frog with here. He got ahead of me after the aid station, because he ran while I walked (lazy me), then when I was getting desperate for more water, I ran and passed him again. Finally refilled with ice water at the Knickerbocker Hill aid station (mile 35.3), I ran briefly on the 1.5 mile road section, but just couldn’t bring myself to keep running, even though there was a nice breeze by now and it was plainly cooling off. I practiced a power walk instead and was pleased that it wasn’t too bad.

Refilling with food, ice and water at Cool again (mile 36.9), I left at a leisurely pace crunching on ice, drinking coke and slurping a small cup of beef bowl (only had two hands or I’d have carried more food!), then upon reaching the downhill, trotted along as expeditiously as possible, watching for the trail markers, afraid I would miss the turn like one runner I saw coming the wrong direction down K2. This section was relatively fast and easy, but upon reaching the No-Hands Bridge aid station (mile 40.4) realized that I had run out of buffer time and was going to have to run my tail off back up to Auburn Dam Overlook, 4 miles with an 800 foot climb in a little over an hour! While this section was my least favorite on the way out, it became my favorite on the return trip. Even though it was a long climb, it was broken by brief downhill segments (uphill on the way out), and much of it was of a runnable grade, plus it was cooling off by now. I pulled into Auburn Dam Overlook aid station (mile 44.3) as the volunteer was yelling a three minute warning at me, quickly weighed myself (only 2 pounds down), then had to leave immediately for Maidu. I followed the flume trail feeling good, jogging and passing a couple of other runners, then met David again for another refill on food at Maidu (mile 45.8). This time he added coconut milk with chicken broth to my beef/rice bowl, and the feeling of actual calories going down my throat was amazing. To this point (45 miles) I had eaten a half PB&J sandwich, 3 gels, a few bites of egg leftover from breakfast, 2 bites of grilled cheese, a couple bottles of Gu, 3 bottles of V8 juice, and several small cups of Coke, and I had been on my feet for 13 hours! I guess I was starting to get tired and hungry. David offered to pace me, but I told him I felt surprisingly good and declined his offer (this would turn out to be a mistake). He asked me if I wanted to take a dry T-shirt and I said I was still hot, but at least I didn’t need to wet the T-shirt anymore!

View of American River Canyon

Off along the flume trail again, I turned down the wrong trail (getting behind again) and had to backtrack. It was now becoming dark and the flashlights were necessary, and it was really hard to see the marking ribbons. Going down Cardiac in the dark was also much, much harder than the climb up had been. I couldn’t see far enough ahead on the twisting rooty trail to have any confidence in my footing, so inched down slowly like an old lady (which I guess I am!). There were numerous trail junctions that I hadn’t even noticed on the way up, and each required careful searching for ribbons, which took additional time. At the bottom, all I wanted was to sit and doze for a few minutes as the effects of the sleep deprivation suddenly hit me. But when I got there, the trail sweepers were waiting for me (last again!), and I had to keep moving. I tried to keep the pace up, jogging along occasionally, but the blisters on my feet, which until now had not really been much of a factor, suddenly became noticeable. I was trying to jog along on this overgrown trail, which I could see only poorly with my ghostly LED illumination, when I stumbled on a few rocks and several blisters tore open at once on my right foot. The pain was excruciating, and I suddenly realized for the first time in the whole race that I might not be able to finish, might not want to finish. The pain slowly faded, but now I was afraid of the slightest misstep setting off more blister pain. My jogging became more intermittent. Still, I managed to pass a couple of other runners and tried to keep my pace up, but this section seemed interminable, even though I had been looking forward to it as one of the more runnable sections from before. Finally after passing the power plant again, I encountered David coming in from Rattlesnake bar AS to find me. I had lost track of time, because my Garmin power had run out again and since I neglected to charge it again, it shut off. I didn’t realize it until he told me, but I was too far behind schedule and would not be able to make the cutoff time at Rattlesnake Bar (mile 55) and continue past the AS to finish the race.

Afterwards
I wasn’t too disappointed to have to quit because exhaustion and pain have a way of changing one’s priorities. We left Rattlesnake Bar aid station and returned to Cavitt School for some food (all they had that seemed remotely appetizing was watermelon) and a real bathroom (I was tired of peeing in the bushes). Then David just wanted to get us home. The drive home was uneventful and I slept pretty hard. Upon arriving home, I needed to use the bathroom as soon as I got out of the car, and discovered what exploding diarrhea was all about (just in time to the bathroom)! I don’t know what caused the diarrhea—whether it was a side effect of heat exhaustion and dehydration or a sign that my stomach and intestines just couldn’t absorb fluids as fast as I shoved them in. Perhaps the fiber and minerals in the V8 juice were the problem. A comment from one of the AS volunteers seemed to presage the event, as she pointed out that tomato juice gives her diarrhea. Finally home and cleaned up a bit at 3 AM, I had to eat some real food and opted for a large chicken breast poached in the rest of the coconut milk and chicken broth remaining from our supplies. It was delicious and nourishing and I finally slept, with my burning feet on icepacks.

The next morning, my weight was down a full pound and a half (it was down a pound before eating and drinking more before sleep). The real problem was my blistered foot. Only one foot was in a bad way, though I had taped them both the same. It was hot and inflamed and I finally resorted to just soaking both feet in cool water with a little salt and ice added—for TWO days! The blisters were two layers of skin deep, which is more than I usually experience. The plantar fasciitis as expected was not particularly noticeable. I discovered I had chafing over much of my body, wherever I had neglected to put Vaseline. So I had odd scabs on much of my back from the chafing from the water bottle and clothing. Finally three days after the event, my weight had spiked up two pounds, before the compensatory fluid retention passed. Once my weight declined again, I had lost a full pound of body weight, presumably fat, which stayed off. (For some reason, I’ve continued to lose weight in the aftermath and am now down to 138, a new low since going “low carb.”) However, I don’t recommend running 50 or 100 miles just to lose weight!

Postmortem
I now understand the addictive quality of 100-mile races. The lower key pacing throughout (for us back-of-the-pack-ers at least) was just fun and low stress. I only felt I was close to running hard on one segment (making it back to Auburn Dam Overlook)—the rest was easy going (with heart rate at least 10 bpm below my usual race paces). Instead of a race, it felt like an epic adventure, or a trail party. I always think about Aragorn and company chasing after the Orcs and captured hobbits in ultra events. It always feels like a challenge and an adventure, 100-milers even more so. So even though it was much hotter than I hoped, I had a great time.

Running in the heat is still a huge weakness for me, and even though I’m a lot lighter than I used to be, that problem remains. See the Science of Sport posts for some interesting discussion of the effects of heat on performance. Basically, your brain controls how much muscle gets activated when exercising: it senses the heat accumulation and sets the pace accordingly so that your core temperature doesn’t exceed ~40 C (~102º F). Slender, lightweight people can cool themselves much more efficiently, and accumulate heat more slowly, and so can perform at a higher intensity in the heat than heavier people. I guess I’m still too well insulated to perform well in the heat! It shouldn’t have been a deciding factor in this race, however—if I had managed all the other factors better, I could have made all the cutoffs and finished despite the slower pace. Someone like David with a BMI of 25 still performs much better than me in the heat even though theoretically he should overheat more, but perhaps he has the advantage of so much additional muscle that he only needs to activate a fraction of his muscle fibers to keep a comfortable pace.

I was completely prepared to feel crappy at some point in the event, then to come back to life with the sunrise or coffee or something. I wasn’t prepared at all for how quickly my energy levels could go from “I feel surprisingly good” to “I just wanna take a nap.” Neither was my crew. Advice for crew/pacers out there: don’t listen to your runner when they tell you everything is great. They are in denial and a bad patch is inevitable. So do the thinking for your spaced-out runner and try to foresee what they will need before they fall in a hole.

Even though I only made it to 55 miles, it was much harder on me and especially my feet than any 50 mile race I’ve ever run.* I attribute this to the total “time on the feet” fatigue from the slow pace, the drain of heat on salt and energy stores, and the accumulated damage to the feet (blistering is much worse in the heat), not to mention the sleep debt before the race. It’s also possible that I had not eaten enough calories to keep my energy levels high, since I estimate I’d eaten at most 2230 calories during the whole day (less than half the calories burned). Some of that difficulty was due to extreme thirst during the hot hours of the day, when I craved water, pure cold water, and my stomach was having trouble processing the input as it was.

I am intrigued with the energy requirements of these events. I’m not advising anyone to eat as lightly as I do in ultras, but I wonder why we need all this food. I wonder if it’s not mostly just to trick the body into thinking all is well and to trigger reward systems in the brain (like the study that found that just swishing a sweet drink in your mouth, but not actually drinking it, can improve performance). For myself, I know that when I get hungry while running, which certainly happens, eating some small amount of food fixes the problem, but if I don’t eat, nausea will occur and will not be easy to fix once started. Salty or starchy foods, sodas, protein, even fatty foods such as smoked salmon, cheese or nuts—they all seem to help. But this is more to keep the stomach happy than to provide fueling (though I was once revived by a tamale). Not everyone needs huge amounts of calories to get through ultras, for example, Jean Pommier wrote an account of Skyline 50K where he basically ran on nothing but sports-drink and Vespa (which is supposed to enhance fat burning). But again, fast runners just aren’t out there that long, and perhaps that is an important factor in total energy needs in an event.

In my case, a confluence of factors (getting dark, poor visibility, anti-climax from enduring the hot part of the day, accumulated fatigue and pre-existing sleep debt, blisters) suddenly outweighed all the race enthusiasm and improved conditions that came with the cool of night. It would have been helpful to anticipate these energy level fluctuations. We actually had caffeine pills and energy drinks, but elected to save them for later. Unfortunately, they were needed far sooner than expected. I can also say that night-running in a 100-mile race is not like night-running on familiar trails close to home. The dark makes everything more difficult—finding things that you need (especially if you drop something), keeping track of time, seeing far enough ahead to plan running segments and walking breaks, finding course markers.

I recommend this race to anyone contemplating running a 100-miler. The course is excellent, and the volunteers were amazing—experienced runners themselves, they were helpful and truly wanted runners to succeed. Unlike some races where cutoff times are rigidly enforced, in Rio, they are willing to bend them a little if they think it will help runners succeed. However, they could have improved the race by making sure enough trail markers were present, and that glow lights or reflective/phosphoresecent markers were used on the sections run at night, but if you’re not as slow as me or as slowed down by the heat, this problem could be avoided (the wider trails past Cavitt School would have obviated some of this problem too). On the other hand, if you struggle with heat as I do, perhaps you should wait to run this one on a cloudy day.

Gear
Drymax socks, Montrail Continental Divides, GoLite running shirt and skirt, Kinesiotape, hat, saltstick caps, sunscreen, bandana, ankle braces, Garmin 405, USB battery and charging cable.

What worked:
1. Ice in the hat and clothing cavities really helped in the heat- it offset some of the blast radiating off the sunburnt trails, though my legs and feet were always hot.
2. V8 juice really hit the spot, but perhaps less of it would have been better or I should have waited until later
3. Lubing all moving/touching parts
4. Eating food (most anything works for me) to keep the stomach from getting touchy and queasy. The beef with broth and rice went down well and kept the stomach demons at bay. Liquid calories (Gu) and caffeine (Coke) went down well too (though I don’t advocate for their healthfulness—still fructose intake in the context of exercise and low glycogen reserves is likely to rapidly replenish liver glycogen, so maybe in this limited context, fructose is ok).
5. USB battery successfully charged Garmin 405 on the run, and it continued to take data
6. Except for blisters, I didn’t fall down or get injured (I had sore leg and abdominal muscles a couple days later, but nothing extraordinary). I used about 1 Ibuprofen and 1 saltstick cap per hour, especially after 20 miles.
7. I was successful at not wearing myself out on the initial faster portions of trail or early climbs. I was aiming for an overall 12 minute pace on the “flat and easy” portion up to Cardiac at mile ~20, but this section turned out to be anything but flat and easy and my pace was more like 13–16 min/mile, which was still well within the pace estimated by the pace charts. More walking than running in the heat of the day was good enough to keep to the necessary pace.
8. My crew was excellent, attentive and supportive (Thanks David!).

What didn’t work:
1. My taping job sucked, at least on one foot.
2. My brain—I got serious brain fog once it got dark and the accumulated fatigue and sleep debt hit. I couldn’t seem to think straight or solve problems.
3. Signing up late and going into a panic, getting sleep deprived more than usual.
4. I didn’t leave enough time for any deviation from the plan. You need to keep a bigger buffer of time for shoe changes or brief naps etc. even if it seems you have plenty of time, because it can evaporate quickly on you. I should have pushed harder on the loop at Cool and not just waited until the downhills or the evening to do more running than walking.
5. On paper it may appear to be an “easy” 100-miler, but it was (and is often) too HOT to be easy for the vast majority of people. In my case I managed the heat well enough not to get heat exhaustion, but couldn’t quite muster the energy to move as fast as I wanted to.
6. Inadequate night-time lighting. My 60 lumen LED emitted a ghostly diffuse light that provided very poor contrast and texture, making it difficult to estimate distances and surfaces and slowed me down even further. (I had a second better light but was too spaced to think of using it.)
7. Apparently I had some issues with my intestines not absorbing fluids, though I don’t know whether it was due to fiber in the V8 juice or the heat and dehydration itself impeding intestinal absorption. If I had continued on the trail, it could have become very unpleasant.
8. Going it alone when I was getting tired. I should have accepted the aid of my pacer who could have helped me find the trail and keep to the required pace.
9. Not lubing enough skin surfaces—some nasty abrasions and chafing resulted.

* Well, Firetrails this year beat me up pretty bad too.

The year of running injuriously

2010-09-22T15:22:00.000-07:00

Cynthia’s Experience

Ok, silly title, but apt, as you will see. As of late summer of 2009, after running the SF Marathon and wondering why I was so much slower than expected, I intended to increase my mileage and see if I couldn’t improve my running ability. That did not happen as planned obviously, or I would have been happily blogging about my triumphs attempts. For running friends wondering what has happened, here is the sad story of the last year in running.

May 2009 at Quicksilver 50K, I landed badly while jumping across a creek—the embankment was at a steep angle, which I failed to notice until midair. Afterwards, I had swelling and pain in that foot off and on for a couple of months. It never hurt particularly badly and I mostly ignored it, continuing to run on it, even completing Diablo 50K a month later without problem, with my foot at least. Anyone who has done an event at Mt. Diablo knows it will take a lot out of you one way or another. I mentioned this in blog entries in June 2009 and July 2009. I thought I was babying it enough by taking it easy and mostly running uphill, where the foot falls are softer and more controlled. It did feel like there was some structural weakness for a couple of months when I’d try standing on the ball of that foot with my full body weight, but I figured it would pass. Mostly I just congratulated myself on having good recuperative powers, and continued to run as much as I pleased, and never bothered to get any x-ray or medical opinion.

In summer 2009 while training for the SF Marathon, I ran more track workouts and harder road runs, not the varied and softer surfaces of trails. A glimmer of foot pain began, but remained sporadic and mysterious until by August, after the marathon when I got the bright idea to up my mileage, I developed the dreaded plantar fasciitis. I scoured the web for information on treating and training with PF. One of the more useful references I found is from the Sports Medicine Institute, complete with physical therapy recommendations. My symptoms matched those of textbook PF, and I began to treat it as recommended—icing, using arch supports, keeping the fascia stretched, reduced running, using ibuprofen, etc.

When September came around, it was time for Steven’s Creek 50K. This is another charming local race on trails that we often train on, put on by Steve Patt of Steven’s Creek Software, with proceeds to benefit the Audubon Society. In 2008, the first year I ran this event and only my second 50K, I had such a poor time that I was determined to come back and vindicate myself, hurt foot or no. In 2009, the weather was cooperative, cool and even a few sprinkles, and I managed to improve my time by over 2 hours even with the injury! This tells you how terrible I am in the heat. I found myself running slower and scouring the trail ahead for the softest surfaces to run on, but my foot seemed all right afterwards.

So without too much fear, I signed up for a second running of Dick Collins Firetrails 50 Mile. I thought I would be faster since I was fresh from marathon training and significant hillwork and was lighter compared to 2008. Instead, I was slower by 40 minutes (almost a minute per mile slower!). It turned out to be a truly miserable experience, with me fantasizing about using crutches for much of the race, wincing down the long descent to the turnaround and just generally having the motivation sucked out of me by pain. I vowed not to run any other races until it didn’t hurt so much to run.

For the rest of the Fall/early 2010, I was reduced to easy running/rigorous icing, stretching and physical therapy. I could run, but not fast, and not far (nothing new really, but I didn’t enjoy being even slower than usual). There was almost no pain running uphill—this is of course without any kind of energetic bounding, which would likely negate the pain-free aspects. But of course, there is the downhill part to every run, where I would cringe and whimper my way back down. The strange part is how much more it hurt after running than before or during, and more than in the mornings when it is supposed to hurt the most (“first step” pain). On bad days, the arch and entire heel blazed with heat from the resulting inflammation (icing certainly helps with that), and even tingling or buzzing sensations from nerve irritation and entrapment. I also noticed occasional toe numbness and neuroma-like symptoms, but it seemed to be specific to going uphill, and was helped by walking on rocks that would put the pressure on the arch and not the ball of the foot.

During this time, I compared my feet and realized that my injured foot was now noticeably longer than the right (before, the right was larger), and the right calf musculature was better developed. Whatever injury I had sustained caused the foot structure to attempt to adapt and compensate for the weakness. The bone structure in the arch is now noticeably thicker as well, and presumably is stronger. This picture shows the two feet aligned heel to heel (excuse the post-Rio blisters). The plantar fascia can be easily seen when the toes are stretched back, revealing the tautness of the fascia. Unfortunately, the left fascia is still much tauter than the right due to the relative fast growth of the foot. The tautness can be more readily felt than seen, and the right is springier, with more give to it, than the left. Whenever I strain the fascia, such as landing on the toes going downstairs, skipping, running fast, I can feel it yanking on the calcaneus as if it was trying to pull free. In the acute phase, it felt like an ice pick or broken glass in my heel. Now it is merely a dull but persistent pain.

During January, we cut back running in favor of some weight and cross training, but ran the Fremont Fatass 50K anyway. This is a local event organized by Catra Corbett and Mike Palmer, a friendly (mostly) flat run on bike trails between Quarry Lakes and Coyote Hills. My foot wasn’t too bad on the trail part, though the pavement portions were painful. Then we ran the Second Saratoga Fatass 50K in February (where we got lost and only did a marathon) and Adam Blum’s Overgrown Fatass Marathon, where I was feeling better (and won the women’s event—Yea me! I think there were only two of us!). With the rainy winter, the trails were often soft and squishy, and this helped a great deal to soften the impact for my hurt foot.

By March, I was just starting to feel normal again, until I pushed too hard one day. I could feel something in the fascia “ping” and was back to pain and rigorous icing again. It was clear I wasn’t going to race anytime soon. We volunteered at Skyline-to-the-Sea in April, but my foot was killing me just from standing around all day. I went back to track workouts, thinking the soft springy surface would help. I also did running drills, not realizing these would exacerbate the problems. With more PF pain and weird associated pains and numbness, I finally broke down and went to see a podiatrist in an attempt to find out what the heck had happened and whether I had a stress fracture or something serious. Several x-rays and CT scans later, he informed me I had dislocated a bone in my foot nearly a year before! As a consequence, the foot joints had been trying to compensate for the injury by growing larger and stronger, hence the longer left foot. He also said it looked like I was getting some arthritis too. He instructed me to ration my running, run on soft surfaces, use an insole and to take glucosamine/chondroitin sulfate pills. (As an aside, he was also appalled at the looseness of my left ankle ligaments and advised me to run with an ankle brace, which I do- it has saved me from further injuring the ankle at least). So for the next month, I stuck with trails, the softest I could find and ran gently—no more “speed” work!

By May, it was time for Quicksilver 50K again, the scene of the original injury. I was determined to run it again, not sure if it would be the last ultra for a long time. I wanted to look for the offending stream crossing and this time cross it sensibly, but never did find it (I think they put up a bridge). This race was slower than last year by 23 minutes, but my foot didn’t hurt until after 15 miles. The after effects were fine too—less pain if anything. Encouraged, I signed up for the famous and popular Ohlone 50K two weeks later (I got lucky on the wait list), which involved a lot of slow trudging up hills and fast downhills trying to make up time, and I was pleased that my foot wasn’t a limiter, not seriously. We got lucky with a cool spell of weather on this one too. My lack of ability to run those hills was by far the biggest limiter. And again, the after effects were minimal. I was so excited to get through Ohlone without further injury that I went out and injured something else by running too hard (one of the little gemellis or something in the butt—the little bugger still hurts).

David and his son Ethan decided to run the SF Marathon this year. I played “coach,” leading them through a 30 minute time trial to assess training paces, long runs, hills runs, and mile repeats and Yasso 800s on the track. I couldn’t keep up with their pace, but tagged along behind. We did short trail runs at first to keep the impact lighter to help Ethan work up to longer distances without injury, but quickly escalated to 17–25 mile runs (I only did 20 miles that day) when it was clear he was weathering the distance without his previous injuries reappearing. Being injured yet again, I took it pretty slow and used this as a build phase. By marathon day, they were both primed and ready (though as it turns out, David had pushed too hard already and had some limiting injuries), and gave 3:37 and 4:12 performances.

So by August 1st, I was eager for another race, this time Skyline 50K. This race was extremely well organized and fun, with friendly volunteers positioned at trail junctions pointing the right direction frequently during the race, it was not possible to get lost. The course was harder than I expected, even though it is ostensibly completely runnable (just not for me), because some sections are very steep and rugged. I was amazed to read Jean Pommier’s account of running 7 minute miles through the parts that had me picking my way carefully over roots and rocks, averaging 15 minute miles!

Two weeks later marked the August 2010 (instead of September or March) running of the Steven’s Creek 50K. The event was well run this year as well, though our weather was not as considerate and became hot, while last year was unseasonably cool. I met Roger Jensen (“the yo-yo guy”) and Gordy Ansleigh here. Roger planted the seed for running Rio del Lago, saying that he and Barbara Elia would be there. I ended up finishing a little ahead of Roger, and thought Hmmm…

For these races as well, my foot just wasn’t the main limitation—it still hurt sometimes and made me run cautiously and tentatively at times, but after the races seemed better than before, if anything. But by the time the next weekend came around, I had put in 61 miles for the week and everything started to rebel. I had aches at the Achilles insertion into the calcaneus, peroneal brevis (or longus) tendonitis (maybe) in addition to PF (but the buzzing and tingling of nerve entrapment has finally gone for good I think). I blamed running with extra weight for aggravating the ligaments, but I certainly don’t understand what causes it to flare up on occasion still. So, a couple of easy cutback weeks were in order. I watched and pampered the foot during these weeks and then on the last possible day signed up for my first 100 mile race. Stay tuned for this next misadventure!

So the upshot is that over the last year, an impact injury with dislocation resulted in significant remodeling of foot structure, resulting in PF and other aggravations. It’s possible if I had gone to have it checked out right away, all of these problems could have been avoided, although I’ve heard stories about residual effects of injuries in people who were careful to get everything checked out. I now wonder whether PF is generally the result of minor or unnoticed foot remodeling. After all, the fascia is very inflexible, and changes in bone structure in the foot increasing the length of the foot of only a few mm could result in changes in tension in the fascia, possibly in stretching and tearing injuries. I was able to keep running, but not as fast or as far as I wanted. I had to give up my beloved Inov8’s because my feet seemed to hurt more wearing them than my uber-protective Montrail Continental Divides (sadly, no longer available). I also tried La Sportiva Cascadias and Salomon XTs, which are great shoes, but not as easy on my feet. I got into a routine of easy runs with prophylactic ibuprofen, which seemed to help prevent the majority of the inflammation, then I’d have to sit around for several hours icing my foot. It gradually got better so that it no longer hurt after running most of the time, and did not hurt when getting out of bed in the AM, but still requires a lot of maintenance and pampering. I’ve been able to manage mileage of 20 to 50 miles per week throughout the year, but have to be prepared to cut back at signs of aggravation. At various times, the pain has caused me to run with an awkward running gait, twisting of the knee or ankle (trying to avoid direct pressure on the heel), differences in foot falls (midfoot or forefoot on the left while heel strike on the right), all possibly leading to additional injury if not careful. I can really see the difference on potentially fast downhills, where I find myself holding back for fear of re-injury. I am optimistic, but would not be surprised to have to put up with this for another year or more. It’s looking less and less like I will ever run as fast as even a 6:30 (hilly) 50K again, but at least I can still get out there, and I am grateful for that. Luckily for most PF sufferers, their injuries are more minor and will resolve more quickly.

David’s experience

It has been a rough year for both of us in the running area. David strained his popliteus muscle in May 2009 (sprinting on the track in his new VFFs), and shortly thereafter pinched his meniscus, probably as a result of his knee misbehaving due to his first injury (one injury begets another). He ran with a knee brace for months, and as a result of this knee tenderness was not willing to run Steven’s Creek 50K (he volunteered) or Firetrails in 2009, but instead agreed to be my pacer. Sometime in late Fall 2009/early Winter of 2010, David also developed plantar fasciitis, in the same foot as me. We’re not sure why, or if it was related to some adjustments he made due to knee pain he had from the previous injury, or due to excessive strain when adapting to using VFFs. His PF never became as rabid as mine, and he has managed to recover without suffering too much. It didn’t seem to bother him in the Fremont Fatass 50K or the Second Saratoga Fatass 50K, though he was definitely slower at the Overgrown Fatass Marathon because of it (and also something of a real tenderfoot on that rugged trail with his VFFs). So he has spent some of the past year also icing his foot, along with physical therapy exercises too (lots of ankle work and calf raises).

Then while training for the SF Marathon, he injured a psoas muscle and one or two adductors. Though seemingly minor, these became aggravated during the race so that he was unable to run his best pace. Afterwards, we noticed he had a big lump on his Achilles tendon, so he is treating all of these new injuries with caution and easy running. David is convinced that it was speed work that was problematic and led to injuries; he’s never had any problems from the longer, slower distances. I am reminded of one of Gordo Byrn’s posts about how big men (i.e., ≥ 6 ft tall, > 165 lbs) benefit from easier training (“Small women get fast from intensity, big men get fast from volume.”). This certainly seems to be true for David. He seemed indestructible when he first started running with me, but then he never had to strain very hard to keep up with me and was always able to stay within his body’s limits. Avoiding high intensity training doesn’t seem to have prevented him from running faster than me!

Weight Loss Followup

2010-06-30T17:53:00.000-07:00

In previous posts, we discussed the first several months of weight loss for Cynthia and David. We’re now about two and a half years into our new eating lifestyle, and it seems like a followup post is overdue.

We have been taking near daily measurements through the period with some more occasional measurements of other parameters, so we have lots of data to misinterpret according to whatever bias or slant you might want to apply. As usual, life is complicated, and the data are subject to a lot of coarse- and fine-grained hypotheses that can be postulated to explain various features. We’ll offer an assortment of hypotheses, some of which are more strongly supported by the data than others. Since it’s all basically post-hoc analysis based on two subjects, none of the hypotheses can really be considered confirmed.

The most striking observation, perhaps, is that the change to lower-carbohydrate consumption continues to be working. (Let’s not call it a “diet” since that seems to mean something that people try to use as a temporary measure that ultimately fails when they revert to “normal” eating habits.) While our weight loss has inevitably slowed and had various “plateaus” and “reversals” or “setbacks,” our weight loss is holding and we are both at or near our lows of recent years some 30 months into our new eating habits. This bodes well for the long term. We are emphatically not counting calories, calorie restricting to the point of gnawing hunger, or otherwise depriving ourselves of the enjoyment of eating. Sure, we are emphasizing some different foods and limiting consumption of sugars of all sorts and simple starches, but, for the most part, we don't crave them and can satisfy what cravings we have with either small portions or satisfactory substitutes. Fortunately, we don’t often share meals with the high-carb/low fat crowd, so we don’t face a lot of peer pressure to “cheat,” and we stay away from the French bakeries. There are some differences between our preferred diets as well. David tends more towards the “Optimal Diet” (lower carb and high in butter and cream) while Cynthia gives in more to carb cravings (more fruit and indulgences such as Chinese dumplings), to which she attributes her various weight stalls and reversals!

And, of course, at least among those who are open-minded enough to have actually investigated the current state of the science, acceptance of the low-carb lifestyle has been increasing steadily. While advertising by the food industry continues to be abysmally misleading, we’ve noticed an increasing number of more positive references to low-carb nutrition in everything from a steadily increasing number of blogs posts, books, and scientific papers to passing references in recent movies (e.g., “She eats CARBS” from The Devil Wears Prada). The mainstream government agencies and medical societies are generally still not recognizing the error of the low fat diet, as seen in the 2010 USDA guidelines. (Quoting from Question 5 in Appendix E-1, “Conclusions”: “No optimal macronutrient proportion was identified for enhancing weight loss or weight maintenance. However, decreasing caloric intake led to increased weight loss and improved weight maintenance. Therefore, diets that are reduced in calories and have macronutrient proportions that are within the ranges recommended in the Dietary References Intakes (IOM, 2002/2005) (protein: 10%-35%; carbohydrate: 45%-65%; fat: 20%-35%) are appropriate for individuals who desire to lose weight or maintain weight loss. Diets that are less than 45 percent carbohydrate or more than 35 percent protein are difficult to adhere to, are not more effective than other calorie-controlled diets for weight loss and weight maintenance, and may pose health risk, and are therefore not recommended for weight loss or maintenance.”) There are, of course, huge entrenched economic interests that will continue to fight the status quo tooth and nail. There is some evidence that they may start to crack in the foreseeable future—for example, the American Diabetes Association now recognizes that a low carb diet may be useful for weight loss in diabetics—but progress continues to be slow.

Then there’s the exercise wild card. We all “know” that increased exercise is a “necessary” part of any “reputable” weight loss program. And yes, we have increased our level of exercise. We were never serious couch potatoes, but we weren’t serious athletes, either. Very roughly, we were running 20–30 mi/wk two and a half years ago, and increased to 30–40 mi/wk, and have often done closer to 50 mi/wk. We also started running ultramarathons of 30–50 mi in one day, averaging more than one such event per month at times. So what did all that exercise do for us? Well, we certainly got stronger and faster. We generally feel good and energetic (aside from the inevitable sore muscles and minor injuries). We also continue to find that more often than not, increased exercise correlates with weight gain, not weight loss! This happens both over the short term
(water weight of up to a few pounds the day after an ultra-marathon that may take a few days to lose), and over the longer term (our weight loss trends reversed for about 4 months after we started doing frequent day runs in excess of about 15 mi). We also tended to see a stalling of any downward trend whenever we increased our weekly mileage significantly. Partly, this is because moderate mileage increases such as this are easily compensated for by eating more. There are exceptions too, for example, during August 2009, Cynthia upped her mileage considerably (>50 mi/wk) and found she could not eat enough to keep her weight stable. However, this amount of mileage was not sustainable (due to an injury in May 2009 that began to cause pain), and eventually she gained it back.

There are, of course, several competing things going on when you exercise a lot. Over the period of the exercise itself, the dominant effect is usually level of hydration, and body weight is often used to monitor endurance athletes for dehydration and/or over-hydration. If you exercise hard enough and long enough, you can also deplete your glycogen stores to account for another pound or so of temporary weight loss (including the accompanying water of hydration). So generally speaking, you usually finish a long, hard bout of exercise down a few pounds. But then, of course, you eat and drink. Your appetite increases, so you may eat more than normal, and there are various reasons why you might retain extra fluid. That’s why we frequently saw a net increase in weight the day after. Interestingly, the size of this effect has generally decreased over time. Probably, as our bodies have become better adapted to the rigors of a long, hard day of exercise, they no longer see it as stressful. This is supported by the evidence of less muscle soreness and edema, as well. In David’s case, there is probably also a nutritional effect. He ran earlier events consuming more than normal carbs during and immediately after the event, and then, in later events, switched to more strict low-carb fueling before, during, and after. Some amount of fluid retention would be expected to be correlated with a temporary increase in carb consumption, and eliminating the carbs apparently eliminates that source of fluid retention. Cynthia tends to push harder into her non-aerobic zone, especially when trying to keep up with David, and chooses to consume more carbs during and after long runs, but she’s been showing smaller post-event weight spikes more recently, too. The effect is a sensitive measure of training, because it is more pronounced when less prepared or perhaps as a response to heat stress. The water retention is most likely due to a complex interplay of hormones that signal the kidneys to retain salt and fluid. Such a response is understandable after the stimulus of long and/or hot conditions.

The increased appetite can generally overcome any predicted weight loss from a purely thermodynamic point of view. The problem is that you have to run on the order of 30 mi or so to burn enough calories to consume a pound of body fat (assuming that you’re actually burning fat for fuel). If you do that over a week, it’s pretty easy to unknowingly increase your daily food Calorie consumption enough to more than offset that burn. It’s not much more than an extra couple of “servings” of something tasty per day. Be careful about rewarding yourself with too many bowls of ice cream or extra double cheesburgers!

An increased level of exercise, if done systematically and with adequate general nutritional support (enough protein, for example), often results in muscle building. This can result in body “recomposition”: loss of body fat and increase in lean muscle mass with no net change in weight. That may explain some of the apparent plateauing of our weights. Running doesn’t build bulky muscles the way, say, weightlifting does, but we have seen some measurable changes in body measurements.

Nevertheless, with a very blurry-eyed look at the weight loss data over 30 months, a simple-minded interpretation and hypothesis is that we both generally lost weight more or less linearly for 8 months until we started seriously increasing our level of exercise and then stalled out, remaining at a more or less constant weight for the following 22 months. (Click on figures to show larger.)

With slightly less blurry eyes, one immediately notices that longer trending period tends to follow more of an exponential curve rather than a straight line. A simple model which can be made to fit the data pretty well is to assume that you are always approaching an asymptote (target weight) exponentially so that your rate of weight loss (gain) gets steadily slower as you approach your target. Fitting such exponentials to the various regions on our graphs gives a pretty good fit (i.e., the data looks like it fits a set of straight line segments on a semi-log plot where an estimated target weight is subtracted out). Measured time constants vary from about half a year to two years. And while our weight loss is now hard to see from day to day or even week to week, we are still losing at an average net rate of about a pound every 2–3 months. We both feel like we should be able to lose another 10–15 pounds, but that could take a few years.

It is interesting to treat the data using some of the technical indicators typically used on financial charts. For example, one can draw upper("resistance") and lower ("support") levels and trend lines. Weight can bounce off or break through these lines as you can see on Cynthia's chart from August 2008 through February 2010. You can also see a downward trending channel or notice triangular patterns with converging oscillations, double bottoms, retracement levels, all very similar to observed price behavior on financial charts.

There are other secondary effects that may also be present in the data. While we have so far explained the weight gain last fall as due to increased exercise, it could also be due, at least in part, to a normal seasonal effect. Some weight gain through the fall and into mid-winter is perhaps genetically programmed to store fuel for the winter. Some of it may also be just increased fluid retention in cooler weather (or just reduced dehydration?—the body probably undergoes larger hydration cycles in hot weather as one sweats and eventually replaces lost fluid—but note that a drop in core body temperature actually has the reverse effect as anyone who dives in cold water can attest: the body naturally sheds excess water when cold).

Cynthia's data also show a pronounced oscillation with an amplitude of 4–6 pounds and a period of 1.5–3 months. We have, so far, been unable to correlate this oscillation with any obvious body cycles, lifestyle cycles, eating, or exercise habits. Being female, one might suspect menstrual cycle effects, but the period is too long and the amplitude is too large. (Menstrual cycles generally result in monthly weight variations with an amplitude of about 2 pounds. In order to see it, you typically have to average several months of data [with the end dates of cycles carefully lined up if the length of the cycle is at all irregular] since the amplitude is comparable to normal day to day fluctuations. It's actually more noticeable as a cyclic change in waist circumference.)

David's data show periods of unexpectedly rapid weight loss (July/August 2008, January/February 2009, May/June 2010). Again, we have not been able to clearly explain these periods, although similar “success” periods seem to be commonly reported anecdotally. Perhaps the body suddenly decides to adjust its natural setpoint in some important way. Fat storage and loss is driven more by hormonal signals than by daily calorie balance anyway.

If you want to keep losing weight, you may need to keep reducing your calorie consumption as well. In principle, this should happen automatically if you basically eat to satiety, but eating habits can often be somewhat independent of satiety if you are in the habit of eating particular portion sizes (e.g., 2 eggs and 2 slices of cheese, etc.). Presumably with a little conscious effort, you should be able to readjust your habits to your new needs as you lose weight, but some portions are a little hard to adjust. (It’s not convenient to cook 1.8 eggs for breakfast…)

Another interesting comparison is to plot David’s weight vs. Cynthia’s weight. This plot is noisier in that David’s and Cynthia’s weight gain and loss have not always been tightly correlated despite similar diet and exercise schedules. Overall, David’s weight is approximately 30% higher than Cynthia’s at any given time, but he has been losing about 1.2 pounds for each pound that Cynthia loses. We're still not sure how much more weight we can (or should) realistically lose. The corresponding weight loss rates are consistent with our college-age weights of about 167/125 pounds respectively, but a more realistic goal may be more like 175/133 pounds.

There are other measures of body composition that are often used to determine “ideal” weights. The most commonly used is the Body Mass Index or BMI. This is based purely on height and weight and does not take skeletal build or musculature into account at all. David is still classed as borderline “overweight” by standard BMI guidelines; Cynthia is “normal” at a BMI of ~23.

However, David is relatively well-muscled and big-boned. At least by current American on-the-street standards, most people would not say he was overweight at this point. Another approach to determining ideal body composition is to estimate percent fat. There are many ways to make this measurement—all approximations based on indirect measurements of one sort or another.
Underwater weighing is the current standard against which other measurements are typically evaluated, but it is imperfect, too. Skin-fold thickness is also popular, because it’s easy, but it can be unreliable. See Lyle McDonald’s post for more in-depth discussion. The two methods that are most readily available to most people (including us) are Bioelectric Impedance Analysis (BIA), a measurement built-in to some digital bathroom scales, and various formulas based on using additional body dimensions such as waist, hip, and neck circumference. Our favorite of these right now is a set of formulas derived by the US Navy based on height, waist, weight, neck, and hip (women only): %Fat=495/(1.0324 - 0.19077(log(waist - neck)) + 0.15456(log(height))) - 450 for men or %Fat=495/(1.29579 - 0.35004(log(waist + hip - neck)) + 0.22100(log(height))) - 450 for women. These give current values of 28.5% fat for Cynthia and 18.5% fat for David. Not surprisingly, these calculations put both of us solidly in the “acceptable” range, but still significantly above the upper end of the target ranges for athletes (presumably based on a young military test population: 20% for women, 13% for men). Just to give you some idea of the uncertainty in these measurements, the BIA method as implemented by a Weight Watchers bathroom scale gives 25.4% for Cynthia and 22.4% for David, showing discrepancies on the order of 3% and in opposite directions for Cynthia and for David.

And finally, just a quick observation about the Weight Watcher brand scale implementation of the BIA measurement: while we have been unable to locate any information on the algorithms implemented in the scale, it is clear that there is more than a little something amiss. First, it tends to report %Water in the mid-50s, while the human body is generally estimated to be closer to 70% water. While the instructions warn you that the data may be inaccurate if you take measurements immediately after heavy exercise or large fluid consumption, it is nevertheless disconcerting that it actually tends to report higher %Water (and lower %Fat) after losing a lot of fluid due to exercise and sweating, and lower %Water after a large drink! Clearly the algorithms and/or measurements fail to accurately account for variations in the distribution of fluid throughout the body. Another anomaly we have noticed is that the scale has reported a slight decrease in %Bone for both of us as we have lost weight, something that is very unlikely to be valid.

So all in all, our way of eating is pretty easy to sustain and requires no weighing or measuring. If we really wanted to lose weight faster, I'm sure it could be done using more discipline, but then we'd have to worry about regaining once the discipline slips. This way the changes are more gradual, and perhaps, more sustainable.

Vibram Five-Fingers, 1200 Miles in

2010-02-10T22:30:00.000-08:00

Most reviews of running in Vibram Five-Fingers “shoes” are necessarily based on a few days to a few weeks of experience. Journalists, of course, rarely have any longer time horizon available to them since they need to get something out promptly. My own first review was based on a couple of months of experience; this is a follow-up report now that I’ve been using them for some 8 months and 1200 miles.

“Barefoot” Running?
Do I now consider myself a “habitual barefoot runner”? No! I’ve definitely gotten solidly past a transition period away from conventional running shoes and now run (and do most things where I need shoes and can get by without more complicated foot protection) exclusively in my Five-Fingers. However, my feet don’t have good abrasion resistance yet. I can run 3–4 miles on “good” surfaces such as real or artificial turf, smooth dirt, rubber track surfaces, and the like, and up to about 2 miles on rough surfaces such as gravel or rough asphalt or concrete, but for longer distances, I need to wear something on the bottom of my feet to avoid blisters and hot spots. I have no plans to run any organized events barefoot anytime soon, though I will continue to go barefoot for less strenuous activities whenever I think it is safe to do so.

That said, of course, running in minimalist shoes, whether Five-Fingers, moccasins, sandals, or other commercial attempts to provide a near-barefoot experience, does allow you to mimic a lot of the characteristics of barefoot running with our modern typical fragile foot bottoms. Musculature and fat pads adapt more quickly than abrasion resistance, though these, too, require some real adaptation leading to a lot of early problems for people that try to do too much too soon.

Running Style
Whether running barefoot or in minimalist shoes, you rapidly discover (if no one tells you first), that you probably want to move away from the sort of heel-strike running gait that most shod runners are taught to use or use instinctively for anything beyond short sprint distances. True habitual barefoot runners (such as those who grew up not wearing shoes at all) do not use a heel strike. The high shock associated with landing on your heel without any possibility of shock absorption by the foot causes heel bruises and other unpleasant feelings (such as more strain on the knees) if you don’t have any shoe structure to absorb the shock of heel-strike running. Sprinters run on their forefeet and generally don’t let their heels touch the ground at all. But for longer distances (more than about 30 seconds of running), most runners do allow their heels to touch even if they don’t land on them.

There are many possible variations on the exact gait one can use when running in minimalist shoes. Personally, I strive for efficiency as an endurance runner (I’m definitely not a sprinter), and I find that the gait I use for most routine running keeps my feet low to the ground, and my stride length perhaps a little shorter than it used to be. I land first (just barely) on the inside edge of my forefoot and roll the ground contact across the ball of my foot and then back along the outside edge to my heel which just touches the ground with minimal force and then comes back up to reverse the movement until the foot leaves the ground again. This motion, of course, makes full use of the natural structure of the foot and provides maximum opportunity to use all available ligaments, tendons, and muscles for shock absorption, energy storage and release, and push for the next step. I think this is true regardless of your foot type (within normal variations). I happen to have rather flat arches, but I don’t think my minimalist shoe running style is particularly different from that of someone with very high arches. I haven’t yet seen any data on wear patterns for the soles of minimalist shoe runners. Anecdotally, there is still some variability in the location of maximum wear, though much less so than is observed for “normal” running shoes. I think I am seeing what I think is the most common pattern, finding that the point of greatest wear is on the inside ball of the foot and the big toe.

[Addendum 11 February 2010: (thanks to Tuck for making me look more carefully at Daniel Lieberman’s pressure-plate video) It seems that exactly where you naturally strike on your forefoot depends on your particular foot structure. I have rather flat arches and a tendency to pronate (turn my foot inward) which is manifested in a tendency to wear the inside edge of the heel of shoes when running with a heel-strike gait. In a forefoot gait, I land first on my first metatarsal and then transfer weight to my big toe, then across the rest of my metatarsals. Daniel’s pressure plate video (presumably of himself running) shows initial pressure buildup under the fourth metatarsal with a roll toward the first metatarsal. Presumably he does not tend to pronate and likely has higher arches than I do. If you don’t have access to time-resolved pressure plate data recording equipment and don’t want to wait a few hundred miles to analyze shoe wear patterns, here’s a simple trick I found that should tell you how you should probably land: Stand up (barefoot) with your leg forward. Point your toe (i.e., bend your foot forward), but keep your ankle in a neutral position laterally (don’t consciously turn it either in or out). Now touch your foot to the ground. When I do this test, I touch with my first metatarsal and/or big toe. Cynthia, on the other hand, who has high arches and no tendency to pronate, touches on the fourth metatarsal. While there are some people who try to get everyone to do the “right” thing meaning the same thing they do, it is my belief that there is no right or wrong way to use your foot. You should do what is comfortable and natural for your particular bone and ligament structure. For me, while I could force myself to land on my fourth metatarsal, it would be an unnatural thing to do and likely cause undesirable side effects in the form of muscle strain.]

Landing on your forefoot results in a gentler landing with less force against the ground, less shock on the knees, and less noise. You become the proverbial Indian brave, able to run quietly through the woods in your moccasins (or equivalent). In fact, one of the ways that you can further train yourself to reduce stress is to aim for the quietest running that you can achieve. There is still a range of impact force that can be used with forefront landing, and a good way to aim for lower impact force and greater running efficiency is to listen to your running and try to keep it as quiet as possible. You may need to ramp up the noise a little bit again when you’re out to get maximum speed, but for most routine running, quieter is probably better.

While I am primarily a trail runner by temperament, one surprising (to me) consequence of switching to a forefoot landing habit is that running on hard surfaces such as roads is no longer something that I shun. Since I am now a gentler runner, long distance pavement pounding is just not nearly as stressful as it used to be, and in fact, all else being equal, I now find myself seeking out the smoother harder surfaces rather than running on the adjacent dirt if both are available.

Another aspect of running in minimalist shoes is that you are less constrained to hold your foot in a particular orientation relative to your leg. Most of the time this doesn’t matter all that much. But if you happen to be contouring along a steep hillside or placing your feet on the sides of a deeply rutted trail, you may find yourself needing to adapt to a surface that is far from perpendicular to your leg. In shoes, this can be an unpleasant ankle twisting (and even ankle spraining) experience. But with Five-Fingers shoes you can take up most of the extra bending in the foot rather than the ankle with structures that are much better adapted to the bend than is the ankle. This is an aspect of barefoot/minimalist shoe running about which I’ve seen very little comment. I discovered the phenomenon accidentally one day when I found myself running along the side of a very steep hillside, cutting across an open field. I suddenly realized that the running was much easier and much less stressful on the ankles than I would have expected.

Muscle and other Soft Tissue Development
Any change in running style—whether due to a change in footwear, compensation for injury, change in running surface, distance, or terrain—will stress muscles in new and different ways. Most notably, switching from heel-strike to forefoot running increases the dependence on muscles associated with the feet. The strongest of these muscles are actually located in the lower leg and connected via an elaborate system of ropes and pulleys (a.k.a. tendons, ligaments, and fascia) to the bones of the foot. Runners who transition too rapidly from heel-strike to forefoot running often experience at least pain if not outright injury in their lower leg muscles as well as their Achilles tendons and plantar fascia. As with any transition, the key is to start slowly—less than a mile for the first few days, increasing gradually as muscles allow. Plan on a minimum of 2–3 weeks of gradually increasing distance, speed, and difficulty, and preferably at least twice that long. Back off if you experience any significant pain. If you want to supplement your actual running with other training, then anything that puts you on your toes (calf raises, skipping rope, dance or fencing exercises) can be useful cross training.

How did I fare during my transition? Well enough. I had an enforced reduction in mileage about the same time I made the transition due to an unrelated injury. I’m finally fully recovered from that injury, and I actually think that forefoot running and the associated reduced knee stress helped me recover more quickly and increase mileage again more quickly. I’m presently contending with a mild case of plantar fasciitis in one foot—nothing that is limiting my running at all, but annoying all the same. Again, I find that forefoot running is less stressful on the injured tissues.

Padding
Of course, one of the main things that people wonder about, especially for trail running, is the issue of how you can run on rough surfaces without much cushioning from a shoe. Running on surfaces with a lot of small stones (rocky trails, gravel roads with relatively little actual gravel) is the most challenging. It takes a while to toughen the pads on the balls of your feet, but it does happen. The improvement is gradual and takes easily 3–6 months depending on how you train. Eight months out, I find that surface that used to leave my feet feeling beat-up after a few miles no longer bother me at all. I can run 10+ miles on very challenging trail surfaces and come home feeling unaffected. A recent 50K run that included a lot of gravel trail still left me feeling a bit worked over, but my feet were fine again by the next day.

The older models of Five-Fingers shoes (including the KSO model that I wear) have practically no tread or padding in the sole. In response to customer feedback, newer models incorporate some tread which also provides a little more damping out of the running surface roughness. Since I haven’t had an opportunity to try running in the new models, I can’t comment except to say that, now that I am well-adapted to running with the older thinner soles, I don’t feel any particular desire to have more protection under my feet than what I’ve got now. From a marketing point of view and the usual sort of instant gratification that many customers will want, I’m sure that a bit more sole will be a good thing; for more experienced minimalist runners like me, it doesn’t seem that more sole has any compelling attractions.

I also noted an unexpected pattern to the toughening of the pads on the balls of my feet. There is a transverse arch across the ball of the foot, and I, at least, expected that not much would happen in the middle of the arch (behind the second toe), thinking that the primary stress would be on the outsides of the arch. In actuality, the reverse happened. The most toughening occurred precisely in the middle of the arch, and there even tends to be some slight callous development there! Apparently, the transverse arch flattens completely on impact and the middle experiences as much or more force than the outsides even though the initial contact and maximum sole wear points are on the outside.

Traction
As I just noted, Vibram has recently introduced newer models that include more familiar looking shoe bottoms that have some lugs that provide both more padding and maybe more traction. After 1200 miles of running on varied surfaces including concrete, asphalt, rubber, dirt, mud, sand, rock, turf, fields, etc., I can say that I have almost never felt at a loss for traction in the KSO model soles. These soles are smooth flat rubber with laser-cut zig-zag patterns that increase grip on smooth surfaces. The only surfaces that I have found difficult to deal with are those with thin slippery mud which are challenging in any footwear (though probably respond better to lug soles than smooth soles). Deeper mud and soft sand/ash present no difficulty—the toes work very well to provide good grip and traction. Wet surfaces are generally not a problem—the rubber grips well. I don’t recommend Five-Fingers shoes for snow and ice, but under such conditions you probably want more thermal protection anyway, never mind the traction issues.

Foot Protection
Minimalist shoes clearly provide less protection for the foot against all sorts of insults. You wouldn’t want to wear them anywhere where normal safety practice would dictate steel-toed safety shoes, for example. You won’t get much protection from ankle twists, kicking hard objects (rocks and roots), sharp objects, others stepping on your feet, etc. If you need arch support or ankle support, you won’t get it (though some people who have failed to get much relief from arch-related problems with all kind of expensive orthotics have found that going minimalist instead actually turns out to be more beneficial).

So what’s my track record after 1200 miles? Pretty good and getting better! Early on, I caught one little toe on a root and wrenched it badly enough that it hurt for a couple of weeks, but that’s probably the worst thing that’s happened. I’ve also kicked a handful of rocks and roots, especially running in poor light. I have to consciously work on lifting my feet more when I can’t see the trail surface very well. I’ve poked my feet into an assortment of sharp sticks now and then, enough to do some damage to the shoe uppers, but not enough to break skin. Not surprisingly, the more you run with minimal protection, the more you instinctively avoid problems. Just as I’ve found that my rate of falling (never very high) has gradually decreased over the years, my rate of minor foot trauma has declined to almost zero over the last several months.

One of my most annoying problems as a shod runner was toenail bruising. Long downhill runs where you are constantly jamming your toes against the front of your shoe cause the most trouble. Even with careful shoe sizing for plenty of toe room, careful toenail trimming, and various aids in the form of taping, toecaps, tubes, and the like, I usually found myself losing toenails due to such bruising a few times a year. Hilly ultra-marathons generally did the most damage. This was probably the single most important factor that drove me to try Vibram Five Fingers in the first place. In the last eight months I still lost one toenail, but it was the result of kicking several rocks in a row while running in the dark, so I’d have to argue that it was really my own fault. I just don’t have toenail jamming issues with Five Fingers footwear. You fit the shoes small. I wear at least a size 44 (European) in most running shoes, but only a size 42 in Five Fingers. Your feet don’t slide inside the shoe. The front of your foot between the toes hits fabric and prevents the toes from jamming into anything.

Socks
Five Fingers shoes are usually worn without socks, though they can also be worn with toe socks such as those sold by Injinji. I started out wearing socks more often than not, and especially for runs of more than about an hour and when the weather was warmer (my feet tend to sweat more in hot weather). As time has gone on, I wear socks less and less; I just don’t need them. I almost never wear them for runs of less than two hours now, and I’ve done a full (winter) 50K without socks. One key to running without socks is to remember that the shoes, in effect, become your socks. So just as you wouldn’t wear socks again after a long run without washing them, you need to wash your Five Fingers regularly. You also need to make sure that your feet are really clean before you stick them into your Five Fingers. I regularly use a pumice stone to remove all surface debris from my feet including any sticky dirt and grease. That keeps the inside of the Five Fingers much cleaner and minimizes accumulation of junk that can cause abrasion. I wash my Five Fingers after any long run, any muddy run, and any very dusty run, and at least once a week regardless. After my 50K run, I did have a couple of minor blisters that I hadn’t realized I’d gotten. They were on the inside side of both feet in the arch region at a seam. I’ll probably opt for socks on future 50K+ runs just to protect myself from this particular hazard.

Keeping Stuff Out
The KSO model is named for “keep stuff out.” It has elastic fabric over the top of the foot that fits snuggly. It works! I’ve never had to stop to take my KSOs off to remove debris. I can’t say the same of any other shoes I’ve ever run in. KSOs still don’t keep everything out, though. They don’t keep water out, and they don’t keep fine dust out. After running in dusty conditions, your feet will look like you have dirt socks on. But I’ve never had any trouble either from dust or from wet feet. Neither has caused any harmful chafing. I consider myself fortunate to have ended up with the KSO model; other runners I’ve talked to that have ended up with other models that don’t have fabric over the top of the foot do have problems keeping stuff out.

Durability
Shoe manufactures would like you to believe that you need to replace your running shoes every few months or every few hundred miles whichever comes first. I never really bought into that plan, running happily for many months and miles in nominally worn-out shoes. Nevertheless, I am still impressed by how few signs of wear my Five Fingers show after 8 months and 1200 miles. They should be good for many more miles to come. That’s not to say that they have been completely problem free. There have been a handful of holes and seams to repair particularly wear I’ve poked the fabric with sticks. These are easy repairs to make since the material is just a cloth fabric that is easily sewn. The soles are holding up well. There is visible wear, but since there are no lugs to wear off, the wear is spread over more surface area. I have not yet needed to add any material to the soles and may not need to over the life of the shoes. As yet, I still can’t tell what the ultimate end-of-life failure mode is likely to be.

The most serious design flaw from a durability point of view in the KSO model is the strap and the slot through which the strap passes on each side of the foot. The strap is made from a relatively thin nylon fabric, and the slot is reinforced with a hard plastic resin. The nylon rubs against the edge of the slot and wears through after a while. I have so far dealt with the wear by reinforcing each strap where it goes through the slot with some thin leather. If I ever have to actually replace the strap, I will try to find some heavier duty material to use. But if I were to change one thing in the design of the KSO Five Fingers, it would be the choice of materials for the straps and slots.

Another weak point in most running shoes is the insoles. These often wear out before the rest of the shoe and need to be replaced. However, with my careful cleaning habits (both my feet and the shoes), I see no signs of wear at all yet on the insoles of my KSOs. When I wash them, I am careful to clean the surface of the insoles of any accumulated dirt and grime. I’m sure this helps. In fact, I suspect that the combination of clean practices and the natural tendency of the KSOs to keep stuff out are the primary reasons for my good experience.

The newer models of Five Fingers intended for trail runners have switched to leather uppers. While I haven’t tried these out, I don’t presently view this as a positive change. I like my thin elastic uppers. They have proven to have adequate durability and are easily repaired when damaged, they breath easily to keep my feet cool, and they can be quickly washed and dried. I am skeptical that leather would perform as well.

—David

Bibliography
There is an ever increasing number of articles and blogs about barefoot running, Vibram Five Fingers and the like. A selected bibliography includes:
http://www.nature.com/nature/journal/v463/n7280/full/nature08723.html
http://www.runningandrambling.com/2010/02/vibram-fivefingers-kso-trek-review.html
http://www.runningandrambling.com/2010/01/invisible-shoe-huarache-review.html
http://www.runningandrambling.com/2010/02/barefoot-professor.html
http://www.runningandrambling.com/2010/01/declaration-of-dependence.html
http://www.runningandrambling.com/2010/01/brooks-ceo-jim-weber-on-barefoot.html
http://www.runningandrambling.com/2009/08/barefoot-revolution.html
http://www.sportsscientists.com/2010/01/running-barefoot-vs-shoes.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+blogspot%2FcJKs+%28The+Science+of+Sport%29
http://stevemagness.blogspot.com/2010/01/why-running-shoes-do-not-work-looking.html
http://stevemagness.blogspot.com/2010/01/first-big-study-on-barefoot-running-in.html
http://www.time.com/time/video/player/0,32068,62885933001_1955910,00.html
http://www.time.com/time/magazine/article/0,9171,1955580,00.html
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/09/02/BA1G19FFPH.DTL
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/10/05/DDG419E4P0.DTL
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/10/05/DDGB19VSQV.DTL
http://www.nytimes.com/2009/08/30/business/30shoe.html?_r=1&scp=1&sq=vibram&st=cse
http://well.blogs.nytimes.com/2009/09/01/have-you-run-barefoot/?scp=2&sq=vibram&st=cse http://well.blogs.nytimes.com/2009/10/05/the-roving-runner-goes-barefoot/?scp=9&sq=vibram&st=cse

Primal Potatoes—a Contrary View

2009-09-07T15:23:00.000-07:00

In a recent blog entry “Primal Potatoes, Part 2” the author tries to make the case that humans are evolutionarily adapted to include starchy foods such as tubers in their diets, and that there would be survival advantage in keeping glycogen stores higher using these sources of starch. We don’t disagree with all of the conclusions he ends up with, but we think that a lot of the “evidence” used is factually incorrect or misleading. Here’s our take:

There is no doubt that the human digestive system has broad adaptability. The fact that humans are “omnivores” who can digest most everything that any animals eat except straight cellulosic materials (grasses and dietary fiber) clearly provides a survival advantage in that it allows humans to survive for at least short periods on whatever food source is available. It does not follow, however, that the ability of humans to digest starches means that they provided a real performance advantage in hunting and/or survival activities and would have been a required part of our diet. Rather, it seems to us that humans are well-adapted to depend predominantly on aerobic exercise (fat-burning) which can be sustained for many hours even in a fasting state if necessary, using the generous fat storage capacity available. Humans have an auxiliary system able to use the much more limited glycogen (carbohydrate) energy stores for primarily short bursts of intense exercise (30 seconds or less at a time) or to supplement for higher intensities than can be sustained by fat burning alone. This auxiliary system is further adapted to replenish/restore itself fairly quickly, again, even without the aid of carbohydrate consumption. While it is possible to create situations in athletic training and competition where the rate of depletion can be faster than can be replenished in steady-state (especially for athletes who normally depend on carbohydrates for much of their calories), it does not follow that such rapid depletion followed by rapid replenishment using dietary carbohydrate sources, was ever important or necessary in evolutionary terms. Note, for example, that athletes in many sports routinely use “reps” or “intervals” of intense activity separated by recovery periods, typically with no consumption of food or drink during the recovery periods. To the extent that fuel stores are being restored during these recovery periods, the process does not depend on any particular external source of calories.

In effect, the body is so effective at conserving and recycling its limited stores of carbohydrate fuels that large dietary replenishment would not have been required to satisfy the needs of hunting and survival activities.

An article by Fournier was cited in “Primal Potatoes, Part 2” to support statements that “whereas typical glycogen stores will support an intense aerobic exercise for a few hours, a single maximal sprint effort will deplete one-third to one-half of glycogen stores,” and “humans can replenish glycogen stores without dietary carbohydrate, and even while fasting.” However, the article link did not work. A PubMed search found this article which appears to match the cited reference. The article describes experiments on rats which were made to engage in moderate exercise (swimming for 30 min with a weight attached to their tails), followed by a 3 min “sprint” (when a much heavier weight was attached to their tails). The main point of the article was to determine if the lactate produced during the sprint was the predominant source of carbon incorporated into newly synthesized glycogen. If you look at Fig. 1, you’ll see that the preceding “moderate” exercise depleted glycogen by at least 50% before the “sprint,” which then further depleted glycogen (down to ~25%). The researchers concluded that the lactate only provided ~50% of the newly synthesized glycogen, which actually is not surprising given that the previous glycogen depleting activity had already reduced the amount of glycogen available, and presumably any lactate that was or could have been produced and therefore recycled into new glycogen had already been oxidized completely and was no longer available. In short, the cited article does not support the first statement, which appears to be an exaggeration. There was no study showing that a single maximal sprint would deplete one third to one half of stored glycogen. Rather, the already ~50% depleted glycogen stores were further depleted by the “sprint,” showing only that the higher intensity the effort, the more rapidly the glycogen was depleted. A “single maximal sprint effort” as we understand it would most certainly not deplete a large fraction of glycogen stores. It may feel like it, but that feeling is not due to glycogen depletion per se, but rather due to acidification due to lactate and carbonic acid accumulation.

There is some confusion as to the meaning of the word “sprint” and how different available fuel sources are used by humans in sprint versus endurance events. True “sprints” (short bursts of maximal effort) do not even depend on glycolysis, which is too slow. There is a third energy storage and release system based on local stores of ATP and phosphocreatine. These are typically sufficient for about 7 sec of peak power output, and are rapidly regenerated during any rest periods using energy from aerobic glycolysis or fat metabolism. (See, for example, Noakes, Lore of Running, p 154.) But even a 100 m sprint by a world-class runner takes longer than 7 sec, and some energy must then come from glycolysis. Perhaps a single clean-and-jerk or other 1 rep maximum weight lift can be completed using primarily this sort of burst of maximal energy, but even a typical set of 10–15 reps in weight training takes longer.

Most people probably think of a “sprint” as something roughly equivalent to a 100 m or maybe as much as a 200 m maximum-speed run. Such efforts typically take about 10–30 sec to complete and, while not possible using only the local ATP and phosphocreatine stores, the effort can be completed mostly anaerobically, fueled by local glycogen stores. The 30-second maximum for this kind of effort is probably limited by the acidification resulting from the rapid production of lactate. What glycogen has been depleted can regenerate rapidly when the maximal effort ends. “Recovery” for a repeat of a similar effort largely consists of clearing enough of the accumulated lactate to relieve the sensation of “burning” in the muscles. Fuel depletion is not a major issue.

Three minutes of a “sprint swim” (or an 800 m run or a flight from a predator) is a much more complex sort of “maximal effort.” It is not a sprint as usually defined for humans. It is a “middle distance” that cannot be completed purely anaerobically. Even an 800 m run (2 min of effort for good runners) is considered an endurance event (requiring stamina), and much of the speed can be developed using aerobic training, though a maximal effort of this length will utilize primarily glycolysis and generate a lot of lactate temporarily. (See http://www.lydiardfoundation.org/news/pdfs/Snellcourirenglish.pdf.)

Clearly the maximum power output that can be maintained for a few seconds cannot be maintained even for 30 sec. A several minute effort is still in the range where a human is capable of power output that exceeds levels that can be sustained for much longer periods of time. The relative contributions of the available metabolic paths to energy generation for an maximal effort of a few minutes can vary widely depending on the individual, the level of normal activity, training or conditioning, dietary habits and adaptations, and the level of actual effort relative to the individual’s maximum capabilities over that distance or time. Anaerobic metabolism of glucose from glycogen is certainly one of the possible contributors. In fact, the limit to how fast any one individual can go for, say 3 min of “maximal effort” is probably still set by acidification caused by lactate accumulation (and carbonic acid from CO₂ produced) due to anaerobic glucose metabolism. As the anaerobic metabolism of glucose is very inefficient and would rapidly deplete stores, additional more efficient metabolic pathways will be tapped, most notably aerobic metabolism of fat and glucose. Another important contribution comes from the aerobic metabolism of the lactate (produced from anaerobic metabolism of glucose mentioned above). If lactate is being overproduced, some of its carbon will be further metabolized in the heart and muscles and converted to CO₂ through the citric acid cycle, and eventually breathed out, with most of the potential ATP from the glucose being realized eventually, even if not in the muscle of origin. At modest production rates, much of the lactate can be used aerobically and directly as fuel by the muscles, and is a preferred fuel of slow twitch and heart muscle. In addition to possibly being used by other muscles, this lactate is also taken up by the liver and converted back into glucose and then glycogen, and thus recycled. In short, it takes a lot more than a 3-minute burst of effort to substantially deplete glycogen stores. In fact, calculations show that the glycogen stores of a well-trained runner are sufficient to last for approximately 2 hours if glycogen is the exclusive fuel (and, incidentally, stored fat would last for about 59 hours [estimates based on glycogen and fat stores present in lean elite athletes]).

Thus, it is simply not true that there would be an urgent need to fully replenish severely depleted glycogen stores after a single episode of high-energy activity. The glycogen stores would not be significantly depleted (e.g., >50%); any of several available replenishment mechanisms would be sufficient to provide necessary restoration; and there is, in any case, no urgent need to provide complete restoration within 24 hours anyway.

This renders meaningless all of speculation in the post about the large amount of protein that would need to be consumed to replace the allegedly depleted glycogen. Let’s consider first, how the body actually uses its glycogen stores. Many authors tend to focus on how much total glycogen can be stored in muscles, how much activity that amount will support, and how much time is required to replace and completely refill the muscle glycogen stores. This way of thinking may be relevant when trying to achieve peak athletic performance for a particular competitive event, but this artificial effort would not be relevant to “normal” life and evolutionary pressures. In "normal" life, maximal effort may be required on occasion, but would be punctuated with adequate rest periods to allow recovery and maintenance of energy stores. Glycogen available to any given muscle for short intense effort is only that stored locally in that muscle—you can’t steal from other muscles. Similarly, once stored in the muscles, it remains there until used—it is not depleted beyond a certain level that is protected and maintained even after extensive exercise.

Even after an exhausting race, a person can still increase their efforts and sprint to the finish. A critical detail to remember is that lactate produced from glycolysis can be used to regenerate glucose and then glycogen, as well as enter the citric acid cycle and be used aerobically. Hence lactate is recyclable—glucose can be used anaerobically for a brief intense effort, then rapidly regenerated from lactate once there is a rest period. Under conditions of carbohydrate restriction or partial glycogen depletion, the body simply intensifies the recycling effort and favors use of fat for most energy needs. Only during periods of long and repeated exhaustive glycogen depletion would glycogen levels be dangerously low, and then the body would attempt to reserve them for emergencies, decreasing intensity of activity to levels supported by fat metabolism.

That said, the amount of glycogen storage for any given muscle is also “trainable” in that the amount of glycogen stored increases with increased use. A well-trained athlete may be able to top out his muscle glycogen stores at as much as three to four times that of a sedentary individual. And presumably, a paleolithic hunter is more similar to a modern athlete than to a couch potato. Further, the “normal” steady state condition for an active individual is probably not with glycogen stores full, but more like half full. This seems to be the condition measured for endurance athletes in steady state (i.e., several hours into a many-hour event or in everyday training. See Noakes, Lore of Running pages 101–102 and references therein). It may take a day or more of resting and relatively high carb eating to fully replenish glycogen stores to maximum capacity, but the half-full steady state can be maintained more or less indefinitely, and is fully capable of supporting most any activity that is needed. Further, at least for individuals adapted to fuel their activity primarily on fat, this steady state can be maintained with little or no carbohydrate consumption, and at levels of protein consumption that are modest compared to any levels that might overwhelm the kidneys.

A further point is that it is possible that this “half full” condition is optimal for health, in that muscles that are not topped out with glycogen are still hungry for more glucose, that is, they still express glucose transporters on their surface that are actively scavenging for glucose. This constant glucose uptake by hungry muscles would tend to keep blood glucose levels low, optimize insulin sensitivity and thereby keep insulin levels low, compared to the condition of the over-fed over-carbed SAD consumers. (See http://ajpendo.physiology.org/cgi/reprint/285/4/E729.)

As soon as liver glycogen starts to decrease, gluconeogenesis kicks in, and if adapted to fat burning, gluconeogenesis enzymes may be up-regulated. One can sustain aerobic activity (presumably using glycogen stores in addition to fat stores) for many hours and still have no measurable depletion of blood glucose levels! In fact, we routinely observe the opposite (elevated blood glucose after hours of running). Glycogen stores can thus be regularly replenished (at least partially- enough to call on in emergencies) as needed even during prolonged aerobic exercise, even when fasting, to support the needs of occasional anaerobic activity. As already noted, data indicates that trained athletes can maintain a steady state level of average glycogen stores that are approximately 50% of their maximum capacity. Put another way, during prolonged periods of inactivity, a trained athlete can store ahead approximately twice the “normal” levels of glycogen stores. (Note that even the “normal” levels are about twice those measured in sedentary humans.)

In the example given of hauling a buffalo carcass out of a ravine, this activity may involve some anaerobic activity, but it will necessarily stretch over an extended period of time and be completed primarily using aerobic metabolism. There may be brief bursts of high intensity effort as needed, and there may even be bursts of extreme effort for particular heavy lifting tasks, but on average the task will necessarily be completed with levels of effort that can be sustained over hours not minutes. We suggest that hauling out a buffalo carcass would not necessarily require a lot of glycogen, and even if it did, would not necessitate gorging on potatoes or other carb food to replenish glycogen stores. Perhaps the one situation outside of athletic competition that could force someone to put out maximum effort for as long as possible (and thus seriously deplete glycogen stores) is a fight (or flight) for life. These events presumably don’t occur in close succession, so the primary evolutionary adaptation would be to provide the capacity to sustain the necessary fight or flight long enough to survive the immediate crisis. An ability to fully recharge is not necessary and would not confer much less of a survival advantage.

In fact, it is often argued that the key characteristic of humans that makes them surprisingly competitive in the predator vs. prey world compared to animals that are nominally bigger, stronger, and faster is that humans don’t depend on their peak power output capabilities but instead on their ability to maintain lesser levels of output for very long times (as, for example, in a “persistence” hunt, where they literally outlast and outrun their nominally faster prey).

Other purported advantages of eating tubers cited in “Primal Potatoes, Part 2”:

1. Lower dietary protein/meat requirement, reducing the pressure for success in hunting large animals, and making it possible to feed more people (offspring) with each kill.

This seems to be a common misconception! Eating less carbohydrate means eating more fat, not more protein. And the hunting of large animals provides increased fat relative to smaller animal sources of protein. It is difficult to eat large amounts of protein, and most people find it almost impossible to eat too much protein. It is true, however, that tubers are easier to store for extended periods than meat (and meat fat) which must be more carefully prepared for long term storage, especially in warmer climates. Agriculture does enable more concentrated population centers and was probably a major driving force for the increasing urbanization of the world. However, it is not at all clear that the sort of monoculture version of agriculture that has come to dominate how we feed large populations is a positive step. In fact it is becoming increasingly recognized that we may be destroying the planet faster with mass agriculture than we ever did by overhunting.

2. Less burden on the liver for ammonia detoxification.

This is nonsense. Again, protein consumption tends to be self-limiting at levels well below anything that would present any significant burden to the liver (or kidneys).

3. Easier to avoid protein poisoning while at the same time maintaining greater glycogen stores.

Again nonsense. Protein poisoning is just not a serious risk. And it is not difficult to maintain more than adequate glycogen stores with very low carbohydrate consumption because glycogen stores do not need to be 100% full in order to provide adequate auxilliary anaerobic energy production.

4. Easier to maintain and increase lean mass in response to the stresses of high intensity activity, with a lower dietary protein requirement.

False! As anyone who has seriously tried a low-carbohydrate diet knows, it is much easier to maintain lean body mass without increasing excess fat storage if carbohydrates are minimized in favor of fats. And carbohydrate consumption always causes blood insulin levels to spike, which has a whole series of negative consequences. Arguably, from a public health point of view, the widespread adoption of higher-carbohydrate diets was the single worst event in human history that is the major cause of most of the so-called “diseases of civilization.” Building lean mass (muscle) is usually easier with adequate protein consumption. The key to maintaining it is to (1) make sure that you maintain sufficient nutrition so as not to catabolize too much of your own protein (which the body will do if other fuel sources are limited) and (2) to consume enough protein for muscle building and rebuilding/repair. (See for example http://www.bodybuilding.com/fun/md92.htm and references cited therein, which provides evidence that excessive carbohydrate consumption post-exercise actually inhibits optimal muscle growth and repair.)

5. Reduced pressure to hunt only the fattest animals by use of carbohydrate instead of fat to dilute the protein content of the diet; which greatly enlarges the pool of potential prey, increasing dramatically the amount of energy available for harvest.

Fat is good anyway! You should always be hunting for your fat needs as well as your protein needs. You just don’t need that much total protein. But you do need some protein, and high quality protein (i.e., the so called “essential” amino acids) is hard to get in sufficient quantity from non-animal sources.

In summary, while we certainly believe that humans likely ate tubers and other starchy vegetables (and eventually the New World potato) when they could be found, we see no evidence that that behavior conveyed any sort of evolutionary advantage beyond survival in times of limited food availability.

SF Marathon Part II: So why so much slower after 26 years?

2009-09-01T02:35:00.000-07:00

I was actually pretty happy with my performance, since my trail ultra times have been much slower, and I wasn’t too confident how I would hold up to all that pavement running. I was also very happy just to be able to do the event, grateful that my 53-year old body, despite its nagging aches and pains, is holding up as well as it is. But why am I slower than I was 26- 27 years ago? Well aging is the obvious excuse, but what does that mean, and is it in any way correctable? Does that mean I have less muscle mass, less strength to work with? Does that mean that my heart is weaker, or just slower? Does that mean my muscles and limbs have lost elasticity and/or I have reduced running economy now? Is my higher blood pressure putting too much load on my heart? Do I have endothelial dysfunction and the muscles are being starved (relatively) of the blood flow they need? Or can it all be attributed to increased weight?

I subsequently ran several other marathons during that time period: Summit Marathon- from Los Gatos to Soquel (across the Santa Cruz mountains, another 3:45 - it was tough!), Oakland and Avenue of the Giants. I tried (and failed) to qualify for Boston at Oakland (the qualifying time was 3:20 at the time, but my calf froze up so badly during the cold rain of that race that I had to back off the pace) for a 3:27. Avenue of the Giants was a 3:34, perhaps still overly cautious with the calf muscle. Still, I was at the point in my mid twenties where sub 3:30 was quite doable. I suppose the other piece of evidence I have is that a couple of years later, after starting grad school, I talked a bunch of other students into trying a marathon (Shamrock Marathon at Virginia Beach). I thought I had prepared much the same as before, training in the hills of Charlottesville, but only managed a 4:15. Maybe there was something magical about that early training on the Bay Area hills…

It’s possible that I stumbled upon a useful training program back in 1981-82, where my usual run was about 5.5 miles on some flat but also some pretty tough hills (the Dish loop). It’s possible that I was just lucky and managed to train hard enough without injury long enough to make good progress. It was all very intuitive- I just trained by how I felt on any given day. It’s possible that the bicycle commuting I did added some extra fitness. It’s all still a mystery to me. It’s also possible that I was still significantly undertrained if I wanted to know what my real potential could be. Given what I know about my training at the time in comparison with what I read about now, it seems that I should have been able to progress even further, perhaps to 3:15, maybe less, though I doubt that I had the potential to do much better than 3 hours.

A very rough calculation/guesstimate of my VO2max based on performances from my mid-twenties is 45 ml/min/kg (based on a 7:57 minute per mile marathon pace), with the caveats that 1) this is not the correct way to determine VO2max of course, 2) I could probably have gone at a faster pace had I trained better and not gotten injured, and 3) my VO2max in 2009 could be very different from my estimated VO2 max from 1983, but this is the best data I have at the moment. In other words, I haven’t sprung for a proper test, so this estimate will have to do for now. This number is not merely imagined, but is based on a chart in Noakes’ book "Lore of Running" where various paces are correlated with weight normalized VO2max values. Having a good VO2max is helpful in achieving good running performance, but it is well known that being able to sustain a higher percentage of your VO2max effort is more influential on running performance than VO2max itself. Superior running economy and other nebulous factors are also important in determining who is actually faster. Noakes discusses these quite a bit in his book. See also Lyle McDonald's post for more discussion about predictors of endurance performance, and VO2 max in particular, or the extensive writings on Alan Couzen's blog .

A correlation to of this VO2max chart with marathon paces to my current values would look something like this: as of race day, I weighed about 144* lbs (65.5 kg); in my marathon running mid-twenties I (think I) weighed about 125 lbs (56.8 kg). Assuming nothing else fundamental has changed, in absolute terms, I should have the heart and lungs and leg muscles etc for a VO2max of 2556.8 ml/min (multiplying by the 56.8 kg). Dividing by my now increased mass, that yields a VO2max of 39.0 ml/min/kg and a predicted marathon pace of 9:08 per mile, or about 4 hours. This happens to be closer to my predicted Yasso 800 marathon time of 4:10 than what I actually did in July (4:31), but still seems to indicate I should be able to do close to a 4 hour marathon if the only adjustment to VO2max was added weight. My 2009 performance (10:13 minute per mile marathon pace) would suggest a VO2max of ~34 ml/min/kg. Maybe this wasn’t a best effort due to not being able to stretch out a bit more in the first half, and also by the fact that I had no muscle soreness the days after, that would seem to suggest I didn’t push the pace as much as I maybe could have. Of course, VO2max doesn’t tell the whole story- there are many accounts of people being faster without having a higher VO2max. It’s also possible that I have less lung capacity due to past bouts with pneumonia- the x-rays do show some scarring.

Of course the most likely explanation is that I’m just poorly trained/more cautious now. According to “Hadd’s Take on Distance Training” (skip ahead to part 6 if you want to see how to calculate marathon heart rate (HR) and training HR), marathon HR should be 15 – 20 bpm slower than max HR. In other words, if properly trained and motivated, you should be able to maintain an effort for marathon distance at 15 – 20 bpm slower than max HR, but it shouldn’t feel uncomfortable. According to this calculation, my marathon HR should be more like 155 than 145. That HR for me right now translates into about a 9:00 – 9:10 pace- much closer to the Yasso 800 predicted time, and in good agreement with my estimates from VO2max calculations, but still pretty difficult to maintain.

So why didn’t I run nearer 155? Good question, don’t really know. Some of it is a sense of cautiousness, that I maybe shouldn’t overstress myself, at least not pushing too much. Running at a HR of 155 feels pretty hard to me these days- it’s not hard enough to be reduced to frantic panting, but it feels too hard to maintain for more than a few miles. Perhaps I need to follow more of Hadd’s suggested training and develop my aerobic potential as far as I can and then see how it goes. It’s surprisingly hard to do though- the natural inclination is to run at a pace that feels good- that pace tends to be slightly anaerobic though, especially when rested and feeling good, but not really sustainable for miles and miles.

Another posting on Chuckie V’s site addresses this further. This post basically says that lots of mileage is what makes for superior runners, and points out that the qualifying times for Boston have been eased up over the years because people are training differently, relying on “quality” higher intensity workouts rather than higher mileage. Alan Couzens also addressed this recently, pointing out that research supports the idea that aerobic adaptation in slow twitch fibers is linear with increasing exercise stimulus, suggesting that easier training for several hours per day could provide further increases in training effectiveness. This is not true for threshold/”high intensity” training, the improvements from which maxed out in some studies at about 1 hour. The good news is that you don’t have to kill yourself with exhausting stressful training to see the benefit, and it also accrues over years, even decades! Of course, there is a place for higher intensity training, to increase lactate threshold and sharpen up your speed, or for fun. Anyone who runs on hilly terrain can hardly avoid some higher intensity work on occasion anyway, but the bulk of the training does not have to be “hard.” This training philosophy is not currently fashionable, and I may not be able to manage much more mileage than I currently do anyway (40-65 miles per week), but I can try.

There is a pretty clear correlation of age with heart rate, and it seems that a slowed heart rate should have an effect on my slower performance as well. At this point it’s hard to know since I don’t know what HR numbers I was dealing with in my youth (though I'm sure they were much higher than now), and since my resting HR (and max HR) keeps dropping now. But according to the calculation above, the real limitation resulting in my slower performance is my excess weight, i.e., if I could maintain my marathon HR (a big IF) I would perform at a level that is scaled down by my greater mass. So theoretically, if I lost down to 125 lbs again, I should be able to perform as well as I could in my twenties? This seems unlikely, but worth the experiment. I’ll keep working on it.

*Currently at 139! Yea!

SF Marathon Part I: SF Marathon Revisited

2009-08-04T23:58:00.000-07:00

As a birthday present to myself, I decided to run the SF Marathon again after 27 years. This race has a special place in my heart since it was the first marathon I ever ran (back in 1982!), and because it was such a wonderful experience then. I thought if I really wanted to judge my fitness now, I should try it again so I can compare the then with the now. But first, let’s talk about why it was so wonderful back in 1982.

In July of 1982, I had only been running regularly for about 10 months. I had been a sprinter in high school and early college, and then crewed for Duke and Stanford, all of which are largely strength/fast twitch or strength/endurance sports. I always hated the two mile timed runs we had to do for crew to judge our fitness, just as I had always hated the warm up for sprint practice. But when I went through some big hiccups in my personal life, I coped with the emotional trauma by running long and hard, mostly at the Dish loop at Stanford, which was convenient because I worked as a research assistant there after graduating from college. I also ran some with friends, most of whom were faster than me. One was running the SF marathon, and I went along as an unofficial runner at the last minute. I didn’t know how to train, and hadn’t in fact done much specifically to train. I had obviously done some longer runs- maybe 8-12 miles, and the weekend before the race, I went out for ~18 miles on the roads from Stanford out through Portola Valley and back. That went ok so I decided I was ready to try the distance. But I was certainly not expecting much, and just hoping to finish. My running partner went out fast and I didn’t expect to see him again until the finish. I sauntered along for a few miles at what felt like a very slow pace. After ducking into a restaurant to use their bathroom (no portapotties at this event!), I figured it was time to see what would happen if I sped up, so I slowly increased the effort level and kept on speeding up until I couldn’t anymore. This worked surprisingly well, and before I knew it, I was steadily passing people, including my running partner (reduced to a painful walk by that stage)! I don’t know why it worked so well (this is all relative of course- real speedy people will laugh at my pitiful accomplishment), but I was thrilled to finish in 3:45, and especially to pass the guy who always made me feel so slow. I still have the medal to this day, which they gave me even though I was an unofficial runner.

So on to 2009. I’ve been running pretty regularly, albeit with injuries of one sort or another for the past year. Last summer it was a piriformis problem, and this past winter, it was hip flexor tightness, along with more piriformis and glut medius problems (opposite hip this time), not to mention sore gluts and hamstrings when I finally got other parts working properly. In trail ultras, there can be a fair amount of hiking due to steep hills and rough terrain, and trails are rough enough that speed isn’t really an option (for me anyway), so these injuries were not debilitating. More recently, I’ve managed to get past those particular problems, and train more or less regularly, and work on pace as well. So I thought it might be time for a comparison with those earlier days. Also, after David injured his knee last May (he’s mostly recovered and faster than before it seems!), I did more road running, starting from home running alone and heading up into the hills, or up to the Dish, while still doing trails some of the time. My usual training was pretty slow, with easy efforts at relatively low average heart rates (~130’s- I can be very lazy, but justify this by saying that it is low stress :) ). I threw in some faster tempo runs and Yasso 800’s starting in June to help raise lactate threshold, and these predicted a marathon time of ~4:10. So I felt like my legs and feet were reasonably acclimated to pavement and my conditioning should be good enough to get me through a marathon in a not too disappointing time.

The Expo: I’ve only done trail races since starting to run and/or train (if what I do can be called training) more consistently in the past year. So the Expo was a first for me and I was eager to see what it was all about. There were lots of samples of drinks and snacks to try, and clothes that looked like fun. But all I bought was shoes- there was a $50 per pair bargain booth, and I got my first Mizunos and a pair of Brooks. I don’t have much in the way of road running shoes (I ran the race in a cheap pair of Adidas from Costco!), so I thought this would be a good plan. We’ll have to see how these shoes work out.

On race morning, David dropped me off a few blocks from the start with only minutes to spare from my wave 6 start time of 6:17. The line for the portapotties was so long, I just gave up and headed to the start. This probably explains the unexpected mix of running speeds in the pack- all those faster people who were delayed for half an hour at the start! Our wave began, and I loped along at about a 10 minute pace, hoping things would thin out soon so I could get up a little more speed. That never really happened though. The pack was very thick all the way out and back across the Golden Gate Bridge. People could never really get their stride due to bobbing and weaving between faster and slower people all the way up to about mile 10. I blame this partly on the portapotty situation at the start, but also we really needed more space! Many people were taking walking breaks, which made it hard for those of us trying to keep a consistent pace. I felt great though, light on my feet (unusual!)- nothing like adrenaline and a crowd of happy people running in cool SF fog! Returning across the bridge, I yelled a loud “Go Julianne” to Julianne , the only other person I knew who was running (she was pacing the 4:45 group). When they offered Gu at the aid station, I obliged and had a couple (the caffeine was a good idea for this night person), downing them somewhere between miles 8 and 13. There was more Gu at mile 16, and I took another. All during this time, my heart rate was running about 145. It rose on the hills, but apparently I made up for any increase on the downhills. I felt like I was fading a bit between miles 13 and 16, but soon thereafter (maybe it was the double caffeinated espresso gel!) realized that if I was going to have any hope of a strong second half, I’d better get moving. I pushed into a heart rate zone of 150+ through Golden Gate Park and down toward the Embarcadero again. I kept pushing and pushing, but unfortunately, there were plenty of hills that kept pushing back. Then there were the diversions- it was very disconcerting to arrive at an intersection and have them pull caution tape right in front of you and send you a different way! Presumably, this trick allowed them to keep some traffic moving across the race route. I still felt ok though, except for cramping calves. The cramping got bad enough that I had to stop and walk a few times, or pull over to the curb and stretch out my legs- they were very very stiff! I met an older man during one of my stretching interludes who seemed concerned I might quit (he was 71, so I can still say he was older, right? ). He was wearing a complicated looking knee brace. When I asked him what the brace was for, he explained that he had arthritis and when his Dr. said he couldn’t run anymore, he said that was not an option. He said his knee actually feels better after he runs! He also explained that he runs at a level of effort to keep his heart rate below 130 (must be nice!). We ran together for a bit, then I went on ahead while I could, trying to get mine back up to 150 or so. Of course, the last few miles of a marathon just suck no matter what- everything was stiff and hurting by that point and I could barely climb up and down over curbs! And it was warming up in the now sunny city! But drag into the finish I did, in a sparkling 4:31!

The post-race food was disappointing, and not on par with post-ultra refeedings. There was carbs and more carbs in the form of bananas, snacks and more sugary drinks, but nothing more substantial, not that I saw anyway. They were very eager to replace our glycogen stores the moment we stopped running, but I wasn’t eager to replace my glycogen stores immediately- I planned on taking at least one rest day to recuperate. It’s not like a multi-day event where you need to be diligent about getting fuel stores replenished right away. After a grueling event as long as a marathon, you need protein to start the process of rebuilding and repairing muscles, not empty carbs! See the very interesting posts by Robb Wolf here and here. We left the food behind quickly, as there was really nothing there of any use to me. We found a gyro place instead, where at least there was mix of protein, veggies and carbs. It was hard to leave behind the massage tables though. They were quite tempting! Fortunately, David gives a good massage too, and I enjoyed his generosity very much once we got home.

I also thought it was interesting that they put water or cytomax into tiny little cups, holding usually no more than 2 ounces! After the race, I was very thirsty and drank the entire bottle of water they handed out at the end almost immediately. Do you suppose they were concerned about hyponatremia, and trying to keep people from over-hydrating?

I made no effort to “Carb-load” for the race. I may have eaten slightly more carbs than usual (maybe 150 g vs 100 g?), but nothing dramatic. The night before, we had plenty of protein and veggies, but also some birthday cake (a spectacular nut torte made by my in-laws). I was pretty happy that there was no outright crash into the “wall” and in fact I felt quite strong through the usual “wall” territory. Whether this was because I used a few gels (75 g worth of carbs), ample caffeine, or pacing so that I burned plenty of fat and didn’t prematurely deplete my glycogen stores, I don’t really know. I never used gels (they didn’t exist!) back in the 80’s when I was faster, and barely drank any of the Gatorade they offered at water stops anyway. Marathons just aren’t that long, and with proper training, you shouldn’t need carb supplementation anyway. But that’s not fashionable now either. Still, I try to keep an open mind and test these theories as best I can.

I wore drymax socks, and despite no blisters on the left foot, ended up with 3 on the right! The odd thing is that these blisters were in different places than I’ve ever had them before. I think an important part of blister avoidance is acclimating the feet to both the shoes you’ll be running in and the running conditions. I could have had tougher skin on those parts of my feet if I’d trained more in those particular shoes and with longer runs on those types of roads. Since I put in only a few longer runs on roads at all, and often in different shoes, my feet just weren’t prepared for the particular stresses of that event. You’d think I would know this by now. Well, live and learn, maybe…

Surprisingly, the Garmin says I averaged a heart rate (HR) of 147 for the first half (at a pace of 10:05) and 145 for the second (at 10:20). All the effort to get the HR up didn’t do much to increase speed overall, but perhaps the problem was the cramping and the heat due to the warming city streets. I certainly tried to pick up the pace, but the hills between miles 15 and 21 made sure the effort went largely to making it up and over them, not speediness. I don’t really think I could have gone much faster, except maybe in the earlier miles if there had been less crowding. By the end, I was pretty beat and going on inertia and will power.

I knew going into the event that I would probably be disappointed, and it was not likely I would have another surprisingly fast run. I wondered if maybe I hadn’t trained adequately, since I ran considerably slower than I had hoped. I mean the Yasso 800’s predicted a 4:10 after all! Perhaps they’re not so accurate. On the other hand, where was the muscle soreness? I had none of the usual post-race muscle soreness! Walking up and down stairs was just normal the days after the race. My body acted as if this was just a hard training run, and I went running again after resting only one day! This argues the effort was not all out. Perhaps I’m too used to ultras and doling the energy out more evenly over a longer period of time. Then there is that laziness factor…

All in all, this was a nice event. There were cute signs all along the race course asking questions about SF history (but it would have been nice to see some answers to those questions too). I saw parts of Golden Gate Park that I didn't even know existed before. The music stations were enjoyable too, if spaced a bit far apart. It was just a nice place to run on a foggy morning with 20,000 other like-minded people.

That said, I think trail ultras are a lot easier, at least for me. There is more variability in the terrain, allowing you to use different gaits, paces and muscles depending on what the trails throw at you at any given moment. At my level, I walk some, stretch more and generally don’t get quite as stiff and depleted as in a road marathon. So more trail ultras are in the plans, but possibly another road marathon. I should be able to run one faster, shouldn’t I? (see Part II, coming up)

Diablo Redux

2009-07-13T07:42:00.000-07:00

Getting behind in blogging here… After the pains from Quicksilver had worn off, I noticed that PCTR was holding another event at Diablo on June 6th. Not one to leave well enough alone, I watched the weather forecast, and when it was clear we were in for great running weather that weekend (i.e., unseasonably cool even for the Bay area), I signed up for another round of torture in the Diablo 50K!

This was one event I had to do completely solo because David hurt his knee—he hurt it sprinting on the track of all places. That’s what we get for throwing in a little high intensity training! He was having enough trouble just walking, so asking him to run any race was out of the question, and he wasn’t willing to come along as my chauffeur or crew (I can’t imagine why).

Anyone who’s interested in trail running in the Bay Area knows about Mt. Diablo. The PCTR 25K event makes a single ascent of Diablo, totaling 4,450ft ascent (and descent); the 50K event repeats the loop, totaling 8,900 ft ascent. Having opted for the latter, I can say that 25K was really quite enough!

We started out on a similar course to the Diablo 50-mile , but avoided Mitchell Rock and Eagle Peak, opting instead for Back Creek and Meridian Ridge Rd. and then joining Deer Flat Road. From there to Juniper Campground Aid station was the same—just a long climb up the fireroad (with the exception of one steep downhill where you are tortured by having to regain all that elevation you just lost). I had fun chatting with Dianne Forrest (who I met at Headlands 50K, my inaugural ultra), and with Jo Lynn’s friends Christy and Theresa. The leaders and speediest folks passed us going back down the hill at this point (about 90 minutes in!). Since this race is part of the Sportiva Mountain Cup series, there was money waiting for the winner of the series, and some really fast folks were contending this day! I recognized Chikara Omine (who I had met at Quicksilver) moving well (he would come in 4th overall) and already on his way down!

Arriving at the aid station at Juniper, the folks kindly filled bottles and offered us snacks and sent us on our way. The next section routed us out along the Summit Trail, with some gentle ups and downs and beautiful views of the Bay, Walnut Creek, Oakland (pretty much everything actually), until we encountered the rest of the real climbing. Along this section of beautiful single track, we encountered more fast runners flying back down the trail like gazelles. Definitely tricky on such a narrow trail! I recognized a few more faces, like Caitlin Smith and Mark Tanaka. The last couple of miles got really tough though. You could see the tower through the mist at the summit for a long time before it seemed to even get any closer. We just kept climbing and climbing, getting more and more tired, and then finally came out into the parking area at the summit, with its incongruous cars and bicycles and blissfully ignorant persons looking at us like we were from another planet. I don’t know if the bicyclists were impressed at us for hiking the whole way up the mountain or not, but all I could think about was how they were going to coast effortlessly down the mountain, while I had to kill my quads to get back down, working even harder than on the way up!

The view from the top was breathtaking as usual, even with the wisps of cloud hovering around the summit. After a quick breather and stretch at the top of the tower (and taking a picture of Christy), we turned to begin the long climb down. The tricky footing and steep descent was challenging, but very fun! I’ve been pushing the downhill pace this spring, since recovering from piriformis injuries that I had last year this time, and gaining confidence in my balance, agility and hip muscles. The trail included some climbs just to remind us of how much fun we had on the initial climb up. Finally, arriving back at Juniper aid station, we refueled and prepared for the long fireroad descent. I tried my best to make up time here, and eventually worked up enough speed to slip and slide past a few people. It was great fun running down the fireroad, skating on the loose gravel and using the slide to cushion the descent. I am not a fast runner, but I did my best to get the pace down below 8 min miles and keep it there as long as I could. This was enough to get me ahead of a few people, and I came into the 25K aid station/finish area in about 4 hours.

At this point I was seriously hot because of working hard and running in the sunbaked canyons along Mitchell Fire Road, which were not cooled as effectively by the breeze as the heights. I hung around about 10 minutes cooling off, drinking coke on ice (so good in races I have to admit, though I never drink it when not racing!) and hoping some other 50K runner would come in so we could go out together. After a little while, I realized this was not going to happen and I’d better get moving. So I headed back out, climbing the #%$@ mountain again alone!

This time, the ascent was slower. Toward the top of the first leg of the climb, just before reaching Deer Flat Road, I realized my right calf muscle was aching. With another 1000 ft of climb to go, I had to slow down even more to favor it, making the quads and gluts do the lion’s share of the work. The third time through at Juniper, the aid station volunteer accused me of leaving after cutoff time and didn’t help me on my way at all! Just what I needed—demoralizing comments! I continued on anyway after correcting him and fending for myself, and met a number of other 50K runners on the way down from their second visits to the summit. In contrast, they were all encouraging and enthusiastic, and lifted my spirits.

One more time back the way we came…I was feeling pretty lonely, but the weather was nice, the day was beautiful and there really was no problem except for the now grumbling calf muscle. I made it back through the aid station one last time, and made decent speed back down the fire road and toward the finish. Not so fast this time around, but good considering. I managed to catch up to one runner about a half mile before the finish. He was walking, so I stopped to walk with him and ask how he was doing. He was feeling pretty beat up and demoralized at this point. We chatted a bit and soon I broke into a jog again, and he came along with me. When he stopped to walk again, I stopped to keep him company. This happened a couple of times and then when we were approaching the finish, he took off running fast again! I could have tried to sprint past him, but that seemed absurd (the last two runners sprinting for the finish!), so I came in a few seconds behind him. I was really hoping not to DFL this event, but due to my stopping to check on a fellow runner, I got to DFL anyway!

This raises a running etiquette question: if you happen upon someone in a race who is obviously flagging, should you just blow by them (assuming you are feeling strong at the moment) and let them deal with their problems on their own, be it injury or just being tired? Or should you slow down to check on the runner’s status and offer help and encouragement if needed? And if you are the flagging runner, should you show your appreciation for the other’s concern by speeding up and blowing past them once you get your legs back or see the finish line? Or do you bring it into the finish together, so that neither one gets left behind?

Maybe this is just a girl thing, but I would have thought showing a little bit of concern warranted being shown some tiny amount of appreciation! (He did thank me afterwards, but that did not make me feel better!) This is not the first time this has happened to me either!

The aftermath and lessons learned:

The day never became warm up on the mountain, and the breeze was strong- it was truly a glorious day to revisit Diablo, even though it is a hard mountain in any weather!

For nutrition, I enjoyed coke on ice, a few potato chips, cytomax, a quarter PB&J sandwich and 3 gels. I also supplemented the dearth of protein by eating a piece of ham (a little too salty, but it might be just right on a very hot day). Again, not very much food. I don’t really know that taking in carbs early in the event was helpful. We’d have to measure blood glucose levels and insulin levels to really know what was happening. I can say that after a recent 12 mile run drinking nothing but water, my blood glucose was up at 123 mg/ml—certainly not hypoglycemic! Actually this is in line with what we would expect, since adrenaline causes the liver to release its stored glycogen to pump up the blood glucose levels, and 12 hilly miles isn’t nearly enough to deplete total body glycogen. It’s possible that for me at least, taking in carbs early in an event is counterproductive (promoting insulin release and inhibiting fat burning), or at the very least unnecessary. It doesn’t seem to help maintain my energy levels all that much, since typically after about 4 hours of slogging up and down steep hills, I’m tired anyway. I either need a whole lot more than I’m getting, or something else entirely (perhaps protein instead). In my past days of running marathons, I never supplemented with anything at all, and didn’t feel any need for it. So perhaps the current obsession with gels and carb supplemented drinks is really all about creating a market and not about health and performance. I will just have to keep experimenting to find out what works best, or at least better.

I gave my muscles 3 days to recover before trying to run again. The quads were definitely quite sore from all the ups and especially the downs! I went out after the 3 days of rest and felt better than ever.

The sore calf made its presence known for a few weeks, particularly if I tried to run faster, and complained about how it had barely avoided injury and berated me for my mistreatment. I had to massage it quite a bit and intentionally decrease the kick-off phase of my stride (slow down more) so as to let it to rest a little more for a couple of weeks.

The foot injured at Quicksilver a few weeks before held up ok, though it still hurts occasionally.

Only one blister—on the top of my foot where it was pressing against the laces during the downhill stretches! The thick calluses on the balls of my feet were fine though definitely warm, and one of them peeled completely off (but the skin underneath was also calloused!) so there was no injury. Again, I think Drymax socks really help (I also used vasoline as a lubricant).

I am still lousy on steep uphills. I’m just not a very good powerwalker, and not strong enough to run them either, though my gluts (and later one calf) were screaming that I was working them too hard. I guess Diablo still kicks my butt!

Vibram Five-Fingers Shoes and “Barefoot” Running

2009-07-04T13:04:00.000-07:00

I have always been something of a maverick with regard to sports equipment, resisting the latest gear marketing efforts in favor of minimalist and homemade equipment whenever it seemed to make sense. I also look for what actually works for me instead of what the pundits tell me I must have to optimize my performance and protect me from injury.

For example, I’ve been riding a recumbent bicycle for more than 25 years now, one with handlebars under the seat. Before I adopted the recumbent riding posture, I would routinely pinch nerves in my hands holding onto conventional handlebars. For rides of more than a few miles (I did a lot of longer rides of 50 to 100 miles or more in those days, as well as some extended multi-day trips), I would end up with numb hands. Since manual dexterity is important, this was unacceptable, and the recumbent riding posture fixed the problem. I also feel safer on a recumbent bicycle, largely because, if I fall off, I am much less likely to go head first over the handlebars. There is a visibility issue in that I ride lower to the ground, but that is readily fixed with a flag.

I also often find myself choosing footwear that is intended for some other purpose than the one I'm using it for. When I moved to the San Francisco Bay Area and continued to participate in orienteering, I found that even shoes that were allegedly specially made for orienteering did not work very well in the Bay Area hills, where I often found myself contouring along steep hillsides that could be anything from soft mud to loose dirt and rock. I abandoned my special orienteering shoes in favor of some cheap football shoes that had wraparound cleats that provided much surer footing.

My primary sport right now is trail running. There is, of course, huge amounts of hype supported by lots of allegedly “scientific” research that has created an ever-changing array of running shoes with all kinds of “features” based mostly around various allegedly needed forms of support and/or cushioning. “Trail running” or “all terrain” shoes have mostly tended to be shoes with a fair amount of both support and cushioning as well as deep treads for all the apparently obvious reasons. At the same time, serious racers on trails have tended to opt for lighter weight “racing flats,” at least for competition, just as for road and track running; they want to minimize the weight of the shoes. I, too, have found myself migrating toward lighter and lighter shoes with less cushioning. Most people in the business of selling you shoes will insist that it is dangerous to continue running in shoes after the cushioning has started to deteriorate (usually deemed to be a few hundred miles or a few months). I’m the kind of guy who thinks his shoes are just getting broken in at that point! And I never missed the cushioning beyond the occasional minor bruise if I step too hard on a small sharp rock. I’ve done all my recent ultra-marathon running in well-worn New Balance 790s. These are lightweight shoes with minimal support and cushioning, and the cushioning they do have tends to break down after a few hundred miles, well before I’m ready to replace the shoes. I’ve never had any foot problems with them beyond some toenail bruising on long downhill running. (I should note that I grew up wearing arch-support shoes to “correct” my flat feet. I still have very low arches and a tendency to pronate, but I’ve never sprained an ankle or otherwise had problems that I could attribute to the low arches, and I haven’t used arch supports in more than 30 years now.)

I’m also a fan of going barefoot. I rarely wear shoes around the house. I haven’t generally chosen to run barefoot, except on sand, though my feet are tough enough to withstand a few miles of barefoot pavement running. So I was intrigued when I encountered the Vibram Five-Fingers shoes. They were originally developed for water sports, but have been increasingly adopted by advocates of barefoot running. On something of a whim, I decided to try a pair. I’ve had them for a couple of months now, and they have become my primary running shoes!

There have always been a few people out there who have developed tough enough feet to go barefoot in all but the most dangerous conditions. A few have run marathons barefoot. But most of us non-bushmen haven’t got enough callouses to manage, say, a marathon without at least some protection. The five-fingers shoes can provide that protection and give us a chance to get a lot closer to true barefoot running under more ground conditions and run lengths.

Others have written more than I can about why you might want to run barefoot. There are links you can follow from the Vibram website. Check out Barefoot Ted and the Pose running method, for example. (And read Christopher McDougall’s new book, Born to Run, A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen, a surprisingly great read, that has quite a lot to say about running footwear [and Barefoot Ted]!) I’ll just focus on my recent personal experience.

I guess this still represents something of a preliminary report. Shortly after I acquired the shoes, I injured my Popliteus muscle, and have only just gotten back to where I can run my usual 40 to 50 miles per week, so I still haven’t got a lot of miles on my Five-Fingers. In some ways, though, the enforced slow recovery gave me a convenient opportunity to learn how best to take advantage of the Five-Fingers. Some observations:

1. If you’re going to be a “barefoot runner,” you are naturally tempted to forgo socks altogether with your Five-Fingers. I’ve now experimented quite a bit with and without socks. My current preference is to use socks only for hotter temperatures and runs of more than an hour or so. I don’t bother with socks for runs of an hour or less. The primary issue is that I start to develop hot spots after my feet start to sweat significantly. Socks help reduce the chafing and wick away the sweat. I don’t seem to need very much sock; I use very thin Injinji “liner” socks made from bamboo fiber, and I’ve had good luck up to the maximum run of about 16 rough trail miles I’ve tried so far. I did get a blister on the bottom of one heel on a hot hilly 8-mile run early on when I wasn’t wearing socks (and was still running with a heel-strike gait). Of course, if you’re not wearing socks, then the shoes are absorbing the sweat and dirt that normally ends up in the socks. I rinse the dirt and sweat out of the shoes every few days, something that I practically never do with “normal” shoes. Keeping the insole surfaces clean is important to minimize wear on the feet.

2. Five-Fingers shoes have a very smooth sole made of what I assume is a tough urethane material. (Vibram built their business around making tough long-lasting soles for hiking shoes and work boots.) So far, the soles show very little sign of wear, even though I’ve been doing relatively a lot of pavement running. I was concerned about traction, given the complete lack of tread, but I haven’t found it to be much of an issue. They slip a little on the typical summer dust on Bay Area dirt trails, but so do shoes with lots of tread. What you gain with toe grip generally makes up for the loss of tread grip. The shoes work fine in soft mud. Probably the most difficult terrain is tall grass and similar field conditions. The grass tends to get between the toes and get stuck. And, of course, anything spiny like star thistle can be a real problem. You wouldn’t want to run through a field of star thistle, cactus, or blackberries (not that I make a habit of doing so in any footwear…).

3. You do need to pay attention to where you put your feet. The soles spread the pressure points of ground features enough to dampen out the effects of fine and course gravel, but they don’t help all that much for isolated sharp rocks. I was already accustomed to sub-consciously paying attention to foot placement anyway, since I haven’t been using shoes with much cushioning for a long time, so I have yet to actually bruise my foot. If anything, the minimal cushioning really does force you to be more in tune with the surface you are running on. But extended running on rough trail does tend to abuse the feet somewhat more than running in shoes with more cushioning. Part of the adaptation one makes to running in Five Fingers shoes is to develop the foot muscles more to take advantage of the new-found capability to “feel” the ground you’re running on, and you can then adapt to longer running on rougher trails.

4. There is no fundamental requirement that you change your running gait to use Five Fingers shoes. However, the absence of heel cushioning certainly encourages a switch to something more like “Pose” running, where you land first on the ball of your foot rather than the heel. It’s a big enough change for distance running, that I didn’t do it immediately. But having made the transition, I really like what it does for me. It significantly reduced the stress on my injured knee, and it has probably given me a bit more spring
in my step and some resulting speed. Surprisingly, to watch me run, you might not even notice the difference. I already tended to land nearly level-footed, so the change is fairly subtle to a casual observer. I still land nearly level-footed, but tipped slightly the other way. From a muscle training point of view, it was necessary to develop a little more strength in the calf muscles, since they now play more of a role in absorbing the impact of each footfall, but that didn't take very long (for me, at least).

5. So far, my Five-Fingers are showing very few signs of wear and tear, though my total experience is probably still under 200 miles or so. One strap started to fray (possibly due to a manufacturing “defect” where the slot that the strap goes through was a bit too sharp), and I added a small piece of leather to repair the strap and take the wear. I don’t yet know what the ultimate failure mode that will cause me to retire the shoes is likely to be.

6. I haven’t yet worked up to runs of much more than a couple of hours, so I don’t yet know what issues will come up. So far, though, I’m not seeing any likely limitations, and I’m hoping that my chronic struggles with toenail bruising on multi-hour runs will be a thing of the past.

David

In Praise of the Little Muscles

2009-06-22T16:21:00.000-07:00

The more I learn about how animal bodies achieve motion, the more impressed I am by the mechanical engineering that has been achieved by Mother Nature through some millions of years of evolution. Prosthetic limbs and robot arms that have been built to date by humans can’t come close to duplicating Nature’s exquisite designs. For example, I recently saw the latest personal robotics research coming out of Willow Garage. They’re doing interesting work, though as someone who has watched robotics research from the sidelines for 30 years or so, it’s clear that real progress is still slow, and we’re still a long way from giving Nature any serious competition, either from a physical performance point of view or from a computational intelligence point of view.

As someone who has never really studied anatomy in any detail, I also never fully appreciated just how many muscles are engaged in simple motions, what it takes to use and control them properly, and just how important some of those little muscles that we tend to ignore can be. There’s nothing like an injury to a minor muscle to teach you what their importance and function are.

My first experience with a “minor” muscle injury was some years ago. I tore my right piriformis muscle doing a lunge while fencing. (Look up all the muscles mentioned here at Get Body Smart.)

The Piriformis is a little muscle under the Gluteus Maximus that is used for leg rotation at the hip. I knew I’d done something bad at the time, but I didn’t have much in the way of acute pain and mostly just ignored the injury. Some months later I was experiencing chronic but vague hip discomfort and a sense of looseness in the joint. A good physical therapist was able to diagnose the problem from my assortment of vague symptoms, and having diagnosed the problem (the muscle at that point was seriously knotted), it was a straightforward, if slow, process to undo the damage and get the muscle back to normal function.

Apparently, there aren’t a lot of nerves in these small muscles compared to the major skeletal power muscles, and one can’t necessarily feel the damage unless you find the muscle and start to really knead it—something that can be hard to do for a muscle that is hidden behind something much bigger. It took a year or so of regular rubbing (the corner of a countertop or table
worked great!) before the muscle stopped acting up from time to time.

I had a similar experience with the upper part of my right Soleus muscle. In that case the injured muscle was hidden underneath the big calf muscle (the Gastrocnemius). The Soleus contributes to flexing the foot, and thus is commonly stressed by running.

Again, I was experiencing vague calf pain while not having any obvious pain in the big muscles. Once identified, Soleus muscle damage can be easily massaged by lying on one’s back and resting the lower leg on the opposite bent knee. Move the lower leg back and forth over the knee with the Gastrocnemius fully relaxed, and you should easily be able to find any tender or knotted
areas. Even though I don’t have any particular damage problems with this muscle now, I still find it a useful post-run massage to do—the Soleus muscles often take a beating on a long hard run. Also, while I generally subscribe to the theory that warming up slowly is far more important than stretching (which can be downright counter productive, promoting rather than preventing injury), I do find it useful to stretch the Soleus muscles by flexing the foot up with the leg straight (which also stretches the Achilles tendon and attached structures).

My most recent experience was the most dramatic yet. It introduced me to yet another lesser-known muscle that I had been completely unaware of and left me unable to run for several weeks! After running many hundreds of trail miles over rough terrain with little more than routine sore muscles and the occasional minor bumps and scrapes, I managed to injure myself on the track! I was well warmed up and had just run a 7-minute mile (about as fast as I can go for that distance). After a lap or two of cooling down, I decided to sprint for 100 m or so. Mistake! I almost never really sprint, and I don’t really have well-developed sprinting muscles and technique. Again, I knew I’d hurt something, but I wasn’t quite sure what. A couple of days later, about seven miles into a twelve-mile trail run, I landed slightly wrong on the injured leg going downhill, and felt a sharp pain in my knee. After the acute pain subsided, I was suddenly unable to run at all, though I could still walk with minimal limping and was able to walk the rest of the way.

It turns out that the damaged muscle this time was the Popliteus. (And no, there was not any ligament or cartilage damage at this point.) This seeming unimportant muscle is located immediately behind the knee running diagonally across the leg from the outside (at the top) underneath the top of the Grastocnemius muscle. It’s pretty hard to find even when acutely injured, but it can be massaged (carefully! there are other sensitive structures nearby) if the Gastrocnemius is fully relaxed. The Popliteus muscle serves at least three important functions. First, though it has very little power being very small, it is the first muscle that fires when you bend your knee from a fully-extended position. Second, it helps hold the knee joint together. Third, it helps prevent you from “hyperextending” your knee (going past the normal maximum extension—straight leg). Lacking a normally functioning Popliteus muscle is surprising debilitating! The knee joint just doesn’t work right. Most joint motions involve multiple muscles that are fired in an exquisitely timed sequence to achieve the full action. The Popliteus fires first
for knee bending, and without it, your timing falls apart. The joint looseness and potential for hyperextension leave the joint cartilage vulnerable. My attempts to continue at least light running caused acute pain to develop at the medial meniscus, the main piece of cartilage padding the knee joint on the inside. The weak Popliteus muscle allowed excessive pinching of the
cartilage, especially on impact. In effect, the Popliteus muscle also plays a key role in the sequence of muscle firing that provides shock absorption as you land on your foot when running. This particular problem is peculiar to running; walking and bicycling were possible with little or no pain. (With most knee injuries, bicycling is painful, since it tends to put significant stress on the knee.) Of course, as with any injury, any limping or other change of gait, whether conscious or not, tends to stress other muscles that are compensating for the injured muscle in unusual ways. In this case, I got quite sore in the adductors in the opposite leg!

The good news is that, while recovery has been slow and I was unable to run much at all for a few weeks, no lasting damage occurred. I walked and bicycled more, and eased back into running with shorter, slower distances, being particularly cautious on the downhills. Ibuprofen and a simple knee brace also helped enable a little more activity sooner, and I managed not to lose too much conditioning. I also followed the recommendation to take a Glucosamine/Chondroitin supplement.

I also took advantage of the slower shorter distances to start to switch over to more “toe” running (landing on the ball of the foot rather than the heel). This reduced the impact on the medial meniscus, again allowing me to run more sooner, though it has required developing a slightly different set of running muscles. (You use parts of your Gastrocnemius muscles more for shock absorption when landing on the ball of your foot than you do when landing on your heel.) I’ve been experimenting with Vibram Five-Finger shoes, which I like a lot for running, and since these shoes have no padding whatsoever, landing on your heels
is not such a good idea, at least on rough surfaces, so I was already motivated to change my running style. But I’ll postpone a detailed report on these unusual shoes for another post.

Final notes: (1) If you’re wondering whether the new shoes caused or exacerbated the injury (I was wearing them when it happened), I can’t prove definitively that they didn’t, but I’m pretty convinced that there’s no connection. I’ve tried various shoes since and keep coming back the the Five Fingers as the shoes that cause the least stress post-injury, which is certainly suggestive that they couldn't have caused the injury in the first place. (2) I now know how to go about diagnosing problems like those described above without consulting medical professionals. There are, of course, a lot of good resources on the web that can help you sort through any specific problem. I started out this time with a Google search on “knee pain” and found a number of good diagnostic aids including a paper by Calmbach and Hutchins oriented at Family Physicians that helped me sort through what was plausible and what was not, and I am convinced that I have correctly described the injury. Of course, I have to add the usual sort of disclaimer that you shouldn’t “try this at home” and should always seek competent medical advice when needed. I just happen to have a certain tendency to do things myself anyway, and I’ve come to believe that, in many cases, I can do as well or better than any professionals I might try to hire to help me.

David

Third Time’s the Charm? Quicksilver 50K

2009-06-20T14:11:00.000-07:00

Being disgusted and frustrated with missing cutoff times in two consecutive races, I couldn’t possibly take the hint, and instead signed up for another one! (against David’s better judgment). It seemed a shame to let all this hill training go to waste, so I convinced David that I was doing another with or without him, and luckily he decided to come too. This time it was the Quicksilver 50K in Almaden Quicksilver County Park in San Jose. We had some vague thoughts about moving up to the 50 mile after returning to the 50K point, which tacks on an out and back to get the extra miles. Supposedly, you can opt up to the 50 mile but not down from the 50 mile to the 50K. Not wanting to take another chance on missing cutoffs or just having a bad day with the heat, we signed up for the 50K with the possibility of continuing on. Turns out, 50K was quite enough on this sunbaked day, and I was happy enough to stop with that.

The picture (pre-race) below was swiped from Donald Buraglio’s site. (Thanks Donald!) David is #117 (currently ~187lbs, down from 220lbs a year and a half ago). Fifty mile winner Chikara Omine is #75. Jean Pommier and Mark Tanaka with backs to the camera. Many other folks I don’t recognize—apologies). For more pictures and a report on the full 50 mile race, see Donald’s post.

The race started at 6 am, before the sun’s rays began to heat us up. We climbed a few initial hills on a fire road, mostly walking where I was, then ran down the road again and off onto a wooded trail following a meandering stream. This section was shaded as the sun rose, and was full of lovely gentle inclines and downhills. At one point I jumped over the stream crossing rather than climbing carefully down and back out again, and strained something in my foot—I thought it was broken it hurt so much! but it gradually settled down. I need to remember that I’m not 20 anymore! We came out onto fire roads again and more uphills, longer though still gradual and runnable, and still mostly shaded and cool.

Reaching the first full aid station (Dam overlook), the sun had only just peaked over the hills. More fire roads with runnable ups and downs, mostly in the shade, and the second aid station was upon us, more brightly lit and exposed to the sun. These volunteers looked to be getting warm. By this point the runners were pretty spread out. A few people had gone out too fast and were slowing down, and I was able to pass a few folks. We came upon Sean Lang and Gordy directing traffic, and soon there was a long fast downhill section leading back to the dam overlook aid station. I tried to make up for my slowness on the uphills here, and to compensate for having to climb this hill again on the way back. This was now mile 19—my energy levels usually start to fade here, and that’s what happened this day as well.

The next section was not difficult and had a fair amount of downhill, but I was just hot, tired and thirsty, and even the downhills felt bad. It seemed to take forever to finish the 4 mile loop, then climb once more to the Dam overlook aid station. I filled up on fluids and wandered off sipping coke on lots of ice. The long downhill became the long uphill as we retraced our steps, and I managed to muster a run here, but it was intermittent. Finally, there was Sean and Gordy again, making sure we didn’t get lost, then a bit more climb and another long downhill to my last aid station. I was surprised to see I had caught someone, and was inspired to try harder this last section. Only 4 miles to go—how hard could it be? It turned out to be the most difficult part of the course! Soon we were climbing again, short steep hills I had read, but what I found were long steep hills almost impossible to climb at this point. My shin muscles were cramping and I had to walk on tip toe to keep the muscles from cramping worse. I felt a shiver and was sure heat stroke was near too. The hills just kept coming and coming until you forget you thought you’d be finished by now. Finally we came upon the final downhill dash (for those who still had their legs) and the finish.

At this point, there was no question about going out into that heat again. I had made the cutoff time for the 50-mile, but it was miserably hot out there on that trail, and the thought of crawling up those last few hills again in the heat was more than I could take. It turned out David had had enough too, and he brought me ice as soon as I crossed the finish line.

And what a spread at the finish! There was watermelon, strawberries, meats on the grill, salads, desserts. They even had a generator for power and a full sized refrigerator (now that's serious advance planning) with ice cream, and they filled ice cream requests to order (I had ice cream with strawberries). It was fun hanging out and enjoying the food with fellow racers. I got to visit with Barb Elia and Christina Brownson, and a whole bunch of other folks whose names I forgot in post-50K brain fog. I also got to run for a while with Janice O’Grady, one of the founders of the event who returned from Colorado to run it. I talked with Mark Tanaka for the first time (having one of his usual hectic race mornings), as well as Simon Mtuy and Jean Pommier. The 50-mile winner, Chikara Omine was amazingly approachable and gracious, though a superstar already at 26 years old. See Mark Tanaka’s interview. And I finally got to see Bev Anderson-Abbs in person rather than merely watch her shoot by (and even talked with her!). She looks like a consummate athlete—lithe and well muscled. Maybe someday…

I was able to keep my heart rate more consistent than at Diablo or Miwok, which could be a sign of some improvement in pacing. I typically start a race between 150 and 160 bpm, and hold that for a few hours, but the HR gradually drops for unknown reasons over time, down to the 140s, and when I’m really dragging or cold, into the 120–130s. It’s an interesting chicken and egg question—does heart rate decline because of fatigue, or does fatigue increase because of HR decline (the heart can’t deliver sufficient oxygen)? The hints I’ve gotten from questioning coaches is that as glycogen is depleted, there is less energy for anaerobic energy production, and the aerobic heart rate is much lower (see the Maffetone formula, that works out to about 135–140 bpm for someone my age and condition. For other lucky souls, it might be much higher and hence they can blow by me without even breathing hard). I’ve been looking through the research literature, but I still don’t understand the connection between exercise intensity, muscle glycogen reserves and heart rate, but presumably it has something to do with blood lactate levels. This time I also didn’t bother with Vespa, though I had tried it previous races. I think if anything, my energy levels were maintained better than usual, but that may have more to do with pacing and the course.

We decided to experiment more seriously with David’s carb-free race nutrition approach, and have him try and run at his own pace to see if he’d bonk with no carbs. So David started out faster and I didn’t see him the rest of the day until the finish. (and I was lonely…) I carried all kinds of food with me, most of which I never managed to eat. Funny how that always happens. I started out with a bottle of full strength Cytomax, but it got diluted as we went along with the watered down stuff. I forgot one of my water bottles, and so never had the ability to carry extra water—when it grew hot, that became a problem. I ended up eating a few gels, few bites of potato and cups of coke, and a couple ounces of roast beef that I brought along in my pocket. Maybe 500 calories in but ~3000 out (walking uses less than running, but 5500 feet of climbing must count for something).

I was happy to be 54th out of 75 finishers and 5th out of 7 in the 50–59 women (not completely back of the pack for a change) in this field that included 19 first ultra runners (many of whom were faster than me!)

David finished successfully without using any carbs in 32nd place overall (and 7th out of 12 in the 50–59 age-group men). He was running with a heart rate generally in the 150s, substantially above the mid 130s that he typically maintains at my pace, and well above his purely “aerobic” effort. Toward the end he reported distinctly slowing at the same heart rate, but that was probably due to a combination of increasing heat and steeper trails and calf cramps. (The hardest hills, both up and down, in this race are at the very end!) He said he couldn’t sit down to rest for about an hour after the race because his legs kept cramping! It was definitely hot there at the end, and I was glad I managed to keep the cramps at bay as well as I did.

The aftermath: the lung irritation and asthma from before Diablo finally disappeared for good (and hasn’t come back thankfully). My foot (that I thought might be broken) was tender and slightly swollen for a few weeks, though I kept running on it anyway, but mostly has settled down again (though the bones look thicker now—got stronger?). Some hot spots on the balls of the feet, but no blisters (thanks to Drymax socks!)

Miwok 100K Wade-Slide-Walk-Run

2009-05-05T14:15:00.000-07:00

Cynthia had some concerns going into this event regarding recovery from Diablo and illness. Though the lung injury incident didn’t seem to have much effect at Diablo, she was coughing and asthmatic all week after, and actually came down with a fever for the early days of the following week (and thought it was swine flu!). Trying to heal and prepare, we did very little running all week, and just tried to get Cynthia’s lungs settled down again (she kept using the steroid inhaler/bronchodilator and upped the vitamin D intake to 10,000 units for the week). This seemed to work, more or less, and we prepared drop bags containing an extra shirt and our Firetrails 50 jackets in case it was cooling off by the second time around at Pan Toll. Cynthia was trying some new food ideas this time as well (mashed potatoes and carrots and sliced turkey, along with more V8 juice!). We headed out as planned on Saturday morning, after getting what little sleep we could when the alarm is set for 3 am.

The weather forecast going into the race was for a mostly cloudy day in between a couple of bands of showers the previous day and the next. We started out in typical Headlands fog just as the sky was starting to lighten up a bit (5:40 am). We started with a brief run across Rodeo Beach: “See that light over there? Run to it, then follow the pink ribbons.” But then we were immediately bottlenecked waiting to get onto a single-track trail, and it wasn’t until we turned onto a paved road that runners were really able to start spreading out and sorting themselves out by speed—that made the first 10 minutes a pretty slow walk for those of us who started near the back of the crowd. Those first few minutes lost turned out to be critical to our day.

Most of the first 10K up to the first aid station was on pavement or gravel fire road, and the weather looked like it was clearing a bit as the day brightened. We kept the pace down (145 beats/min for Cynthia) in hopes of maintaining energy levels more constant during the day. We walked the steeper hills and jogged easily on the gradual ones, taking walking breaks to keep the energy output low. Finally there was some downhill, and we sped up to take advantage of it. Cynthia was going to try Olga’s advice to Rooster to run hard on the downhills, and for a brief while we cruised along at an 8-minute pace, though when we turned off onto trail, we slowed down to a 9-minute pace, despite an effort to keep the pace up. It’s just a fact—trail running is harder than street running.

However, weather-wise, things gradually worsened. Heading up from Bunker Hill, the cool fog was more oppressive than cooling, and the humidity seemed like it might be a problem. We headed up and over the hill and then down much faster toward Tennessee Valley, with Cynthia getting out ahead of David again on the slippery trail. A brief stop at the aid station there to make up new Cytomax drink (another experiment this time), and we headed off down the road and on toward Muir Beach. Here for a brief while, the views were gorgeous. You could actually see the ocean and the world around you (and take a few pictures)! But the first of the saturated trail conditions was making its presence felt as we detoured around a giant puddle in the path. Still keeping the heart rate in the 145 range, we continued up the hills toward Muir Beach, down the steep steps slippery with rain, and back up onto another ridge, before the steep descent toward the beach and the next aid station.

After Cynthia drank some coke and grabbed a few chips, we continued on the next leg, which was quite easy and pleasant, paralleling Hwy 1. However, the weather was going rapidly downhill as it settled into a steady light rain. Cynthia’s Garmin 405 started beeping wildly and switching screens constantly (water under the bezzel?), and there wasn’t much we could do about it. Slowing to a walk seemed to help it, and it quieted down going up the steep climb to Pan Toll. Unfortunately, this is where Cynthia slowed down to a resigned trudge (HR doesn’t lie—only 135), and we were passed by a few stronger walkers. Coming at last into Pan Toll, we tried to grab our food as expeditiously as possible, but our hands were fumbling and cold. Cynthia pulled on a long sleeved shirt for more insulation, but it was quickly soaked.

We continued on, but now we were socked in by cloud and pelted with driving rain by what felt like gale force winds, which threatened to blow us off the trail. Despite wearing a hat to keep the rain off, the wind blew rain on Cynthia’s glasses, both inside and out, and she had to keep stopping to wipe off the drops when the visibility was too poor to see where she was going. By now the trail was churned up mud from the previous 300 runners, and had become very slippery and hazardous with a stream running through the trail in most places. We gave up any hope of keeping our feet out of the water, and plunged through the mud and streams, staying upright as best we could. At one point, David slid off the trail and narrowly avoided straining his back trying to keep his balance. The front-runners began making their way back, and we stepped off the trail to let them by, at least when we could see them coming! Finally, we were back into the trees and out of the howling wind, and could see again at least. We made our way into Bolinas aid station, where they were valiantly trying to dig drainage ditches to keep the water away, drank some coke and continued on in a hurry, as this last leg had taken far more time than anticipated.

All the low spots in the trail along the ridge (and there were plenty of them) filled up with water, and many runners didn’t even try to skirt the edges of the lakes. Those of us who did try didn’t always succeed; we were all contending with soaking wet feet. Running through the puddles was the path of least resistance, but unfortunately, you can’t tell what is there, and might find yourself in a hole! Lakes alternated with rocky outcroppings, and you could never be sure whether to prepare for slippery mud or gripping rock. We were discouraged by the conditions, but trudged along the rolling hills toward Randall turnaround.
Since so much of the trail seemed different from the published altitude profile, we couldn’t tell how far along we really were. The Garmin isn’t that accurate under trees and in rough terrain, so we couldn’t be sure how far we had to go. All we really knew was that this was taking forever, and we had not yet encountered the expected steep downhill. Finally, we reached the turn, and knew that there was still 1000 ft descent to be made in this torrent of a trail. Cynthia took off in desperate hurry, sliding and pounding through the mud, but to no avail, we missed the cutoff time by 4 minutes. Chuck Wilson (aid station captain) pulled us for missing the cutoff (again!) and kindly let us sit in his car while they took down the aid station. Several more runners soon joined our ranks, and we got to talk with Hwa Ja Andrade and Don Wilkison while waiting, both also surprised and out of sorts for being pulled. So our day ended at the turnaround, and we were driven back to the finish to eat, warm up, and collect the extensive race swag.
OK, so much for the conditions! Miwok was a sharp contrast to the heat of the Diablo 50-miler two weeks earlier, but ultramarathoners have to learn to contend with whatever nature throws at them. Apparently, we still have a lot to learn. There was a relatively high no-show rate at the start, and quite a few were forced to drop out when they were unable to stay warm enough and found themselves with insufficient clothing, even some of the top runners. But surprisingly few people actually fell or hurt themselves; these were a tough lot!

But the conditions really slowed everyone down. You can’t run full out when you’re constantly struggling to keep yourself upright and not slide off the trail or zigzagging around puddles. Race management, however, did not see fit to take the conditions into account, and they continued to strictly enforce the predetermined cutoff times. A significant fraction of the runners who made it to the turnaround at 35 miles did so with just a few minutes to spare before the 8 hour and 40 minute cutoff, as judged by the steady stream of people we passed on the way down. Unfortunately, we missed it by 4 minutes (about 0.8%), even though the time allowed for the return trip to Pan Toll was 4 hours (next cutoff time was 6:30)! Even under these conditions, we felt we could have made it the 14 miles back to Pan Toll within the allotted time. Another runner who arrived at the turnaround a few minutes after us was even exactly on his planned race pace—he unfortunately had failed to notice that his planned pace brought him into the turnaround eight minutes after cutoff, even though he had both numbers carefully printed on his laminated race plan. The cutoff times were based on an assumption that you would be slowing down significantly later in the race. In this case, a bunch of us arrive at the turnaround in good condition and quite ready to continue at much the same pace—in fact most of us probably would have made the next cutoff had we been allowed to continue. Not surprisingly, there were significantly more runners who missed the cutoff this year than in previous years.

One of our difficulties with this event stemmed from our relative inexperience on the course. The elevation profile is so abbreviated as to be useless. The initial hill looks like a single climb and descent, but the hill is full of false summits and downhills. So we weren’t sure what the rest of the course held in store based on how the profile failed to fit with the reality. This became a problem later, when we were unsure where the turnaround was, and what to expect on the ridge. There really is no substitute for familiarity with the course, and we should have spent some time up there in advance, trying out the course.
David continued his now-standard practice of fueling himself before, during, and after the race on almost entirely fat and protein. Heat (Diablo) and cold (Miwok) did not affect his nutritional needs. Cynthia was pleased with how easy and satisfying turkey and mashed potatoes were (not much chewing required). Despite the asthma and illness from the previous week, there was little problem due to lungs. Maybe the clean moist air helped.

The heat at Diablo of course dramatically increased the need for water intake. Electrolyte needs are less clear. David used salt capsules regularly at Diablo and not at all at Miwok. At Miwok he had no muscle cramps or other symptoms of electrolyte imbalance. Cynthia got her usual lower leg cramps, but nothing insurmountable. We tend to believe that it is much more effective to treat muscle cramps with plain calcium carbonate antacid tablets, at least when running under normal conditions. Excessive heat and sweating can increase the need for salt, especially if you are a salty sweater or drinking a lot of water. It makes sense physiologically: calcium ions (not sodium ions) mediate muscle contraction, and our experience, with both ourselves and others that we’ve convinced to try it, is that a quick fix of calcium is more effective for managing muscle cramps than downing a bunch of salt capsules. But, of course, that wouldn’t give much of an opportunity to sell a high-priced specialty product…

Besides calcium carbonate (and salt/”electrolytes” in hot weather), our other standard carry-along item is ibuprofen. Cynthia usually starts out with it (or Aleve) to prevent the achiness catching up too early; David can get through easier 50K events without needing any at all, though he does take ibuprofen at the first sign of significant muscle fatigue if there’s a long way to go yet (typically at least 20 miles after the start).

Another innovation we successfully tested out at Miwok was field recharging of Cynthia’s Garmin 405. The standard charging cable connects to its 5 V charger using a USB connector. (You can therefore charge it directly from any computer USB port, if you want to, though that’s not particularly helpful on the run.) But you can also buy “USB batteries.” Ours is made by Lenmar and is a compact 2.5Wh Li-ion battery with a USB connector built in that weighs in at a little over an ounce. When the Garmin internal battery started to run out after around 7.5 hours, we connected the battery and charging cable for a half-hour or so, and were ready to go for several more hours. (Repeat as needed; the USB battery capacity is much greater than the internal Garmin battery.) The only drawbacks are running with the wire wrapped around your arm and securing the battery (in your hand or a pocket), and the functions are not accessible while it’s charging (though it continues to collect data). If you remove the charger for a brief period, you can check your progress, then continue the charging process. In principle, this practice could allow use of the Garmin for 100 mile events or longer (no, we’re not ready for that yet!)

The aftermath and lessons learned: Cynthia’s muscles are (surprisingly) still sore three days later —must be due to the faster downhills. Also, lower abdominals are very sore (iliacus and psoas). David—no pain at all as usual (really, really unfair). Feet survived ok—hot spots seemed much happier running wet and cool. No falls, no injuries. David is still satisfied with his fueling strategy, Cynthia is not—what food she had stayed down well and kept fatigue and nausea away, but was eaten too little or too late to keep her energy levels high. Cytomax was fine, but she got too little of it too apparently (only two bottles).

It seems that trying to keep the pace down at the beginning was the wrong strategy—at least it didn’t seem to prevent Cynthia’s slowdown near the 20-mile mark, and instead just resulted in lost time. Perhaps the biggest mistake was taking it easy on the climb to Pan Toll, where we lost time and got chilled, and once chilled, it was harder to use our hands to put on clothes at the aid station, harder to get at our supplies, harder to move at all. Cynthia is a lousy walker on hills, and needs to learn how to run them or at least walk faster! We expected to perk up and make better time after Pan Toll, but the weather interfered with that bit of strategy. It would have been better to make good time earlier and not hope to make it up later.

So, Miwok remains another piece of unfinished business. Maybe next year will be better, assuming we even get in. Meanwhile, we did get cool race swag as you can see. The women’s shirt has a built-in bra, and the men’s shirt is handsome and manly. The caps are nice and have curved brims (maybe to keep the rain out?! Where were they when we needed them?) We’ll have to try running someplace actually cold to make use of the gloves. The coolest goodies perhaps were the Miwok Trail Ale and glass to drink it in. There was also a nice water bottle that we forgot to include in the picture.

Diablo kicked my butt!

2009-04-28T11:36:00.000-07:00

I was thrilled and excited to try out my hill training on the Diablo 50 mile course, though in retrospect I probably should have just signed up for the marathon, since I told myself it was meant as a good hard training run for Miwok. Considering that the times for Diablo 50 are about the same as Miwok’s 100K, that pretty much says it all—Diablo is not a training run for anything- it’s a serious encounter in its own right.

Starting out on single track

A bad omen occurred on Saturday: I happened to be buying some supplies and saw alpha-lipoic acid supplements that I had just read about on Mark’s Daily Apple, and decided to try them. This material is supposed to be a potent antioxidant, restore glutathione levels and to protect mitochondria from oxidative damage. I read a few other studies about it, and it seemed worthwhile, so I popped a capsule, bent over to see something on the computer screen, and immediately realized I had swallowed it into my trachea! It wouldn’t come out, It was blocking airflow, and as the capsule started to swell from hydrating in my body, I panicked. After a few Heimlich maneuver’s from David and some other unpleasant aftereffects, the pill was out of my trachea, but I went into a nasty asthma attack from the junk that had leaked into my lungs! I am familiar with asthma, having had problems with it in the past. So I had a steroid/bronchodilator inhaler handy, used it and managed to be mostly clear by Sunday AM in time for the race (after wheezing and coughing up phlegm for most of Saturday and Saturday night). Pretty scary experience. Note to self: take pills with water and swallow carefully!

Marching up the hill

But the asthma seemed to abate by race time, and I toed the line with everyone (ok brought up the back of the pack). It was warm already (another bad omen), but was a gorgeous day, and I resolved to deal with the heat as best I could. The ascent up Diablo was as expected. We tried it out a few weeks ago, and it went faster and easier on race day than I expected—something about all the adrenaline. There was very little actual running at this stage, but it was a fun and beautiful and relentless climb. At the Juniper Aid Station I got to meet the very adorable Victoria. I think Miki may have been there too, but I missed her somehow. Meanwhile, we continued to the summit uneventfully, paid our respects to the view at the top, said hello to Don and Gillian running the marathon, and continued on. The downhill stretch was nice—pretty steep, not real fast, but we were cruising. Then suddenly, a hamstring muscle (sartorius?) seized up on me. I’ve had cramps in races before, but they are usually annoying little things, like in the foot or lower leg, something you can run through. But suddenly I found myself immobile, unable to even walk. David came to find out what was keeping me and massaged it a bit, and when it finally stopped seizing, I walked for a while taking copious amounts of water, Enduralytes and calcium carbonate, and gingerly started jogging again. (The cramps never did return, but that muscle hurt for days after.) We hit Juniper again, the day becoming quite warm, refilled on fluids and food and continued on the long rolling downhill stretch to North Gate aid station, admiring the views while trying not to go flying off the trail. Somewhere along this trail, there is a patch of sparkly minerals (mica maybe) that made it seem like we were entering Disneyland or some fairy tale. I longed to just sit and play with the stones, but it was baking hot in the sun, and didn’t seem like a really good idea at the time with cutoff times and all, so we continued on down and down to the aid station. They were running low on ice, but we took what ice and fluids we could and continued on as expeditiously as possible. We passed a few people during this five-mile loop, people injured or suffering from the heat. This section was quite nice, with some shade and creek crossings, a few encounters with sedate cows and polite horseback riders, and then a long climb back to North Gate, where I was desperate for more water. When we arrived the second time, there was ice and Coke but not much to eat—I grabbed a cookie, though this was not appealing, and tried to choke it down without success. Apparently, it was 93° F in the shade of the tent.

Can you say “steep”?

Then ensued what felt like a death march through shimmering waves of heat on exposed sections of fire roads, up and up toward the Rock City aid station. Though it wasn’t really very far, it seemed to take forever, as the heat was taking its toll on me. I kept my bandana and shirt soaked with squirts of water from one bottle, and this cooling was enough to keep me going, but not very fast. I passed one poor soul suffering from a stress fracture in his foot, keeping his pace to a hobbling walk. The fire road gave way to a shady trail and short precipitous decline, then another half mile or so of climbing on roads until we finally reached the next aid station, just in time for the cutoff. We grabbed some supplies stashed there: a spare bottle of David’s favorite liquid fuel—coconut milk and whey protein, and for me frozen V8 juice and a couple of beef tamales (don’t laugh, I got down one of the tamales eventually and immediately felt better!). In the rush to move on, I forgot the charger we bought to keep the Garmin 405 alive, so it eventually shut itself off, after about 26 miles. I saw Rick returning already just as I was leaving the Rock City aid station. (He looked amazingly fresh and strong for having run 37 miles in this heat already!)

Heading toward Eagle Peak

The trail to Finley Road aid station was quite nice at first, shady and following a stream, but it quickly morphed into more uphills or at least rolling hills on fire roads. This section should have been easy, but it was hot and I was bonking. Eating and running is hard. By this stage I had had three gels and a carb/protein supplement (Cliff Shot Recovery Drink), one square of PB&J sandwich, a small handful of chips and a few cups of coke. Apparently, not enough. My heart rate had averaged 155 bpm for the initial ascent, meaning that I was working at nearly 90% of my maximum heart rate, well into anaerobic threshold, and 140 bpm for most of the rest. Since I rarely train at that high an effort for long periods of time, I’m pretty sure I was glycogen depleted, despite trying to supplement. Of course, David was having an easier time of it, waiting patiently for me, and feeling good. Managing the best speed I could, we continued on our way, passing many others on the return, all saying “Good job.” I finally understand why ultrarunners say that—it’s because it’s short, sweet, and positive, and best of all, keeps you from looking like a moron when you can no longer put words together to make a sentence because your brain has ceased functioning.

Almost there

The day was waning by now, but not the heat. We started the last long steep hill leading down to the Finley aid station, and I was completely dreading having to trudge back up that hill. I was pretty sure we wouldn’t make the next cutoff at Rock City due to my utter slowness, and was ready to drop here. I saw my friend Chuck Wilson, a veteran of 200 ultras, sitting there with legs that refused to work anymore, and he was getting a ride back. This seemed like a great idea at the time, but the aid station volunteers explained that we’d have to get back on our own because they didn’t have room in their vehicle. Another guy came up hoping to drop as well as his knee was in bad shape, but we were all sent back up the hill. Then another guy came down the hill, suffering mightily from leg cramps, but we told him no one else was getting out at Finley—he would have to head back up the hill too. We left the two suffering men to keep each other company and struggled to get back to the Rock City aid station. I hope they got back OK! I talked to one man’s worried wife, but she couldn’t reach him on her cell phone at the aid station.

View from the top

I resolved to get up this hill and back to the aid station as best I could in a vain hope of making it by the cutoff time. I suggested to David that he go on ahead and try to make it, but he opted to stick with me. (Thanks!) I chomped down finally on my tamale and just kept going up the hill—and you know, once I had some fuel in my belly, it wasn’t so bad! We had also brought some applets and cotlets, which I had forgotten to eat earlier due to my brain fog. Once the tamale and sugar were in my stomach, and the shadows were getting longer and the breeze cooler, I felt like a new woman and was ready to continue. But alas for naught, they pulled us from the course, and I joined the other runners in the van for the long drive back to the finish, many of whom were in much worse shape than us—nauseous, crampy, and exhausted. Diablo certainly took its toll that day.

The way ahead

I’m pretty sure I could have finished the race in time, but wasn’t given the opportunity. There were supposed to be 150 starters for the 50 mile, but only 106 finished. On this particular day, that was doing pretty well I’d say. I don’t feel too bad having missed the opportunity to finish. It just means I’ll never rest until this particular devil is met and conquered—maybe next year. That said, it’s probably for the best. It turns out I was developing a blister on the ball of one foot unawares, and if we had continued, it could have become very painful and I might not have been able to recover very well. As it was, I had three blisters in spots I wasn’t expecting on my right foot, but the left foot was perfectly fine. Completing 37 miles at Diablo is certainly enough for a training run for Miwok, but I am humbled and lacking in confidence at this stage, and worrying about making cutoffs once again.

The aftermath and lessons learned:

The lung injury due to inhaling lipoic acid wasn’t a problem during the race, but the asthma and congestion plagued me all week afterwards.

Minor blisters, quads were sore on Monday- we went for a walk which was fine, but legs said resounding “No!” to running even a few steps. Tuesday, legs felt better, gave them a nice walk anyway. Wednesday was another rest day, mainly because of time constraints. Thursday, antsy to get back on the trail, we ran some short hilly trails with no soreness. Friday an easy recovery run, trying to keep heart rate down, and did a familiar loop in better time than expected. Saturday, we ran 13 hilly miles, but I got completely exhausted by the end—maybe I’m not so recovered after all! I conclude we did a fine job of acclimatizing the quads and gluts to the rigors of hills, but I still need to work on basic endurance and speed.

Keeping the bandana and T-shirt damp is very helpful—but carrying ice in your hands is even better (my hands are always hot when running). The frozen V8 juice was delightful—I used it to chill my hands and arms and neck, and wished I’d brought another bottle full. I wish I could have managed Rick’s suggestion to put ice in a bandana around my neck, or put it in my cap, but in the rush at aid stations I could never remember to. Even so, in real heat, ice doesn’t last long. Carrying enough water is essential. I was constantly and voraciously thirsty, and this is very unusual for me. Once I remembered to start taking salt and calcium, cramps were kept at bay.

V8 juice is delicious on the trail (so is chicken broth, turkey sandwiches, sushi, pretty much any “real” food IMO) . Aplets and Cotlets are nice—not so chewy and sticky as Cliff blocks- and go down well. But basically, I’m still looking for a fueling strategy that works for me. It could be that I need to hold back so as not to glycogen deplete quite so fast, but that’s not a great option, being slow and all. It could be that I need to supplement even more with gels etc., every half hour or something, or that this is not necessary at all and not a good idea when using Vespa (which I did). David is still sold on his fuel, easy to drink, no muss or fuss. Maybe I should try it!

Finally, one of the rules of training is specialization: in this case, it means if running Diablo, train at Diablo, because nowhere else are the conditions quite so tough!

Here are some more pictures. If you want to be identified in any of these photos, leave a comment!

Eagle Peak from beyond

Trudging up

Baldy Ridge

Deer Flat Road

On the way up to Juniper Campground

Getting close

Breaking into a shuffle

Across North Peak to Sacramento River

Back toward Eagle Peak

Of course you can just drive to the top, but where’s the fun in that?

All the way up the steps to the tower

Down, down, down toward North Gate

Getting hot on those exposed trails

Horses looked hot too

Trudging desperately toward Rock City and a reprieve from the heat

Getting closer to Rock City

Single track toward Finley Road

We’re Officially Insane!

2009-04-15T13:19:00.000-07:00

OK, we’re officially insane now having signed up for the Diablo 50 miler only two weeks before Miwok 100K.

Don advised me not to, and I bet he’ll be saying “I told you so” in a few weeks when my dead legs refuse to move during Miwok. But what the heck, next year this time I’ll be even older. A lot can happen in a year. And I’m a sucker for punishment (poor David isn’t, but he kindly agreed to come to make sure I stay in one piece!)

That said, we’ve been hitting it fairly hard on the hills of late and I was very pleased to not be sore for more than a day after Pirate’s Cove 50K. We also did some long runs, for example, heading up the Bay to Ridge Trail (the part from Arastradero Preserve to Black Mountain and back through Rancho San Antonio) (see Jean Pommier’s write-up of a similar run), Windy Hill and along the ridge to Borel Hill (see Russian Ridge and Skyline Ridge web pages) and back down via Alpine Road, and the PGE trail in Rancho San Antonio up to Black Mountain and back another time, with only minimal quad soreness. All of these routes entail miles of downhill running. Practice in downhill running is crucial to developing quads that can resist the stress of eccentric contractions, and it has been reported that even a single session of downhill running can protect against quad damage. Here are a few papers discussing these effects:
Decreased blood oxidative stress after repeated muscle-damaging exercise
Characterization of inflammatory responses to eccentric exercise in humans
Recent advances in the understanding of the repeated bout effect: the protective effect against muscle damage from a single bout of eccentric exercise

Diablo is another matter though, as I discovered when we checked out the first and last legs of the course a week ago, up to the top of Mt. Diablo via a couple of far-from-insignificant side peaks (such as the aptly named Eagle Peak which actually had a bald eagle soaring overhead!) and back to the finish—just hellacious climbs and descents, but oh so beautiful. Two days later, my quads still hurt. Not a good sign. I’m wondering whether our relatively tame hill training is going to be enough. The relatively short sections on fire roads were the fastest parts, but the tiny twisted gravely rooty steep single track (is that enough adjectives?) is slow as molasses. I don’t know how the fast people can manage it—all the power in the world can’t make those treacherous trails fast! But somehow they do it. I just want to survive and not be out too many hours after dark! The goal race after all is Miwok, so I reassured David that I wasn’t afraid to drop if I thought I was getting too beat up to recover in time for Miwok (sure, sure I will…). Also, those trails were particularly hard on the balls of the feet, since so much of the time I balanced on larger rocks rather than scrambling on loose scree (is that a word?) for secure footing. Anyone have a suggestions for problems with too much friction on the balls of the feet? I’m wondering if blister prevention patches in that location would help or hurt?

The injuries I was complaining of back in January haven’t completely gone away though they no longer ache and keep me awake at night, most of the time at least. Some nights I’d sleep with a tennis ball pressing on the sore spots (it seemed to help!). My gluteus medius, IT band and rectus femoris still ache, but my “posterior chain” (gluteus maximus, hamstrings, and calves) have gotten their act together and are no longer a severe limiter (ok, they still ache, but work properly now). Many thanks to David for endless massages and cross-fiber rubbing! The exercises that seemed to help include lunges (adding in the hip flexor stretch), supine bridges, step ups (see Eric Crissey’s Butt and Hip Care articles, part 1, part 2, and part 3 ["Healing the Hips"]), myrtls (thanks Glorybelle!), piriformis stretches (thanks Lori!) and just lots of slower running (faster running risks flare-ups again). I like Cressey’s stuff even though he’s really oriented toward the weight lifting crowd. Here are a couple more interesting articles he wrote:
Five Resistance Training Myths in the Running World
Cardio Confusion

In fact, I think I was suffering from something called femoral anterior glide, where the hip flexors literally pull the head of the hip bone forward in the socket, causing pain and dysfunction. My gluts weren’t activating properly. Now they are better and that problem disappeared (knock on wood!). In fact, I could feel everything engage properly on the climb up the steps above Rodeo Beach back in March when we ran PCTR's Pirate's Cove 50K, and felt good for a change. It’s amazing just how screwed up things can get when one muscle doesn’t engage properly.

I feel like I have trained as well as I could given the injury from last January and limited ability to tolerate higher training volumes (a few 50+ mile weeks, but with lots of hills). Now we’re tapering (long run only 12 miles and 2000 feet climb!) and easing up for a bit on the everyday runs (can you say lazy?), and hopefully that will help get us through. So stay tuned to see if we survive Diablo! It’s going to be a long day!

Fremont Fat Ass 50K run report (or running while injured)

2009-01-27T13:49:00.000-08:00

I have been suffering from an injury of late that is threatening to derail any short term race plans I have. The injury is hard to pinpoint but is loosely in the gluts/ piriformis/ ilio-psoas areas. See GetBodySmart for a great site the shows anatomy and physiology in a way that you can clearly see what each muscle does and where it attaches.

It’s not clear exactly what the problem is, or why it showed up suddenly. I can’t tell if the problem is from a change in training to more street/track/tempo running (less steep hills, more consistent running) or the difficult trails we did two weeks ago. It would be ridiculous to be out of shape for trail running because of doing predominantly street running for a few weeks, but that is the possible root of the problem. David of course is immune from injury—at least it seems so most of the time. I blame it on the testosterone (keeps his muscles strong even when he doesn’t exercise! Men have it sooo easy!)

After recurrences of pain in the last couple weeks, mostly on the downhills when I would attempt to stretch out my stride and enjoy the ride, I decided I needed to nip this in the bud and not wait another few weeks to see if it would get better on its own like I did last summer. I went to see a physical therapist last Thursday, who gave me a whole bunch of exercises to do (toe and heel walking and core strengthening exercises).

Of course I hadn’t had much time to do the exercises or change anything by the run on Saturday, so it was with some concern that we showed up for the run on Saturday AM. I wasn’t sure I’d get all that far before having to call it quits. I was well anesthetized with Aleve, but was forced to further supplement with ibuprofen eventually in order to finish. Not so good really.

As for the run, I took it very easy and ran much of the first half with Mountain Man Steve who is successfully recovering from a calf injury and preparing for Coyote Two Moons, and Jim Winne who was deliberately keeping his heart rate down to accommodate his heart problems. As expected, after about 5 miles, the pain began, despite keeping the pace down. The course was quite easy, with clear dirt or paved trails, 90% flat or very gradual hills, perfect weather. Every time I tried to get the pace up though, I had to back off or was forced to walk. Ten minute miles (preferably 10:30 to 11) were about as fast as I could go without more serious warnings, and pushing it into 9:30 pace did some damage. Average heart rate for the run was only 137! That’s pretty slow and easy.

The weather was cooperative (cool and overcast with only a little drizzle). There was even an aid station! I met more great runners: the famous ultrarunners Chihping Fu
(thanks for the aid station!), Barbara Elia and Linda McFadden. There were lots of other great folks out there but I couldn’t spend much time talking with everyone due to pace differences and didn’t get everyone’s names. (Apologies to those I am neglecting to mention!) It was also nice to talk with the faster folks at the finish (Mike Palmer and Catra , the co-RDs, thanks for the pizza and beer, Ron!). Catra was recovering nicely from her IT band problems from HURT and seemed ready for more! Everyone was having fun and taking it easy, just a fun run on a Saturday (see participants and finishing times)!

I stayed reasonably well fueled I think despite skimping on breakfast (coffee and a Trio bar), and ate half a turkey sandwich, a Mountain Dew, and a whey protein energy bar. That’s not a lot of food, but I ate every time I felt I needed to. David again did the distance on near-zero carbs: coconut milk and whey protein (and not that much of either) as his major calorie sources.

Since I was forced to keep to a very slow pace by the pain in my butt and thigh, it was an interesting test of purely aerobic exercise vs. my usual sort of 50K race performance (as much lactic acid as I can stand). The funny thing is that on the day after this easy run, I saw the usual 2 lb weight gain again. I thought that maybe the post-race weight gain was due to the stress of hard running and wouldn’t happen after an easy run. Now I’m wondering if it’s just due to overindulging afterwards in carbs (new glycogen stores add water weight) from the post-run and dinner refueling: pizza, beer, sushi, sweet potato, cherries and bread. That’s a lot more carbs than I usually eat in a day, so maybe I carb-loaded after the run (now that’s just silly).

The aftermath of the 50K wasn’t too bad in terms of muscle pain and stiffness on Sunday. I felt a lot worse after going to the track last night and trying to get the pace up again for a short tempo run. Something’s definitely not right, and I will probably have to back off from anything faster for a while (including races) and concentrate on core exercises and going slow, if at all. So frustrating!

We Were Selected in the Miwok Lottery! YIKES!

2009-01-16T07:28:00.000-08:00

We found out on Saturday that we made it into Miwok 100K, and I am excited and a bit terrified. Our first 50 miler was Firetrails 50 last October, after a series of pitiful 50K trail run times (at least for me), and was a purely spontaneous desire for adventure and experience. We made it well enough within the cutoff times, though not at all speedily, and I ended up thinking that I could have gone further if necessary (though I was almost too tired to eat at the end! For me, that’s pretty tired!) So, in principle, this 100K shouldn’t be such a scary ordeal. I think part of the scariness is the fact that I’ve seen these hills up there in the Headlands, and they are not to be trifled with. The other aspect is that this isn’t just spontaneous, we’ve signed up 5 months in advance. That’s 5 months to plan, worry and fret! (oh yeah, and prepare!)

It also brings up the question of what other races to include in the 2009 schedule, and how to train for these events. I’d really like to do a regular street marathon (in a time that doesn’t embarrass me too much) and am considering Napa Valley Marathon on March 1st. But is training for a street marathon compatible with training for Miwok? Inquiring minds want to know (at least this inquiring mind does!) Training for a street marathon, as I understand it, involves training to increase running efficiency and maximize fat burning while flirting with your lactate threshold (a little too fast and you pay a painful price, a little too slow and you, well, take a little longer). Training for Miwok though—that’s trails and hills and trails and hills, ad finitum, well up to about 16 hours worth if you’re near the back of the pack as I suspect I will be, figuring out what gear to use and training your feet and everything else for the challenge. They seem like incompatible objectives. Please feel free to jump in here with advice, though probably at this point it’s too late to make much of a difference anyway…

Another race I’d like to include is the Diablo 50 miler, about two weeks before Miwok. Maybe that’s cutting it too close, I don’t know. I think it depends on how aggressive we are about that race—after Firetrails, I had swollen ankles and legs and was up 3 lbs of fluid for most of a week. But it’s possible we are adapting somewhat because the ankle swelling/weight gain seems to have diminished (no excessive weight gain or ankle swelling after last weekend’s 20 miles through El Corte de Madera and Purisima Creek Redwoods Open Space Preserves—and I wore myself out on those hills and have been sore all week).

In addition to training, running and more running, and oh yeah hills, we are motivated to get back onto a weight loss trend, instead of just holding steady like we have since August. I really don’t want to have to lug an extra ten or twenty pounds for the whole 100K distance. And who knows, we might even get faster too! So this is a good motivator to be more disciplined about our diet. The good news is that there was no appreciable weight gain over the holidays because we were able to mostly stick to low carb eating, even for desserts (yummy truffles and pecan pie heavy on the pecans and light on the sugary filling). I am not disciplined about food, and have enjoyed the low carb/paleo diet because I do not have to be disciplined (unless someone is waving carbs in front of my face). I cannot stand being hungry and feeling deprived. Still, something’s gotta give. David is really getting frustrated—he was down to 185 lbs briefly in the summer, but went back up over 190 after we started ultrarunning (now on a downtrend again). And running more only seemed to make the weight go up a little more. Since our last 50K on December 13th we’ve been taking it easier, taking more rest days and putting in easier distances mostly, shallower hills, moderate heart rate training. But that hasn’t done anything to help get the weight loss going again either. So now we’re going to try to be more cognizant at least of total calories and cheats and see if the weight won’t come off again. Wish us luck!

USDA Food Pyramid Update

2009-01-13T19:18:00.000-08:00

The USDA will be updating its food pyramid again next year. At present there is little or no representation from the low-carb community on the panel charged with creating the update. Dr. Michael Eades is soliciting comments to be passed on to the panel on his Protein Power blog. If you are interested in contributing, go to his website and provide a comment. I have reproduced below a comment that I posted there.

Let’s see… populations that have found low-carb diets to have significant health and performance benefits: overweight and obese, diabetic, epileptic, persons at high risk for heart disease, models, actors, endurance athletes (have I missed any?); populations that have problems with low-carb diets: none (unless maybe you count those whose problems are in the form of poor acceptance by family, friends, and coworkers…) But it’s “unproven,” isn’t it? Well, we’d all like to see more extensive data on larger populations. But surely, the obvious failure of current dietary recommendations which HAVE been tested extensively and shown to be seriously flawed, suggests that we need a new approach. Low-carb diets which have shown such clear benefits for so many populations are so clearly superior to the current food pyramid, that we are due for some class-action lawsuits (against the USDA, individual panelists, other medical societies, food industry lobbyists, pharmaceutical companies?) for so blatantly putting self-interests above public health!

My personal story: mid-50s, low-carb for one year after a lifetime of high-carb diets. Used to tolerate high-carb diet well and be able to eat large meals without gaining weight. Weight crept up over time, then started rising faster. Gradual appearance of symptoms of metabolic syndrome (fasting glucose up, blood pressure up, weight up, etc.) Low-carb diet rapidly reversed problems: lost 30 pounds without calorie restriction, blood pressure and fasting glucose down, improved general health and athletic performance (I took up running ultramarathons and now do so on little or no carbohydrates and feel good during and after the events [and I now comfortably run hilly distances of up to about 20 miles/4 hours on no supplemental food at all]). And no, the high level of exercise did not result in my weight loss and health improvement; rather the health improvement and weight loss ENABLED me to increase my level of exercise. If anything, the weight loss has plateaued and reversed slightly with increasing exercise.

It is clear that there are populations that can tolerate and even thrive on high-carbohydrate diets for a lifetime. But my best estimates from data I’ve seen is that these are a minority—probably well under 20% of the general population, and they probably represent predominantly people with either limited access to food and/or people with a high level of daily physical activity.

My recommended changes to general dietary guidelines: start with a baseline of about 20% carbs, 65% fat, 15% protein. Increase carbs only if weight GAIN is needed. Decrease carbs further for weight loss or other specific health conditions such as diabetes. Increase protein if needed for muscle building/repair (athletes). For most people, this sort of diet is best achieved with a lot of meat, fish, nuts, and vegetables, though details can vary widely depending on availability and any religious, cultural, or specific health/allergy issues. Sugars and simple starches should be used sparingly if at all. These include nutritive sweeteners, most wheat, rice, corn, and other grain products. Fruits should also be limited: most are nutritionally predominantly sugar water. Dairy is more controversial. Personally, I do not limit dairy consumption, although some people find it desirable to limit or cut dairy entirely. Legumes and legume products (such as soy products) should probably be consumed in moderation, and may be left out by personal preference. Within these general guidelines, try to eat a wide variety of food.

I think it is most important to focus first and foremost on getting these macronutrient guidelines established and understood. Micronutrients are clearly also important, and since fat is to be recommended as the major source of calories, it is probably also important to recommend emphasizing or avoiding particular types of fat, but these kinds of recommendations should be given a secondary status to the macronutrient recommendations. The “wide variety of food” recommendation should take care of most micronutrient needs for most people.

Training do’s and don’ts

2009-01-09T13:28:00.000-08:00

Just for fun, not that we are any kind of expert runners (ha!), we decided to put in our two cents in the TIaRT forum on training do’s and don’ts (I know it’s Friday already!). Some of these thoughts are pretty empirical and based on practical experience over the years, but similar advice is given on the endurancecorner.com training website.

DO:

Do eat high quality nutrition—limit simple carbs, especially if you are trying to keep the weight off (in contrast to the previous conventional wisdom, you don’t need to replace all 400 to 500 g of glycogen stores everyday in an ordinary training day! We keep our intake to probably <100g, but the absolute amount is up to you and perhaps governed by the intensity of your training). Get plenty of vitamins and omega -3 fats and sufficient protein using fresh veggies and meats/fish/cheese/nuts, including vitamin supplements if necessary.
Do get sufficient rest–get enough Z’s, take a day off once in a while or just take a walk instead of feeling like you have to run everyday
Do alternate hard days with easier days and hard weeks with easier weeks
Do experiment with hill work, tempo training, track intervals, etc. to see how you’re doing under different conditions, and race once in a while just for the feedback and fun
Do try crosstraining and/or weight lifting to work on specific muscle and core muscle strengthening
Do make sure you throw in plenty of Goldilocks days (not too hard, not too easy, just the right amount of effort)
Do evaluate yourself critically and welcome feedback from others, then work on your deficiencies (don’t just gloat about your strengths)
Do pay attention to what your muscles and joints are telling you. Sore or tired muscles may need to be warmed up more slowly or rested. Extensive stretching before exercise may be losing favor as a routine practice, but if you have a muscle that is tight or tending to cramp, or other problem areas, do stretch it carefully before and after your run.
Do start slowly. We often find that we don’t “reach our stride” until about 45 minutes or more into a run. Even under race conditions, be careful not to push too hard too early. Do be patient and consistent
Do use a plan if you’re into it, but I’ve had success (some years ago anyway) just winging it and doing what it seemed needed doing (long runs some days, easy on others, track work to speed up a bit, crosstraining on the bike)

DON’T:

Don’t overtrain (back off to really easy once in a while–you’ll know when you need it when your legs are just beat or you start to resent your workouts)
Don’t push through pain all the time—sometimes it goes away if you’re patient, but sometimes it means you need to lay off the hard/long stuff for a while, maybe do some cross training for a week or two or more
Don’t get discouraged—as the Tao Te Ching says “sometimes things are easy and sometimes things are hard…”. You can be sure that what is hard today will someday be easier, and then again, what is easy today will be hard someday when you’re injured or sick.
Don’t worry about what other people think— sure you may look like a dork sometimes, we all do, but you can’t try to look great all the time if it means you’re running a pace far too fast to sustain just to impress others. It can mean the difference between a merely respectable time (ok maybe even a poor time) and not even finishing a race.
Don’t be afraid of a challenge. If you’re not really ready for the challenge, so what? You’ll know what your baseline novice level is and be able to do better next time. Every race, every challenge, will teach you something different about preparation, psychology and equipment that will come in handy later.

One final thought—from reading other contributions on this topic, it’s clear that there is a wide variety of approaches, from those wanting every training detail spelled out to those (like us) just feeling our way along. We haven’t even figured out what races we’re doing this year yet, so it’s hard to begin a training plan! Right now I’m toying with the idea of a road marathon (Napa Valley? Probably haven’t a prayer of a respectable time [i.e., close to finishing times from my distant past], but we may decide to run it anyway just for a baseline number), and we’re waiting to hear about the lottery for Miwok 100K (what the F--- was I thinking?), and of course there’s Diablo 50-miler and some other killer ultra trail events coming up… We’ll see what happens. In the meantime, we’re putting in some easier mileage and watching to see if the heart rate drops with mostly aerobic training as it supposed to do when you’re improving (it does seem to be happening, if slowly). We’re also putting in some tempo runs and track workouts to train for a faster pace that is sub lactate threshold (LT2, as best I can tell where that is—seems to be about 8:30 pace right now for me and maybe 7:30 pace for David) but this is a pace that neither of us can sustain indefinitely. Running on a track is very different from running on trails, especially hilly ones, so we will probably end up incorporating a lot more hills eventually (sure would have helped at Muir Beach!).

Consumer Reports “Secrets of Thin People”

2009-01-04T06:58:00.000-08:00

The February 2009 issue of Consumer Reports features an article called “Dieting on a budget, plus the secrets of thin people, based on our survey of 21,000 readers.” The feature includes some equipment reviews, plus articles on “healthful eating on a budget” and their analysis of their reader survey results.

I often find that I disagree with articles and reviews in Consumer Reports, more so whenever I actually have strong personal knowledge of a product or subject area. Their articles are not, of course, peer-reviewed scientific reports. Nevertheless, and despite the fact that they carefully avoid accepting commercial advertising and sponsorship, they typically conform to current industry norms, assuming, I guess, that their readers are responding to the advertising and product offerings they are exposed to and are merely wanting to choose which of the available highly-promoted products to buy. The same can be said of their financial and medical advice in that their advisors (and authors??) seem to be drawn from the mainstream establishment.

There was a time, a few decades ago, when product reviews often used a home-made recipe or similar non-commercial product as a reference for comparison. Quite often, the commercial products did not compete favorably with the non-commercial version. Such comparisons are very rare nowadays. I suppose it, at least partly, reflects the fact that fewer and fewer people are inclined to make their own anything, even when the results are superior. (Though I will admit that there are at least some real examples where modern manufacturing methods make commercial products that are superior…)

Anyway, I digress. In typical fashion, the results of the survey are presented in a way that contains almost no real data and certainly no statistical analysis. Here's what I think are the real “data”:

Survey date: 2007; 21,632 respondents; 66% “overweight” including 22% “obese”

16% “never overweight”
15% “successful losers” (defined as weighing at least 10% less than at their heaviest and keeping the weight off for at least 3 years)
42% “failed dieters”
27% other

“more than half” of successful losers did so without the aid of a commercial diet program (defined as a particular medical treatment, book, or pills)

The data get pretty thin after that! The report claims that “through statistical analyses [not presented], we were able to identify six key behaviors that correlated most strongly with having a healthy body mass index.” The standard threshold of 25 is used for defining “overweight,” even though such arbitrary BMI thresholds are well-known to be misleading due to variability in skeletal frame size and muscle development.

The basic conclusion of the study was that successful losers generally embraced the allegedly good behaviors naturally practiced by the always-thin, typically slightly more so, and “significantly” more so than did the failed dieters. Therefore, the authors conclude, all you need to do to be a successful loser is to “quite literally, live like a thin person.”

The six behaviors (“secrets of the slim”) recommended turn out to be current mainstream party-line recommendations:

	Succ. losers	Always thin	failed dieters
watch portions	62%	57%	42%
limit fat	53	47	35
eat fruits and vegetables	49	49	38
eat whole grains	“consistently opted for”		?
eat at home	weight correlated with number of meals out
“exercise, exercise, exercise”*	32	31	23

*while the authors suggested that vigorous exercise that increased breathing and heart rate for 30 minutes or longer was strongly linked to lower BMI, the survey numbers are for strength training at least once per week

The authors note that going low carb is conspicuously absent from the list and that limiting carbohydrates correlated with higher BMI in the survey, though they did note that such a correlation could be an artifact of the fact that those with higher starting BMI are more likely to try a low carb diet. Despite this admission, they still claim that “the findings do suggest that cutting carbs alone, without other healthful behaviors such as exercise and portion control, might not lead to great results.”

They also reported that three other strategies did not show significant effects: eating small meals, never eating between meals. and including lean protein with most meals.

Surveys like this are notoriously unreliable for establishing any true cause-and-effect relationships. It is easy to bias the questions to support the conclusion you want to reach. The conclusion about the ineffectiveness of low carb diets is a good example. If only a small percentage of the survey population had even tried it, then, of course, such a diet would show low significance overall, and therefore no conclusion whatsoever can really be drawn as to the effectiveness of a low carb diet.

Another aspect of the report is the definition of “successful” dieters as those who’ve achieved a 10% weight loss (and kept it off for at least 3 years). For the 22% of respondents characterized as “obese,” 10% is barely a good starting point. At the end of the article, the authors, in a section labeled “Realistic goals are one key to weight loss,” state, “A 10 percent loss might not sound like much, but it can significantly improve overall health and reduce risk of disease.” True perhaps, but pretty discouraging from a public health point of view, if that’s the best we can hope for! And we clearly now know better. There are countless examples of people who have successfully lost much more weight and kept it off (for example, by carbohydrate restriction for those who have demonstrated sensitivity to carbohydrate consumption), and they’ve done it without resorting to extreme methods such as bariatric surgery or starvation diets.

At best, one can use survey data like this to construct hypotheses that might be worth testing. To base public health recommendations on the results is ridiculous!

I look at the data and draw a rather different set of conclusions:

We have a serious weight problem if 5 out of 6 people cannot be identified as always thin!
Current recommendations don’t work!
Even those mainstream recommendations that maybe seem to help don’t help very much.

And I would tend to characterize most of the six “secrets of the slim” as not secrets at all, but just things that are sometimes associated with the habits of people who successfully control weight, and not things that can fix it. Clearly, you can do all six “right” and not lose weight. Yes, overeating (oversized portions, eating out a lot) can make you fat, but it’s much more important what you eat and how you manage what you eat: control of portion size is realistically about controlling hunger and satiety and not about counting calories.

The reported survey benefits of lower fat, higher fruits, vegetables, and whole grains probably just correlate with respondents who are generally attempting to pursue healthful habits, a population who are more likely to exercise self control at earlier signs of a weight problem anyway. Also, the statistics presented do not make a very convincing case that these particular food choices are significantly beneficial; only about half of each survey group practiced any particular allegedly beneficial choice anyway. Hard evidence of benefits of such dietary recommendations are actually thin to non-existent. Exercise is good for overall health, but it's a poor strategy for weight control. Being completely sedentary is correlated with obesity, but it is not a cause. If anything, it’s the other way around: obesity causes people to lead a sedentary lifestyle.

And indeed, one could make a similar argument about causation with respect to the whole survey: always-thin people tend to eat less and exercise more because their body condition makes them so inclined. They are sated with less food and find exercise easier and more enjoyable. Trying to emulate the effect (eating less and exercising more) to achieve the cause (weighing less) doesn't work very well! The authors’ conclusion that all you need to do to be a successful loser is to “quite literally, live like a thin person” gets cause and effect backwards.

We’re improving! Yea!

2008-12-11T23:38:00.000-08:00

Well, it seems as if something is improving, albeit slowly. We just completed the Woodside 50K and were pleased to handily beat the cutoff times and bring in a PR (6:31), especially given the difficulty of this course (see profile) relative to our last 50K PR (Skyline-to-the-Sea, previous PR 7:02). The other amazingly cool thing is that I didn’t fall down during this race (though David took a roll instead, thankfully with no injuries). We’ve also benefited from some eye-opening information from using the Garmin 405. Despite its inevitable inaccuracies, it has helped me come to terms with the unpleasant reality of my basic physical condition, what I’m capable of or not, and being realistic about my current status. This allows for focusing on (or trying to focus on, anyway) effective training. Needless to say, I will not be challenging the winners (newcomer Keith Bechtol who smoked the course in 3:36 and destroyed the previous course record of 4:14), but I did come in only ten minutes behind the previous woman in my age group. David was kind enough to pace and encourage me, even though his heart rate monitor revealed that he was consistently performing at a rate about ten beats per minute below mine—in other words, he could have worked a lot harder and gone a lot faster. Thanks Sweetie!

We started out with the pack and just tried to cruise the initial downhill and subsequent climb, which became steeper eventually. David kept telling me I was pushing too hard, and he was right of course—with a heart rate in the mid 160s, I couldn’t sustain that pace the whole way, but I was going to do my best to meet the first cutoff at Bear Gulch (18.9 km, 2:50). We did fine, running up the hills, and slowing to a walk when necessary, and made it to the first aid station (King’s Mtn) about ten minutes faster than I had estimated. I had added an antioxidant tablet (vitamins A, C, and E) and Nuun (for electrolytes) to my water bottle on the way up. (Apparently all the oxidative stress from running generates free radicals that deplete plasma peroxide neutralizing capacity—See for example, the review “Vitamin C for preventing and treating the common cold,” a review of 29 trials involving some 11,000 participants which, while finding minimal effects in general populations, found significant benefit of Vitamin C supplementation in “persons exposed to brief periods of severe physical exercise and/or cold environments.” See also, “Antioxidant supplementation prevents exercise-induced lipid peroxidation, but not inflammation, in ultramarathon runners.”) I added Conquest to the mix at the aid station and guzzled some Coke (for the caffeine and sugar), and tried to choke down a couple of Cliff blocks. There followed the undulating Skyline Trail, deceptively difficult and seemingly unending, before reaching Bear Gulch aid station in 2:30 (well ahead of the cutoff time—I was so thrilled, since our training runs were not so successful). I used one Gu before this aid station, though it’s unclear whether it did any good. By this time, the speedy 35K runners who started 30 minutes after we did had started to pass us—showing us how it is supposed to be done.

The descent into Wunderlich was an enjoyable respite, even though the trail is rough in places and my quads were starting to complain after we’d descended about 1000 feet. We met the front runners heading back up, smiling and making it look easy, and I just tried to keep it steady and not trip or sprain an ankle or something. I trudged back up the hill munching on my sandwich as best I could (it’s hard to eat solid food when there is no saliva!) and washing it down with my antioxidant/electrolyte supplemented sports drink. I conserved energy and fought off an urge to pull over and sleep, and put in some halfhearted jogging at David’s urging. We made it back to the Bear Gulch aid station (33k) by 4:30, and plunged back onto the Skyline Trail for the return trip. The next descent on the Chinquapin trail was heavenly, but they routed us back up the Dean trail (another slow-to-a-walk stretch) before flying down the road to the finish.

I tried to keep up the pace throughout the race, but after a few hours, my body seemed willing to function only at its solid aerobic level (AKA slow). For example, in the descent into Wunderlich, I averaged something like a 9 min mile pace at a HR of 145–150; while during the descent in Huddart I averaged a HR of 140 at the same pace, at least as far as I can tell from my Garmin data, in contrast to the initial part of the race.

What about nutrition during this race? We started out with a Vespa sample that Peter Defty gave us at the Zombie Runner store opening. I supplemented somewhat with carbs (2 Gu’s total, half a ham sandwich, handful of potato chips, few small cups of Coke, sports drink with sugar). I figure since I was pushing into the glycolytic realm (judging by my generally heavy breathing and high heart rate—at least initially, later on I was too tired for that nonsense and HR stayed mostly below 150), I may well be limited by glycogen depletion and some carb supplementation could help. I don’t know that it does, but I did it anyway. David did the entire race on essentially no carbohydrate, using his home-brew protein shake, this time based on coconut milk instead of cow’s milk; he has become a firm believer in running on fat as fuel. Certainly his energy level was more constant than mine (I really wanted a nap on the way back up Wunderlich), but it’s not clear whether that was because I was pushing my limits harder than he was, or his nutrition was superior. I do know that some food is necessary—I’ve experienced nausea with no food (which could, however, be controlled with just a little chicken broth), but I’m not convinced that Gu’s and sugar are really all that helpful.

So what changed? How did our times get better? Since we’ve been doing ultra runs, the weight loss has stalled. I think that some fat loss is still occurring, and there is increased muscle and blood volume and sometimes even swelling and water retention that accounts for some of the stall. But as there has been no further weight loss, that cannot be the reason for improvement. Since the Firetrails 50 miler and SF One Day, we decided it was time to focus on some basic running skills, and actually “train” on occasion. Having run track as a sprinter in my youth, I knew enough to design some simple intervals to see what various paces feel like. It was a pleasant reminder to feel what a 7- or 8-minute pace is like again, and strangely addictive (I want to keep doing it, even though I can’t keep it up for long, unfortunately). We’ve started timing our runs so we can see what might be working, and are including some fartlek segments and some hill sprints in addition to occasional track workouts. I think the most important improvement has come from running on roads, since trail runs inevitably make me stop to walk, if only to admire a beautiful view, or for hills, while road running provides fewer interruptions, allowing you to work on cadence and breathing and consistency, what I’ve been sadly lacking.
So we’ll keep it up and see where it goes!

Slowing with Age?

2008-11-07T07:44:00.000-08:00

We started our current diet 10 months ago in an attempt to regain our health and vitality and lose some of the weight that had crept on over the last few years. We appeared to be developing signs of metabolic syndrome despite our frequent hikes, and it was time for more drastic measures. We love the outdoors and hiking, so it was natural to combine hiking/jogging with the low carb diet we began last January. Initially, we did much the same routes as we’d been doing on our casual hikes for the last two years. We gradually increased the challenge of our outings, trying to find ways to connect different parks, no longer being satisfied with the ~8–11 miles available in most parks. At first, these longer outings seemed long and took a lot of time: 12, 15, 18 miles. I experienced my first nausea during and after an 18-mile run/hike (with a couple of thousand feet of elevation change). That just made me mad and I wanted to tackle it again, this time with a bit of food to see if the nausea could be prevented (it worked). Then on a whim, we did our first 50K (Headlands 50K—cool but very hilly), and got seriously addicted to ultra events and pursuit of improved fitness. The first was slow (8.5 hr), which again made me mad and determined to do better. The second (Stevens Creek 50K—see Mark Tanaka’s race report) was worse for me at least (9.5 hr, but very hot and hilly, very low finish rate), though David tolerated the heat much better and did quite well (~7 hr). The third was getting better, but still unacceptably slow (Skyline-to-the-Sea: 7 hr, and net downhill. See Scott Dunlap’s race report). Our fourth ultra was the Firetrails 50-miler which took 12 hours (at least, not a slower pace than previous races; see Jean Pommier’s race report ). Undeterred, a couple of weeks later I ran 49 miles (again in 12 hours at the SF One Day—another painful story).

So why so slow? I’m 52 years old, and seem to have lost much of whatever speed I ever had (a middle of the pack sprinter in high school and college). I was on track for a 3:20 marathon before a calf injury slowed me down—PR of 3:27), now 25 years ago. Just how slow must I be now? Is it possible for a person to regain the health and vigor they had when they were younger? This is the grand experiment, and may fail badly, but that’s the question. Can I get back what I once had? Can I get better? Do I have to be resigned to being old and slow? Can I improve my health while I do it?

So it seems it’s time for some more serious training. We’ve started doing small interval workouts on the track (a few 200s, 400s and 800s) and some tempo runs, just to try to jog the memory of those quiescent fast twitch muscles (no pun intended). I was dismayed to realize that I’ve lost all sprint speed, and running up on my toes feels like I’m going to spazz out and fall on my face. Just doing 400s at an 8-minute-mile pace seems fast at this point. I’m hoping that will change, but how to improve?

Recently, I came across a link to a blog I haven’t discovered before, with an interview with Dr. Maffetone about training for endurance events that was quite interesting. He’s the inventor of the 180 rule (basically subtract your age from 180 to calculate your maximum aerobic heart rate [HR]). According to this method, you train at a level that achieves the desired HR, and you naturally speed up even though you maintain this level of effort, as you train your body to use fat as fuel. In the interview, he describes how he discovered this method basically by measuring respiratory quotients to determine at what HR fat burning occurred as opposed to carbohydrate burning. According to Dr. Maffetone, anaerobic training can be implemented after base aerobic training, in interval workouts or races, then followed by more base training.

I was intrigued and read some of the other advice on his website (sign up for a free membership). His nutrition advice really surprised me as well—another low carber of sorts! He advocates cutting out all refined carbohydrates, much the same advice of the cardiologist Dr. William Davis who is working hard with his patients to prevent and reverse their atherosclerotic disease.

It’s possible that we’ve already achieved a good grounding in aerobic (fat burning) ability, and that now would be a good time to work on speed. Maybe a good test would be to run a regular road marathon to at least get a good baseline number on my starting point. We’ll have to see how it goes…

Carbohydrate Needs of the Endurance Athlete

2008-11-02T14:16:00.000-08:00

There is increasing recognition among endurance athletes that at least some fat and protein consumption is beneficial for athletic activity extending beyond about 3 hours. Further, most athletes understand that increased protein consumption post-event is valuable for speeding recovery and reducing discomfort in the following day or two. But most still insist that you
absolutely need plenty of carbohydrates before, during, and after the activity to achieve peak performance, to avoid “crashing” or “bonking,” and to recover quickly. Aid stations are typically stocked almost exclusively with carbohydrates, especially sugars (jelly beans, cookies, M&Ms) and simple starches (potatoes, potato chips, pretzels, gels), with the addition of some limited fats and protein only in the longest events. I’d come to increasingly suspect that this advice is probably wrong, and especially wrong for anyone who has adopted a low-carbohydrate diet and made the physiological adaptation to fat-burning to fuel exercise. I can now add my own anecdotal experience.

I have been restricting my average carbohydrate intake to an estimated 20% or so of calories for about 10 months now. At the same time I have been increasing my exercise level and capability substantially, to the point where I have now completed several 50K running events and one 50-mile event. At first, running seemed harder without the usual high level of carbohydrate intake, but over a few weeks it got steadily easier until fairly suddenly it was much easier. I was able to run uphill again (which I hadn't been able to do for a while); I found my routine breathing rate during comfortable sustained running had slowed by at least a third; I could easily go longer without any food intake besides water.

Nevertheless, for my first 50K event, I consumed more like a 50% carbohydrate meal the night before, and consumed the usual assortment of provided aid station food, avoiding only the simple sugars. The running went well enough, though my weight jumped a few pounds the next day and took three or four days to return to “normal.”

Since then I have been steadily cutting back on carbohydrate supplementation during the run. I did the 50-miler on mostly protein and fat with only a modest amount of carbs thrown in. Then I tried a strict low-carb 50K run, using only a “protein shake” (my own brew of whey protein, soy protein, milk, cocoa, almond meal, and walnut oil) for the entire distance. It worked great! I had steady energy throughout the event (no ups and downs) and was still feeling strong at the end to the point where I did not participate in the post-event food and was happily running around on the beach where the event ended. (The day-after weight gain still occurred; apparently that's not a carbohydrate effect.) So my conclusion is that all this carbohydrate is not needed for successful endurance!

There’s still a question of peak performance. Do you need the carbs and the associated blood glucose spike to do your absolute best? Can you go faster with carbs than without? Does it matter if you’re planning short events (sprints, strength events, etc.) rather than longer endurance events? I don’t know, but I’m increasingly favoring the hypothesis that you don’t actually need much carbohydrate at all once your body is adapted to using fat as its primary fuel.

There are at least a handful of papers related to this topic. These papers all support the idea that only limited amounts of carbohydrates are necessary or even desirable for endurance athletes. See, for example:

Larson-Meyer et al., “Effect of dietary fat on serum and intramyocellular lipids and running performance,” Med Sci Sports Exerc. 2008 May;40(5):892–902 reports 3-day crossover trials of endurance trained runners with low fat (10% fat LFAT) or medium fat (35% fat MFAT), and concludes that “despite approximately 30% lower IMCL [intramyocellular lipids] 0.220±0.032% LFAT, 0.316±0.049% MFAT; P = 0.045) and approximately 22% higher muscle glycogen stores at the start of performance testing (P = 0.10), 10-km performance time was not significantly different following the two diet treatments.” Lipid profiles suggestive of cardiovascular disease were associated with the high-carbohydrate-low-fat diet, and the authors concluded that “even short-term consumption of a low-fat diet may unfavorably alter serum lipids, even in healthy, endurance-trained runners.” (Note that this study did not allow time for adaptation to the different diets, so glycogen and lipid levels in the muscle cells are due only to the acute diets tested);

Vogt et al., “Effects of dietary fat on muscle substrates, metabolism, and performance in athletes,” Med Sci Sports Exerc. 2003 Jun;35(6):952–60, which studied the effect on trained athetes of a high-fat (53% fat) or high-carbohydrate diets (17% fat) for 5 weeks in a randomized crossover design, found that maximal power and vO₂-max during an incremental exercise test to exhaustion were not different between the two diet periods, total work output during a 20-min all-out time trial (298±6 vs 297±7 W) on a bicycle ergometer as well as half-marathon running time (80 min 12 s ± 86 s vs 80 min 24 s ± 82 s) were not different between HF and LF. Blood lactate concentrations and respiratory exchange ratios (RER) were significantly lower after HF than after LF at rest and during all submaximal exercise loads. The authors concluded that “muscle glycogen stores were maintained after a 5-wk high-fat diet period whereas IMCL content was more than doubled. Endurance performance capacity was maintained at moderate to high-exercise intensities with a significantly larger contribution of lipids to total energy turnover”;

Lambert et al., “High-fat diet versus habitual diet prior to carbohydrate loading: effects of exercise metabolism and cycling performance,” Int J Sport Nutr Exerc Metab. 2001 Jun;11(2):209–25. No changes were observed in circulating glucose, lactate, free fatty acid (FFA), and b-hydroxybutyrate concentrations during exercise. However, mean serum glycerol concentrations were significantly higher [indicating mobilization of fat stores with glycerol release] in the HFD-CHO trial. The HFD-CHO diet increased total fat oxidation and reduced total CHO oxidation but did not alter plasma glucose oxidation during exercise. By contrast, the estimated rates of muscle glycogen and lactate oxidation were lower after the HFD-CHO diet. The HFD-CHO treatment was also associated with improved time trial times (29.5±2.9 min vs. 30.9±3.4 min)[150 min cycling at 70% vO₂-max followed by a 20 km time trial] for HFD-CHO and CTL-CHO. They conclude that “high-fat feeding for 10 days prior to CHO-loading was associated with an increased reliance on fat, a decreased reliance on muscle glycogen, and improved time trial performance after prolonged exercise”;

Leddy et al., “Effect of a high or a low fat diet on cardiovascular risk factors in male and female runners,” Med Sci Sports Exerc. 1997 Jan;29(1):17-25, which notes that “restricting fat intake may compromise endurance performance and that increasing fat intake may improve endurance performance,” and concludes that “a 42% fat diet maintained favorable CHD risk factors in female and male runners whereas a 16% fat diet lowered Apo A1 and HDL-C and raised the TC/HDL-C ratio”;

Horvath et al., “The effects of varying dietary fat on performance and metabolism in trained male and female runners,” J Am Coll Nutr. 2000 Feb;19(1):52–60, which concludes that “runners on a low fat diet consume fewer calories and have reduced endurance performance than on a medium or high fat diet [and] a high fat diet, providing sufficient total calories, does not compromise anaerobic power.”

Practical Low-Carb Diets

2008-10-06T22:35:00.000-07:00

There’s a lot of hype on all sides (and there are many more than two) of the low-carb diet wars. Unfortunately, many of the arguments and recommendations are based on bad science or even no science at all. Too many dietary recommendations have been based on “expert” pronouncements rather than sound scientific data and rigorously tested hypotheses.

We’ve been reading about nutrition and making our own dietary decisions based on that reading and our personal experience for about nine months now—hardly long enough to become real experts, but long enough to have developed our own best guesses as to what seems to be right, at least for us.

So here is “David and Cynthia’s Guide to Low-Carb Eating.” Basic principle: cut back drastically on the simple starches and sugars that have become ubiquitous in first world diets (of all ethnicities and nationalities). Period. End of story. Beyond that, the details are secondary and serve mostly to provide guidance as to how to achieve that goal. Some details also have secondary health effects that are important if still secondary.

First, of course, you need to recognize what the major dietary sources of simple starches and sugars are. Sugar would seem to be obvious, but there is a large misinformation campaign out there on the part of advocates of various sugar substitutes that can trip up the unwary. A simple rule of thumb is that if it tastes sweet and isn’t a non-nutritive sweetener (sucralose, saccharin, aspartame, etc.), it’s sugar and needs to be minimized in your diet. Calling it “evaporated cane juice” is just a silly marketing ploy. Honey, rice syrup, maple syrup, etc. may have additional valuable trace nutrients, but the macronutrient is still sugar. Even maltodextrin, which is a long-chain sweet-tasting molecule, that gets classified as a starch instead of a sugar, is still readily broken down by the body to simple sugars (that’s why it is added to sports drinks and “gels”). Don’t be fooled by “100% juice” products and similar products with added fruit juice that use apple, pear, or white grape juices to provide sweetness. These are just alternative sources of sugar; apple and pear are particular bad in that they contain a high percentage of fructose. If you must sweeten your food, use whichever of the artificial sweeteners that you tolerate the best. We don’t really like any of those that we have ready access to and generally opt to simply make do with a lot less sweet taste in most of what we eat, but we do use Splenda (maltodextrin and sucralose) when we feel we need a sweetener. (There are at least a couple of potentially better non-nutritive sweeteners with less objectionable taste and aftertaste: Stevia-based products like Truvia and Acesulfame-Potassium-based products like Sweet-One. These sound promising in written descriptions, but we haven’t yet tried them and don’t presently know where to buy them affordably in bulk. Ordinary table sugar and high-fructose corn syrup remain the sweeteners that are commonly sold at much the lowest net price [price per unit of sweetness].) You also need to limit your intake of fruit, especially juices and dried fruits which tend to encourage large servings. All fruits contain significant amounts of sugar in addition to all the nominally healthy micronutrients (vitamins and minerals) that they are often advertised to contain.

Simple starches include starches from grains and tubers. Most ubiquitous in the American diet is wheat starch (flour, bread, etc., etc.). Rice, oats, barley, quinoa, rye, and other grains aren’t much better (despite the advertised heart-healthy characteristics of oats, for example). Potatoes are the most common tuber with a lot of simple starch. These starches are quickly broken down by the body into simple sugars.

Other foods also contain carbohydrates. Many vegetables contain significant amounts of carbohydrates as either starches or sugars or both. Root vegetables such as carrots and legumes such as peas and beans tend to contain more carbohydrates than leafy green vegetables (spinach, kale, lettuce, etc.) and cruciferous vegetables (broccoli, cauliflower). However, for the most part, you are much less likely to overeat starches from these vegetables, and you get plenty of other good nutrients. On balance, we don’t think you need to particularly avoid the higher-carb vegetables, although some recommendations such as those for the “induction phase” of the Atkins diet, have you minimize their consumption as well.

Dairy products contain carbohydrates too. Lactose is a disaccharide of glucose and galactose, and a typical 8 oz serving of milk or yogurt contains 9 to 17 g sugars (depending on how much dry milk was added or how much fermentation occurred). Hard cheeses generally contain much less carbohydrates. Casein is reputed to induce insulin release, which of course defeats the purpose of the low carb diet: to minimize blood insulin as well as glucose, so that the fat cells are releasing fat for use as fuel, rather than sequestering it safely away for long term storage (making us fatter). But that doesn’t stop us from using dairy products which also contain a lot of protein and fat; we aren’t interested achieving zero carb intake or in seeing how fast we can lose weight, but rather in eating a diet that we can sustain indefinitely to reach our target weights and maintain it, without giving up in screaming frustration and deprivation. We like our dairy products! Curiously, the “paleo diet,” which is a fairly low carbohydrate diet, proscribes dairy products but encourages consumption of a lot of fresh fruit. We remain skeptical of such a recommendation unless you happen to be lactose intolerant.

You probably shouldn’t try to cut out all carbohydrates. How low you need to go to be practicing a “low-carb” diet is something that is not well understood. Our own feeling (read “guess”) is that there is no magic threshold, and the answer may vary widely from individual to individual. Certain individuals seem to be able to thrive on a high-carbohydrate diet for a lifetime, while others clearly do much better on much lower levels of carbohydrate consumption. It probably depends on both your genetics and on how active a lifestyle you lead. For us, cutting carbohydrate consumption to under about 20% of calories seems to work well. Some studies have shown significant benefits of lesser reductions. Others advocate more extreme reductions in carbohydrates. If your goal is to get under 20%, then you don’t need to worry too much about starches in vegetables, and it’s even OK to “cheat” a bit. Go ahead and eat some sweet dessert occasionally or even eat that piece of pizza at the party where no low-carb alternatives are offered. Just try to keep the averages down.

The Atkins organization recommends starting out a low-carb diet with an ultra-low-carb induction phase (less than 20 g per day) for a couple of weeks followed by a low-carb phase which is then further relaxed after target weight levels are reached. We don’t see any clear evidence that such a phased approach makes any particular sense or has any particular benefit other than shock value and initial rapid weight loss to keep motivation high. It may be true that the abrupt change induces fat adaptations more quickly, but we know from studies that it takes at least 2 weeks to biochemically adapt (see Phinney (2004)), and a more gradual adaptation may be less stressful for some people. It seems simpler, and probably just as effective, to simply change to a new long-term diet and stick with it. Too many people treat the Atkins diet as a temporary weight loss diet that can be abandoned after the weight loss is achieved. These people regain much or all of the weight lost. It’s not clear that repeated Atkins inductions are as effective either.

A couple of further remarks on types of carbohydrates are worth making. First, we reiterate the important difference between fructose metabolism and glucose metabolism (see our earlier blog entry on fruit). While fructose produces a lower glycemic response, it’s probably a lot worse than glucose from a weight management point of view. Most sweet foods, including most fruits, actually have about equal amounts of fructose and glucose, so there’s not a lot you can do to minimize fructose in favor of glucose, but if you do have a choice, don’t go for high-fructose foods.

Fructose is metabolized by the liver into triglycerides which are then easily stored as fat. The path from glucose to fat is at least a little more convoluted, but it’s clear that triglycerides track carb intake, a fact that is shocking to most people since we’ve been taught that fat intake is what drives triglyceride levels high. However, this is not so: ingested fat is transported in chylomicrons and is preferentially absorbed by the body tissues, and so disappears from the blood quickly (within an hour typically). Triglycerides, in contrast, are produced by the liver in response to fructose and carb ingestion and released into the circulation for hours after each carbohydrate containing meal. Hence high carb meals result in all-day (and all-night) elevated triglycerides. That’s why people on low carb diets have very low triglyceride levels compared with people eating “normal” high carb diets, despite proportionately higher fat intakes (see, for example, Table 3 of Gardner et al., 2007 and Parks and Hellerstein 2000).

Second, certain starches have come to be known as “resistant” starches that are metabolized more slowly and generate less of a glycemic response (blood glucose spike). For the most part, these are the vegetable starches, and perhaps most importantly, the legumes, in particular. This provides a justification for the standard practice in low-carb cooking of replacing grain flours with legume flours such as soy flour or chickpea flour. These bean flours have less carbohydrate than wheat flour, but still have significant amounts. The fact that the starches in beans are digested more slowly seems to make them less prone to producing a blood glucose spike and less prone to being converted to stored fat. Speaking from personal experience, this substitution works quite well, at least from a nutritional point of view. You can do a one-for-one substitution of soy flour for wheat flour in many recipes. Those foods (like bread) which depend on wheat gluten to provide mechanical strength (elasticity) to a dough don’t work too well with a 100% substitution. In these cases, we use part soy flour and part gluten flour (wheat gluten separated from the wheat flour—use about ¼ to ⅓ wheat gluten by volume). Wheat gluten is mostly protein and is safe to use in low-carb cooking (unless, of course, you happen to be sensitive or allergic to it). You can also effectively substitute fiber such as wheat or oat bran and almond meal or other grated nuts for part of the flour.

What about “whole” grains and fiber? Don’t we need a lot of fiber in a healthy diet? Aren’t whole grains good for you? Not as far as we can tell! And we have no personal bias against whole grains. We like to eat them. Our current best hypotheses regarding whole grains and fibers:
1. To the extent that fiber is good for you it is in the context of high-carbohydrate diets only. If nothing else, adding fiber tends to fill you up with more non-nutritive filler, and you eat less simple starch.
2. Fiber probably also promotes intestinal health in the presence of a large carbohydrate load in the gut. Without the large carbohydrate load, it is less clear that you actually need a lot of fiber. Populations that eat no carbohydrates manage just fine with little or no fiber.
3. The alleged binding of starch to fiber to slow starch metabolism seems to be a myth. The measured glycemic response to whole grains is identical to that of equivalent amounts of refined grains. Perhaps if you swallowed genuinely “whole” grains that are still fully encapsulated in fiber (don’t chew!), you might slow the starch metabolism, but otherwise the starch you do consume is still processed quickly.
4. You may get more trace nutrients from whole grain than from refined grain, but there are better sources for those trace nutrients.
5. The same goes for fruit! Fruit contains a lot of fiber and significant trace nutrients, but it comes with too large a dose of sugar.
6. Fiber is not completely non-nutritive. It is at least partially digested by bacteria in the intestines, and seems to lead to production of short chain fatty acids, which are absorbed to varying extent. What that means nutritionally, I’m not sure. There’s probably not enough net usable calories in fiber to be of much significance. On the other hand, the short chain fatty acids are elongated in the liver to increase the net triglycerides.
7. If you want to eat fiber, go ahead! Focus on vegetable sources which come with a lot higher doses of trace nutrients anyway. It’s probably OK to add wheat or oat bran to your baked goods, but do it because you like it, not because it makes you feel virtuous. But be aware that sources of phytic acid such as grains are known to reduce absorption of minerals and may contribute to osteoporesis and other deficiencies.
8. There aren’t any significant nutritional differences between soluble and insoluble fiber that we’ve been able to identify.
9. When you read nutritional labels, “total carbohydrates” generally include any fiber in the food. It’s probably OK to subtract out the fiber as being largely non-nutritive. But beware of claims of “zero net carbs” or similar for foods that obviously contain simple starch. You can only subtract the fiber content from the total carbohydrate content to the extent that the total includes the fiber in the first place. You can’t add fiber to offset the presence of simple starches.

What about fuel for exercise? Don’t athletes need carbs to provide short-term fuel for peak performance? Probably not! This one is fairly complicated to sort out in detail, though. If you are accustomed to a high-carbohydrate diet and switch, you will likely feel that you can’t get peak performance or even satisfactory performance from your muscles for some period of time while the body’s endocrine system and metabolism readjusts to use the fuels you do provide. For instance, there is evidence that a high fat diet increases mitochondrial biogenesis (through activation of PPARdelta) and induces muscle type switching from fast twitch to slow twitch (from glycolysis to fat burning), and importantly, may induce resistance to obesity. This adaptation period of time may last for 2–6 weeks depending on your particular circumstances, but you will get through it and eventually find that you can switch over to fat burning. The evidence supports low carb diets for endurance sports at least, as fat burning enzymes and mitochondria are increased resulting in carb sparing for when you really need it. Is “carb loading” before competition useful? Probably not, again! Making sure your muscles are fully loaded with glycogen may be valuable for maximal anaerobic efforts and sprints, and possibly for longer events, but do it by tapering your training, not by carb loading. What about right before or during the event (especially for events of more than 2–3 hours duration)? This one is less clear. It’s possible that you can achieve a personal best performance with the aid of some extra quick-release fuel from carbohydrates, but even that could be a myth. While we find that, now that we are adapted to low-carbohydrate-fueled exercise, we can go longer without any refueling, but we still eventually need to refuel. We still tend to use carbohydrates, because that’s what’s usually available. But we do try to avoid or at least minimize the simple sugars and make sure we get some protein and fat, too. We haven’t yet tried to maintain a high level of exercise over periods of more than four hours using mostly fat or fat and protein as fuel. Right now, we’re inclined to think it will work just fine, although it may be necessary to start refueling a little sooner to compensate for slower digestion. Post-event nutrition is important, too, but the key need then appears to be added protein to speed muscle repair and recovery, not carbs.

So then, if you’re not eating carbs, what do you eat? The short answer is fat! While you may not have been eating enough protein on your high-carb diet, it’s pretty hard to replace carbs with only lean protein, and can make you sick (the liver can’t dispose of that much ammonia). As a practical matter, a low-carb diet is almost always a high-fat diet. Anyone who tries to have it both ways by continuing to recommend restricting fat consumption while supporting reduced carbs is deluding themselves. It’s essentially a prescription for extreme total calorie restriction, and no one should maintain severe calorie restriction for more than very short periods (and probably not even that).

What kind of fat should you eat? That’s a much harder question, and we think it will be a few years before we have a good well-researched answer. From a simple macronutritional point of view, it appears that it probably doesn’t matter too much. It’s much more important to your health that you replace calories from simple sugars and starches with calories from fat than that you carefully choose which fats to eat. That’s the curious thing about how the popular press and the attention of the public at large focus on nutritional issues. Millions of people will start taking the latest supplement based on flimsy evidence that it slightly improved some condition or other in a handful of test subjects while completely ignoring the basic macronutrient imbalance in their diets. We will take the micronutrient research a lot more seriously when we finally get the macronutrient recommendations properly understood and straightened out.

That said, it is worth commenting on what some of the major issues are with regard to fat choices. Most obvious, of course, is the saturated fat controversy. As nearly as we can tell, there is no good scientific evidence that saturated fat is bad for you despite decades of pronouncements that it is. (This subject is too big and too controversial for one or two references; perhaps we'll write more about it in the future.) Higher consumption of saturated fat may be correlated with elevated blood lipids (particularly HDL, but that's "good" right?), but those elevated blood lipids are not well-correlated with health problems such as coronary artery disease. The assumption that saturated fat is bad is so ingrained in the culture and training of our “experts,” that one must read all related studies very critically, and understand that in the presence of excess carbohydrate, triglycerides will be elevated in most people, and will be formed primarily of saturated fat. You often find that authors are struggling to reconcile apparently contradictory results with the assumed “truth” that saturated fat is bad. Looking critically at the actual data often shows that, if there is any clear difference at all, the test subject consuming more saturated fat were better off on whatever measure was being monitored. So go ahead and enjoy your butter and meat fats, but limit the carbs when you do. Use lard if you like.

For a while we were taught that the more unsaturated a fat was, the better. Then we learned that omega-6 polyunsaturated fats are bad and so maybe monounsaturated fats were as good or better. Hydrogenated vegetable fats were initially considered a “healthy” substitute for the evil lard and butter, but were later found to be worse. “Trans-fats” have recently become taboo. More recently, there is concern that polyunsaturated fats are easily oxidized and implicated in inflammatory atherosclerosis processes ("oxidized LDL"). We are now focusing on the relative amounts of omega-3 and omega-6 fatty acids in our favorite fats and our overall diets. So what’s a high-fat eater to do? In the absence of good science, we still have to eat! Here’s our current working recommendations and hypotheses (aka best guesses):

1. Go ahead and eat as much saturated fat as you like. It won't become oxidized and will increase HDL levels.
2. Avoid trans-fats and hydrogenated vegetable fats.
3. We tend to favor olive oil, then canola oil, then nut and seed oils in our cooking right now, but we’re open to new data that might shift the emphasis around. We've been tempted to try the rendered goose fat available in our local market, but haven't yet. We’re likely to choose an oil based on its performance or taste characteristics as much as anything and to favor cheaper oils when performance or taste don’t dictate a clear choice.
4. Omega-3-rich fats and oils are probably desirable when and where you can get them. Wild oily fish such as salmon and mackerel are probably the best sources. (Farmed fish may not be, depending on the feed that is used.) If you want to go with supplements, use fish oil or cod liver oil by preference over flax seed. Flax seed and flax seed meal or oil are probably the best readily available vegetable sources of you prefer them or want to use them in addition, but it’s not clear how much of the omega-3 fats in flax are even converted in our bodies to the desirable forms.
5. “Free-range” and “grass-fed” meat probably has “better quality” fat than the factory or feed-lot (corn-fed) equivalent. You may also find that it tastes better. It’s also typically a lot more expensive if you’re not raising your own. If your budget allows, and your local stores offer it, by all means go for it, but don’t worry too much if you find yourself eating mostly the cheap stuff.

Getting the macronutrients generally right is still the most important thing to do. Since fats become a dominant source of nutrition in a low-carb diet, it is apparent that the choice of which fats to eat must become a close second. Absent clear scientific evidence to support a strong emphasis on one or two sources of fat, the best we can conclude for the moment is that you should diversify and consume a least some fat from a lot of different sources.

So what about protein? It’s pretty clear that you do need some protein, and in particular, you need protein that contains certain “essential” amino acids that the body cannot manufacture for itself, including vitamins such as B12 that are difficult to find anyplace else. Animal protein (especially organ meats) is a very rich source of most vitamins (except folic acid and vitamin K). Chronic protein and vitamin deficiency can cause severe malnutrition, poor muscle development, and premature aging. Vegetarians need to be particularly careful since good vegetable protein sources tend to be limited and tend to have much lower protein and vitamin content than meat and fish. From a purely nutritional point of view, humans aren’t really designed to be vegetarians, though if you choose to be so on moral or religious grounds, it is still possible to avoid malnutrition as long as you make sure you get enough of the right proteins and supplement to avoid vitamin deficiencies.

You will also find warnings against eating too much protein, particularly if you have impaired kidney function. For most people, this is not a serious concern in that it’s fairly difficult to actually eat too much protein. (See, for example, Martin et al. (2005).) Perhaps, if you tried to cut both carbs and fat out of your diet, then you could do it, but most reasonable ad libitum diets emphasizing fat and protein are not likely to give you too much protein.

Obviously, there’s no good reason to follow the low-fat crowd to the leanest cuts of meat. You don’t have to remove the skin from chicken and turkey of you don’t want to, and go ahead and leave your beef, pork, and lamb untrimmed if you like the fat. You can also eat cheese and other dairy products for protein as well as eggs, nuts, seeds, and tofu. These tend to come with a generous serving of fat, but that’s OK.

If you’re an athlete, then you may need to consciously increase your protein intake to help build and repair muscle. If you have trouble getting enough protein from your standard dietary sources, you can supplement by using either whey protein or soy protein powders. Whey protein is probably the better choice from a protein quality point of view, and there is some concern that soy protein, if consumed in large quantities, may provide excessive hormones. We use both with an emphasis on the whey protein. Whey protein tends to be sticky and gooey (at least when concentrated), and soy protein isolate behaves more like a flour; both are largely tasteless by themselves. They can be added to anything from eggs to baked goods and drinks. They are often packaged for retail sale in various adulterated (and overpriced) forms with added flavorings and sweeteners. Buy them unadulterated if you can (one on-line source: Honeyville Grain).

One last useful ingredient that we recently discovered is polydextrose. This is a long-chain sugar polymer that is largely indigestible and functions nutritionally like fiber. It is also tasteless (i.e., not sweet by itself). However, it can provide a lot of the mouth feel and body that artificial sweeteners generally fail to do. So far, we’ve tried it in homemade artificially sweetened ice cream and carrot cake with very satisfactory results. (You may need to disperse it in warm liquid first; it tends to clump.) We never met a low-fat ice cream that we thought was worth eating, but as long as you use flavors that adequately mask the objectionable bitterness and aftertaste of your artificial sweetener, you can make a very respectable low-carb ice cream! You can buy polydextrose as a commercial food ingredient, for example, from Honeyville Grain.

We find we don’t really miss most carbs. We don’t crave things like cookies or noodles at all, but occasionally find it necessary to eat a sweet potato or make polenta to quiet the cravings for a few days. It also depends on how much we are exercising. Of late, with our 50+ per week running mileage, it seems less important to cut carbs, but we generally keep them low anyway, compared to the usual endurance athlete's diet). On the other hand, the more we exercise, the less the weight comes off! We're not sure if it's due to eating more carbs or increased cortisol levels from overdoing it of late (three 50K trail races since Aug 23 and a 50 miler planned!).

Energy Balance During Endurance Events

2008-09-01T07:16:00.000-07:00

We are generally strictly recreational runners. Cynthia ran a few marathons some 20 years ago; the longest races that David ever entered competitively were a few 10K events (plus a sprint triathlon), though we’ve also both done quite a bit of race organizational work. On something of a whim, we completed our first 50K race last weekend. The race was in the Marin Headlands, north of San Francisco. It was probably not the best choice for a first 50K, since it involved serious hill climbing (about 7000 ft of total climb spread out over seven “hills”) and rough trails. We were probably not as well prepared as we should have been for such an event, but figured if we could do 18 miles over similar terrain, we should be able to struggle through another 13 miles if determined and prepared for blisters.

Our basic aim was to complete the event in reasonably good condition, and we succeeded admirably, if not speedily, coming in at about half the pace of the first finisher, and very near the back of the pack. Not surprisingly, the last half was more an exercise in keeping going than trying to achieve any speed at all—we walked up all the hills and jogged pretty slowly on the way down. However, we were still mobile at the finish line and had no major injuries or problems. We took two days off and were able to run one of our standard hour-and-a-half hilly runs, feeling, if anything, stronger than usual the third day. On balance, except for the slow pace, we were pleased with our success.

Just so as not to blame our low carb diet for any difficulties, we had a pasta dinner the night before in the traditional “carb loading” style of runners everywhere, and even ate oatmeal for breakfast before the race began. (As it turns out, Cynthia felt worse than usual, whether that was due to the early hour and lack of sleep the night before or to the change in diet, we don’t know.) And of course we tapered our training the couple days before. One advantage of running in an organized race is the periodic aid stations, where you can load up on water, electrolytes, and food such as potatoes, cookies, chips, PB&J sandwiches, so you don’t have to carry liters and liters of fluids and snacks with you.

There were many with the usual runner physiques, slim and wiry, and quite a few older runners, some significantly older than we are, some distinctly overweight, but in strong physical condition nonetheless (better than us it turned out). Certainly many of the people interested in these long events tend to be those that are good at it, with some inherent natural speed and talent. But you don’t have to be inordinately talented to enjoy a long walk/jog through the woods, communing with nature, or challenging your own talents.

The course was every bit as difficult as promised, and about half way through, after the first three monster hills, Cynthia felt “bonked”—low on energy and wondering how to eek enough effort out of her tired legs to get through the rest of the event. In fact, Cynthia thought it was far more difficult than any of the street marathons she ever did—those resulted mainly in increasing pain in the legs and feet, and less of a sense that she could not continue due to the low energy or the weight of her legs. And it took more than twice as long as any marathon she had ever run! A serious testing indeed. Even her lungs feel fried days afterwards.

Description of the event can be found in an article in the Marin Independent Journal, as well as Jean Pommier’s fartherfaster blog.

David clearly was better prepared to maintain a higher level of energy output and likely could have gone significantly faster, but we stayed together for safety, support, and companionship. The fabled Headlands fog never lifted and the cool sea breeze was a blessing. Cynthia doesn’t think she could have made it in normal summer heat. The volunteers were wonderful and supportive: Many thanks!

But the interesting story is really our observations on energy intake and expenditure. Cynthia was reluctant to start eating at the aid stations, because the lump of breakfast hadn’t even passed yet, and why should she need more carbs when the oatmeal was still digesting? She did go for juice and chicken broth (a favorite for cutting hunger pangs and preventing nausea) and a bit of sandwich, but she didn’t feel that anything coming in made much of a difference, except perhaps to allow her to keep going, albeit at reduced pace. And perhaps that is enough, to keep going when fatigue, nausea and assorted pains would otherwise make you stop. We estimate that Cynthia’s total caloric intake during the race was only about 800 kcal—She has never been good at eating while running. We think she drank enough to stay hydrated—not too difficult in the cool conditions.

David’s approach was quite different: he’d quickly down a couple of gels (at 100 kcal each), a couple pieces of boiled potato or bit of banana at each aid station, and drink a couple of pints of sports drink and/or water over the distance between aid stations (about 4 miles apart). His total intake during the race is estimated at more like 3000 kcal.

We attempted to estimate the energy expenditure (as excess over basal metabolic rate) required to complete the race. We did this a couple of ways based on published values for running and walking on the level, and some information on the food energy intake required to sustain a certain level of mechanical work output (you need about 4 kcal of food energy in for every 1 kcal of mechanical work). Our rough estimates are that Cynthia burned about 3500 kcal, and David burned about 4500 kcal during the race. (It felt like a lot more!)

Of course, in addition to the food consumed during the race, we ate more than usual before and after the race. All told, Cynthia consumed about 1000 kcal more than typical, and David consumed about an extra 3000 kcal. If these numbers are anywhere close to correct, Cynthia ran a net deficit of about 2300 kcal, and David a net deficit of about 1500 kcal. Conventional wisdom is that it takes a net surplus/deficit of 3500 kcal to gain/lose a pound of fat, so a strict energy-in-minus-energy-out-equals-energy-stored-as-fat model would suggest that we should each have lost some measurable weight (but under a pound) once we were back to steady-state hydration levels (i.e., by the next morning or so).

So what really happened? Our weights were up a pound or so on race morning (presumably from carb loading the night before). The next morning, David’s weight was up another four pounds; Cynthia’s weight peaked the second morning after, up about three pounds from pre-race levels. Thereafter, the weight came back off over 4–5 days, returning to previous trendlines. The gain was particularly rapid, although the loss was also very rapid if looked at out of context.

Even though we don’t believe in the energy-in-minus-energy-out-equals-energy-stored-as-fat model, we were still surprised to see such a dramatic weight effect and especially to see a significant temporary weight gain as a result of the event. So why did our weight increase? Maybe muscle and ligament damage from overuse results in temporary swelling and fluid retention due to inflammation? Maybe the body fears that you’re going to go out and get dehydrated again, so compensates with some hormonal signals to retain additional fluids? Our appetites were elevated substantially for a couple of days, but not enough to account for the weight gain. Is it psychological or physiological? What about growth hormone and insulin levels after endurance events? Or some other hormone levels? Or were we just seeing the results of a spike in carbohydrate consumption and the consequent increase and decay in carbohydrate-induced fluid retention? (The correlation between carb intake and some amount of increased fluid retention is well-known, particularly in the context of initial weight loss when starting a low-carb diet, although it is less well understood exactly where and why all the increased fluid retention occurs or what the time-constants associated with diet changes should be.)

A week later we ran one of our longer routes—about half the length and time of the race—consuming much more modest total calories in general and carbs in particular. Knowing what to look for, we saw a modest increase in weight the next morning (a pound or so, and more or less within the noise of normal daily fluctuations).

The bottom line? We clearly can’t recommend endurance running as a weight loss aid. One, the energy consumed is just too small!!! It may feel like you’re burning off huge amounts, but the fact is, our bodies are quite efficient, and can perform large quantities of work using modest amounts of fuel. Two, while it is easy to end up with some calorie deficit, it is difficult to do so in a measured and controlled way—the tendency is to overcompensate for a perceived expenditure and negate any losses. Three, with more strenuous expenditures, there is a need to replace not just calories, but also vitamins, protein and electrolytes, etc., to heal injuries and strengthen bones, ligaments and muscles, and restricting food can lead to exhaustion if not serious injury and illness. Four, at least in the short run, there appears to be compensatory fluid retention and weight gain, so don’t think you can go out and burn off a pound of fat in a day and thereby fit into that dress you want to wear!

While, in general, serious endurance athletes report being able to eat more or less unlimited quantities of whatever they feel like eating, more casual or occasional endurance efforts aren’t going to have much effect, and may even tend to show weight gain instead of loss, especially if one erroneously believes one is burning off fuel in excess of actual needs. That said, we did find the experience to be a positive one overall, given our incoming level of fitness (i.e., we weren’t attempting anything too far outside of our level of fitness). We recovered quickly and felt, if anything, stronger and fitter afterwards. We stayed within the recommendation that, when first attempting longer and harder events, one should first just aim to finish and become “comfortable” (or at least, familiar) with the new distance, then try to do it faster. We're still working on it, but further gains may have to wait until we’ve dropped down to more of an optimal weight, and until we’ve undone various metabolic and/or structural damage due to poor eating habits over many years (assuming our present diet is doing so)!

More on the Shape of Weight Loss Curves

2008-08-17T17:25:00.000-07:00

This installment about weight loss will focus on data for David (age 53, height six ft even). By way of background, I weighed about 160–172 lb in college (early 1970s), then tended to be in the 170s in my 20s, 180s in my 30s, 190s in my 40s, following the typical sort of pound-per-year pattern of adult male weight gain. I ballooned to close to 220 at the end of the holiday season at year-end 2007. My weight over the previous 2–3 years had become more erratic, fluctuating from about 205 to 220.

At the beginning of 2008, I adopted a non-calorie-restricted low-carbohydrate diet. If anything, I reversed the Atkins-recommended pattern of an “induction phase” of extremely low carbohydrates followed by a maintenance phase. Rather, I phased out carbohydrates from a previous life of 60% carbs (10% protein, 30% fat) to more like 15% carbs (25% protein, 60% fat) over a month or so by slowly finishing off leftover holiday sweets and breads and then not replacing them. Eating to satiety also occurred with an estimated total daily calorie reduction from about 2700 to about 2100 (all very rough numbers). The resulting weight loss is shown on the graphs of weight versus time (date).

I saw an initial weight loss rate of about 2 lb/wk for the first 2–3 weeks, similar to a typical induction phase. Thereafter the rate of loss dropped off to about 1 lb/wk, slowing perhaps to 0.75 lb/wk. It was starting to look like a possible exponential decay from an initial state to a final state resulting from a step change in diet, with a time constant of 8–14 months depending on what I chose as a likely asymptote. (Until there is measurable curvature in the data, it’s not possible to reliably fit a specific value to the asymptote.) I was trying to model the weight loss as a simple exponential decay, assuming that there was a single step change to account for. This would result in a linear fit on a semi-log plot of weight above assymptote versus time. This exponential approach to an asymptote (slowing of weight loss) might be expected because as body mass decreases, less total caloric intake is required just to maintain the body’s metabolic needs. Without further modifying the diet to decrease calories in, one would expect the weight loss to slow. You can see on the graphs that the data could be fit nicely to either an exponential model (straight line on the semi-log plot) or to a piece-wise linear model (set of straight lines on the linear plot) through July. The exponential fit shown assumes an asymptote of 165 lb. The linear plot has the exponential fit shown in orange. The light blue linear fit is drawn through the data from about February through May. The green line is a piece-wise linear fit with segments for the first two weeks, then mid-January through mid-March, mid-March through July, and a separate line for early-July through mid-August. The dashed dark green lines delimit a ±2 lb tolerance band about the mid-March through July fit line.

By mid to late July, it was still difficult to clearly identify which model fit the data best given the normal daily scatter in the data (even with some care to always measure under the same conditions, first thing in the morning). Certainly, a piecewise linear model where there was presumed to be some sort of “induction” phase for the first couple of months followed by a slower linear weight loss rate thereafter fit the data at least as well as the exponential fit.

Then, around the beginning of August, I was starting to get a cluster of data points that were looking unusually low, even though I hadn’t specifically made any major change in diet or lifestyle that I was particularly conscious of. Now, in mid-August, looking back, one can model the last six weeks of data as exhibiting a linear loss of about 1.5 lb/wk, about double what it had been for quite a while! So much for any simple linear or exponential fit to the data! Where will it go from here? And why? I’m not at all sure. Stay tuned for the next exciting episode!

I probably also eat somewhat less as my weight has decreased, although since I haven’t been keeping a careful food diary, that’s hard to prove. It’s clear that eating more dense calories helps you adjust to eating less food total, since you achieve satiety with smaller piles of food on your plate and fewer second helpings.

So, what’s going on in my life besides the low-carb diet? What could have caused the weight loss to accelerate? Clearly, life is more complicated than simple step changes and rapid return to a new equilibrium or steady-state.

A couple of things that may be different in the last 6 weeks with respect to diet are that I am probably eating a smaller late evening meal (meaning usually no second helpings), and about 3–4 days per week, my breakfast is now a protein shake, consisting of a couple of cups of whole milk with soy protein and/or whey protein plus low-caloric flavorings. My best estimate is that the number of calories in that breakfast is about the same as the typical cheese omelette or similar that I often eat otherwise, but there probably is a shift toward more total protein and less fat in the meal.

I’m now down about 30 lb in 33 weeks. I expect to be able to comfortably lose at least another 10 if not 20–25 lb before I reach a stable healthy weight. I suspect that I have more upper-body musculature than I had in my 20s, which may limit me from reaching my minimum athletic college weight, but I’m not sure. My waist circumference was about 34" in college, increasing to about 38" until recently when it got up to about 41". I’m back down to 36" now, and still have a little bit of a “spare tire.” I expect to get back down to 34". Almost all of my excess weight seems to have been stored as visceral fat in the abdomen and above the beltline for most of my pants—none of the weight gain or loss ever made all that much difference to the fit of most of my clothes, one of the reasons that my pattern of weight gain was rather insidious and easy to ignore. (This is probably true for most men.) Many of the symptoms of metabolic syndrome that I had have now gone away or abated (more on that after the next physical exam.)

Part of what had resulted in the relatively rapid weight gain in the last 2–3 years were some major changes in my life that made me more sedentary after a period of higher activity, along with an appreciative eating audience who enjoyed and encouraged my baking habits. (We have yet to find or develop a new bread recipe that is an acceptable low carb substitute, though we’re making progress.) One always tends to reduce eating more slowly than one reduces activity, so in principle, the weight could have accumulated simply because of excess calories. (Or was it excess carb consumption?)

In the last few years, I have eaten more of my calories late in the day, if that makes any difference. (I think it did, if for no other reason, than because I was more likely to need extra snacks to hold me until a late evening meal. Previously, I ate an earlier dinner, so I didn’t need an afternoon snack, and rarely ate anything for several hours before sleeping.) But I was hardly leading a couch-potato lifestyle while gaining weight. I was typically running at least 25–30 mi/wk on hilly terrain, if not always very fast. The running certainly seemed to be getting harder as I got either older or heavier or both. For my weight (averaging about 210 during this time), this amount of exercise should translate into 3300 kcal expended each week, or an average of 472 kcal/day (assuming no additional caloric expenditure for the hills—my best estimate is that our particular hills added another ~60 kcal/day). I estimate I was eating an average of about 2700 kcal/day during this time, which is about as much as the Runner’s World diet page says is needed to maintain my weight with only light exercise. Without getting into a critique of the Runner’s World diet recommendations (another posting), I should not have been gaining weight on this amount of calories with the amount of exercise I was getting!

Not surprisingly, my running ability has improved significantly with 30 fewer pounds to cart around. My breathing is easier and slower. My heart rate is slower and recovers faster. I can run uphill again, where I previously pretty much slowed to a walk most of the time. Longer runs (12–18 miles) don’t wipe me out anymore. I’m probably logging closer to 40 mi/wk than 30 mi/wk right now, though I’m still not going to win any races.

Regardless, what I am doing works! I’m not struggling at all to lose weight. I never feel like I am starving myself, and except for the usual carb temptations in the world at large, I am finding the diet easy and comfortable to live with and sustain.

Exercise and Weight Loss

2008-07-30T16:18:00.000-07:00

A friend sent me a link to this just published article about weight loss and exercise. According to the abstract of the actual scientific paper (I couldn’t access the full text), overweight and obese women (201 subjects, aged 21–45 years with BMIs from 27–40) were assigned to 1of 4 behavioral weight loss intervention groups. They were randomlyassigned to groups based on physical activity energy expenditure(1000 vs. 2000 kcal/wk) and intensity (moderate vs. vigorous).Participants also were told to reduce food intake to 1200 to 1500kcal/d. (Doesn’t sound to me like an easy caloric intake to achieve on any of the usually recommended weight loss diets.)

According to the abstract, weight loss did not differ among the randomizedgroups at 6 months (8–10% of initial body weight) or 24 months(5% of initial body weight) follow-up. (In other words, calorie restriction on whatever diet they were using was not sustainable; or starvation is not fun!) Post-hoc analysis showedthat individuals sustaining a loss of 10% or more of initialbody weight at 24 months reported performing more physical activity(1835 kcal/wk or 275 min/wk) compared with those sustaininga weight loss of less than 10% of initial body weight (P < .001).

The authors concluded that the addition of 275 mins/wk of physical activity,in combination with a reduction in energy intake, is importantin allowing overweight women to sustain a weight loss of morethan 10%. They also concluded that interventions to facilitate this level of physicalactivity are needed. In other words, the current recommendations for exercise to achieve and maintain weight loss are not nearly enough—at least not as currently practiced.

We couldn’t resist posting our own observations about weight loss and exercise. From the female perspective:

Back when I was a wee lass (in college), I recall weighing myself in the locker room after a tough workout for the crew team, and weighing in at 120 lbs. My usual weight was probably more like 125 lbs. (It sure would be easier to sprint up the stadium steps at 125 lbs than my current weight of 150 lbs!) I don’t know for sure whether there was any weight change as a result of crew training, but I remember eating enormous amounts during spring break when we worked out three times a day! Crew workouts can easily spend energy at the rate of 1000 kcal/hr (though few could keep up that pace for very long).

Then in my mid-twenties, I jogged a lot and ran several marathons. I didn’t train excessively—I probably logged 35+ miles per week, with occasional longer weeks when preparing for longer distance events. It helped me deal with stress and improved my confidence and self-image. Overall, jogging was a good thing for me, though I was never fast. (I almost qualified for the Boston marathon once, but got injured and had to slow down-- I could never be a world class athlete). I was thin then, but not skinny. I don’t recall even having a scale then, so I have no data on my actual weight (though I still have some clothes from that era, which currently do not fit). I remember, in particular, a friend asking if I was having any menstrual cycle disturbances from all this running, and I replied no. He felt my arm and said something like “of course not” in a derogatory voice, meaning I was way too fat for that. Did I say friend? I meant obnoxious jerk!

At any event, I was slim, healthy and strong (relatively), looked better than ever, and ate plenty of carbs (although I recall eating mayonnaise straight out of the jar once after a long run I was so starving!) I was also single, and that I think turns out to be the real kicker here. At least for me, I am less likely to eat well when eating alone. Conversely, I tend to overeat at times when eating with friends and family. I suspect this may be true for many others as well. So I can’t say for sure that my relative slenderness as a young runner and marathoner was only due to the exercise.

Twenty odd years later, running doesn’t do the same thing for me. I have a family—we cook great meals in our house, enjoy desserts, and generally relish living. Is it the inevitable middle-aged spread? Is it due to reductions in hormones related to the aging process? Not exercising enough? Is it due to excess calories in general? Or fat or carbs in particular?

I started using an ankle brace regularly on trail runs (see for example Monte Bello OSP or the Bay to Ridge Trail ) about 2 years ago to prevent the perennial ankle sprains I am susceptible to (it has worked well!). I was able to train more or less consistently for longer periods of time. My weight stabilized, but I couldn’t seem to lose any weight, even with ever increasing mileage. An hour or so of jogging or uphill walking most days was typical, with occasional 3–4 hour outings, frequently covering a few thousand feet in elevation change. You’d think the weight would just fall off, but it didn’t. Any interruption in training saw the weight pile on quickly too (whether due to breaks from work demands, bad weather, holidays and holiday eating, illness or injuries). I think there is a tendency after long or hard exercising to believe that you are entitled to a few extra calories, and slightly larger serving sizes of food become habitual, and there goes any weight loss! It’s trivial to eat a few hundred calories extra, and not so trivial to burn them off. (See, for example, the chart at myfit.ca.) Also, there is evidence that exercise increases insulin secretion and growth hormone production (but that’s another post…). Certainly I have found myself famished after longer training events, and not satisfied with just one meal.

So why did it seem to work when I was in my twenties? I’m not sure—there are many factors that could have contributed. More importantly, why is it working now that I’m restricting carbs in my diet? I’m not even sure the exercise has anything to do with it. We’ve seen some of the fastest decreases in weight when exercising the least. For example, after an injury (I dislocated my elbow in early May) and cutting back on distances and speed, I spent a whole month with my weight consistently below the trend line on my weight loss graph. Afterwards, we started doing more distance again and pushing the pace, and the weight actually increased for a few weeks. (See our earlier posting about weight loss curves.)

From the male perspective:
My experience is, I think, quite typical of active males. I've always been a fast eater with a relatively high metabolism. Fast eaters tend to overeat a bit, and I tended to be 5–10 lbs above my ideal weight as I was growing up. I then went through periods when I was extremely active and periods when I was relatively sedentary. As a competitive varsity athlete in college, the weight naturally came off. It also came off when I spent summers mostly outdoors backpacking a lot and when I worked more physically active jobs organizing trail runs and doing construction work. I also ate more at those times. As I've gotten older, my weight has gradually gone up roughly along the typical pound-per-year curve. There have tended to be spikes when my level of activity decreased suddenly (when I stopped doing the physically demanding sport or job, and I had to relearn how to eat less and feel satisfied). The weight always seemed to have a local (in time) set point that was not very dependent on short-term variations in the amount I ate.

A few years ago, I switched once more from a period of high-activity work to more sedentary work, and my weight started drifting upward alarmingly even with significant efforts at reducing calorie intake. Essentially, I was starting to exhibit the typical set of symptoms known as metabolic syndrome: weight gain, increased waist circumference, moderate elevation of blood glucose levels, moderately elevated triglycerides, high blood pressure. If I paid close attention to my weight and caloric consumption, I could temporarily get some of the weight off, but it tended to come right back as soon as I stopped paying attention or went through a holiday period. Adding back in a strenuous exercise program also helped temporarily, but always tended to drive up my calorie consumption. Basically, I was confirming the usual experience that diet and exercise only sort of/maybe work to keep weight under control, and only if you pay close attention and keep paying attention. I've now lost all of the recent excess weight gain (about 25 pounds), though I'm still 30 pounds over what I weighed as a college athlete. The secret has really been exactly what my pediatrician told me 40 years ago before we all went low-fat, low-cholesterol: cut back on the simple starches and sugars! I don't make any attempt to calorie-restrict, or count calories—I'm rarely unusually hungry. I've just cut way back on the amount of sugars, potatoes, and grains I eat. End of story.

If anything, our relatively generous exercise schedule seems to lead to an ability to tolerate a few more carbs in our diet, but I’m sure if we restricted even more, we’d lose faster. Having adapted to a low carb diet, our metabolisms are acting in a carb-sparing capacity, using fat preferentially so that the glycogen is there for emergencies. It’s unclear whether we are even glycogen-depleted anymore. Certainly our blood glucose levels are stable—the body readily manufactures glucose from protein, and we eat sufficient protein so that we’ve never really been all that ketogenic (we’ve checked).

The body contains something like 400 g glycogen, stored in muscles and the liver. This glycogen binds 2.6 g water per gram of glycogen, and hence the total weighs 1440 g in total in the body—3.2 lb). Low carb critics often incorrectly state that the weight lost on a low carb diet is only “water weight,” due to the loss of glycogen stores. Those 400 g of glycogen theoretically contain about 4 kcal/g of metabolic energy (assuming efficient conversion), so that’s 1600 kcal worth of carbs that could theoretically be eaten each day if you burned all the stored glycogen for energy during exercise.

Of course, that’s not how it actually works in aerobic or mixed aerobic/anaerobic exercise. Unless you are exercising beyond your anaerobic threshold for long periods of time, or your aerobic fitness is very poor, fat is the preferred energy source for exercise. Just keeping to a pace where my heart rate is elevated (130–160 beats per minute) means I must cross the anaerobic threshold at least some of the time, but even so, there’s no way that I deplete all my body glycogen during normal exercise. One exception might have been a time about two weeks into our low carb diet when we went on a particularly difficult route, climbing and descending about 2000 ft and covering about 11 miles (in a cold rainstorm!). By the end, I was cramping and weak (might have been due to the cold too), and my blood glucose was down to 76 mg/dl. Every other time, even if exhausted to the point of feeling ill, my blood glucose was never below 90 mg/dl. I was never in any danger of completely running out of glucose for fuel (or fat!). (See this nice discussion of fat vs. glycogen burning in distance training.)

So if you are eating 2000 kcal at 60% carbs as recommended by many medical professionals, that's 1200 kcal from carbs consumed every day. But it's very unlikely that you will use up and need to replenish that much glycogen every day from normal exercise and living activities. Unfortunately, the body naturally stores at least some of the excess as fat.

So, our conclusion to date is that exercising is a great thing to do, but is not necessary or necessarily even helpful for weight loss at all (though of course it is very helpful for general health, increasing insulin sensitivity, raising HDL levels, etc.) On the other hand, if you eat large amounts of carbs, you'd better burn it off somehow or the likely destination for a lot of the excess is your fat stores!

Fruit is Good for you, Right?

2008-07-26T13:39:00.000-07:00

We've all been taught that we should eat plenty of "fruits and vegetables." Fruits and vegetables are rarely separated out in nutritional guidelines. They are separated but paired in the USDA food pyramid which recommends eating about equal parts "fruits" and "vegetables." (A more detailed version of current USDA recommendations can be found at mypyramid.gov and health.gov.) Parents are typically happy if they can get their children to eat lots of fruit juice and fruit products (typically with added sugar) when they won't eat much in the way of vegetables.

Even among those who are supposedly being more discriminating about their food choices, fruits are almost always treated as something to eat in large, if not unlimited, quantity. For example, the Paleo Diet, which attempts to recommend a diet alleged to be similar to that of our hunter-gatherer ancestors, recommends consuming "all the fruit and non-starchy vegetables you can eat." (You are warned against eating too much dried fruit—most fresh fruits are about 80–90% water, so removing most of the water can dramatically increase the total quantity you can eat. Similarly, some people warn against drinking too much fruit juice which is another way you can consume a lot more fruit very quickly.)

Fruits are alleged to be good for you, because they contain a lot of essential vitamins and minerals as well as fiber and such newer necessities as "phytochemicals" and "antioxidants." So what's really in fruit? Even those of us who habitually read nutrition labels tend to be unfamiliar with the nutritional content of most fruits, since, as typically sold fresh, there aren't any nutritional labels. The following table gives some data for a lot of common (and a few less common) fruits.

Fruit	Protein	Fat	Carb	Fiber	Sugar	Fructose	Glucose	Sucrose	Other	All based on 100 gm serving
Apple	0 g	0 g	13 g	1 g	10 g	6 g	3.2 g	0.8 g	7% C
Apricot	1	0	11	2	9	0.9	2.4	5.9	39% A, 17% C, 7% Potassium
Banana	1	0	23	3	12	4.9	5.0	2.4	15% C, 18% B6, 10% Potassium, 13% Mn
Blackberry	1	0	10	5	5	2.4	2.3	0.1	35% C, 32% Mn
Blueberry	1	0	14	2	10	5.0	4.9	0.1	16% C, 24% K, 17% Mn
Breadfruit	1	0	27	5	11				48% C, 7% Thiamin, 6% Mg, 14% Potassium
Cherry (sour)	1	0	12	2	8	3.5	4.2	0.8	26% A, 17% C
Cherry (sweet)	1	0	16	2	13	5.4	6.6	0.2	12% C, 6% Potassium
Cranberry	0	0	12	5	4	0.6	3.3	0.1	22% C, 6% E, 6% K, 18% Mn
Date	2	0	75	7	66	32.0	33.7	0.5	8% Niacin, 12% B6, 8% Pantothenic Acid, 6% Ca, 14% Mg, 6% P, 20% Potassium, 18% Cu, 15% Mn
Fig	1	0	19	3	16				6% K, 6% B6, 7% Potassium, 6% Mn
Grapefruit (pink)	1	0	11	2	7	1.8	1.6	3.5	23% A, 52% C
Grape (red or green)	1	0	18	1	15	8.1	7.2	0.2	18% C, 18% K, 5% Potassium, 6% Cu
Guava	3	1	14	5	9				12% A, 381% C, 6% B6 12% Folate, 12% Potassium, 11% Cu, 8% Mn
Kiwi	1	1	15	3	9	4.4	4.1	0.2	155% C, 7% E, 50% K, 6% Folate, 9% Potassium, 6% Cu
Lemon	1	0	9	3	3				88% C
Lime	1	0	11	3	2				48% C
Mango	1	0	17	2	15				15% A, 46% C, 6% E, 7% B6
Melon (honeydew)	1	0	9	1	9	3.0	2.7	2.5	30% C, 7% Potassium
Nectarine	2	0	15	2	11	1.4	1.6	4.9	7% A, 9% C, 6% Niacin, 6% Potassium
Orange	1	0	12	2	9				75% C, 7 Thiamin
Papaya	1	0	10	2	6				22% A, 103% C, 10% Folate, 7% Potassium
Passion fruit	2	1	23	10	11				25% A, 50% C, 8% Riboflavin, 7% Niacin, 9% Fe, 7% Mg, 7% P, 10% Potassium
Peach	1	0	10	1	8	1.5	2.0	4.8	7% A, 11% C
Pear	0	0	15	3	10	6.2	2.8	0.8	7% C, 6% K
Pineapple (sweet)	1	0	13	1	10	2.2	1.7	6.5	94% C, 6% B6, 6% Cu, 41% Mn
Plum	1	0	11	1	10	3.1	5.1	1.6	7% A, 16%, C
Pomegranate	1	0	17	1	17				10% C, 6% K, 6% Pantothenic Acid, 7% Potassium
Raspberry	1	1	12	6	4	2.4	1.9	0.2	44% C, 10% K, 34% Mn
Rhubarb	1	0	5	2	1				13% C, 37% K, 9% Ca, 8% Potassium, 10% Mn
Strawberry	1	0	8	2	5	2.4	2.0	0.5	98% C, 6% Folate, 19% Mn
Tamarind	3	1	63	5	57				6% C, 29% Thiamine, 10% Niacin, 7% Ca, 16% Fe, 23% Mg, 11% P, 18% Potassium
Watermelon	1	0	8	0	6	3.4	1.6	0.1	11% A, 13% C

(All data from nutritiondata.com. Vitamin and mineral content are given as % daily value. 'K' is Vitamin K; potassium is spelled out.)

As you can see, fruits are mostly sugar and water. There's typically about 1% protein, no fat, a modest amount of fiber, and a very small amount of more complex nutritive carbohydrate. Some fruits are admittedly good sources of particular vitamins and minerals, but you get a pretty generous "spoonful of sugar" with your daily dose of vitamins and minerals if you get them mostly from fruit. If you're after the trace nutrients, you'd be better off with vegetable sources anyway. Compare the following (the first three of which are arguably "fruits" in the botanical sense, although we usually call them "vegetables," because of the ways we tend to serve them).

"Vegetable"	Protein	Fat	Carb	Fiber	Sugar	Fructose	Glucose	Sucrose	Other
Tomato	1	0	4	1	3	1.4	1.2	0.0	17% A, 21% C, 10% K, 7% Potassium, 6% Mn
Cucumber	1	0	4	0	2	0.9	0.8	0.0	21% K
Green Bean	2	0	7	3	1				14% A, 27% C, 18% K, 6% Thiamine, 6% Riboflavin, 9% Folate, 6% Fe, 6% Mg, 6% Potassium, 11% Mn
Broccoli	3	0	6	2	2	0.7	0.5	0.1	12% A, 149% C, 127% K, 7% Riboflavin, 9% B6, 16% Folate 6% Pantothenic Acid, 7% P, 9% Potassium, 10% Mn

There doesn't seem to be any good reason to eat fruits for their higher vitamin content; the vegetables have more vitamins anyway! Vegetables provide generous amounts of fiber as well.

So then maybe fruit sugars are somehow better for you? Certainly many "natural foods" advocates seem to believe that "natural" and "unrefined" sweeteners are somehow OK when table sugar is not. But the sugar in most fruits is nutritionally almost the same as that of table sugar. Table sugar is sucrose which is a disaccharide made up of equal parts fructose and glucose. Most fruits also have approximately equal amounts of fructose and glucose either separately or combined as sucrose. The body breaks apart the sucrose right away. Fructose and glucose are metabolized somewhat differently. While fructose has an apparently lower glycemic response, it appears to be more harmful overall resulting in elevated triglyceride levels and fat storage much more than does glucose. So focusing on apples and pears with their higher fructose content is probably even worse than going for the fruits with more balanced sugar content. A more detailed discussion of the metabolism of fructose and glucose can be found in Basciano et al., "Fructose, Insulin Resistance, and Metabolic Dyslipidemia," Nutr. & Metab., 2005, 2:5.

So my conclusion from all this is that fruits are not health food! They're by no means terrible, especially when consumed in moderation as whole fruit, but as macronutrients, they are primarily bags of flavored sugar water. Particularly if you are trying to cut back on total carbohydrate consumption and on sugar consumption in particular, you should seriously consider limiting your fruit intake and increasing your vegetable intake instead, or at least focusing on lower-sugar fruits such as raspberries, blackberries, and cranberries. For us, fruit is relegated to the role of dessert, to be consumed once or twice a day in ~½-cup portions, to alleviate carb cravings. This way, the sugar loading from fruit is kept to a minimum of 20–25 g.

More on the Thermodynamics of Body Weight

2008-07-20T08:43:00.000-07:00

The previous post was intentionally general with no specific finger-pointing to misuse or good use of thermodynamic arguments. The misuse is so widespread, that I still prefer not to provide specific references. However, it is worth pointing to a few recent papers that have taken the issue more seriously.

First, I should note that to a high percentage of even trained scientists and doctors, "thermodynamics" means "equilibrium thermodynamics." This is all that is taught in a typical introductory course. Unfortunately, the human body can rarely be modeled accurately as being in any sort of equilibrium. At best, it may be reasonable (at least for some time scales) to model it as being in something approaching a "steady-state." As such, a complete analysis must include a study of "dynamic," "kinetic," or "nonequilibrium" effects, i.e., you must look at all inputs and outputs, and potentially the rate of change of inputs, outputs, and the state of what's inside.

One recent paper which tackles the issue head-on is by Feinman and Fine: "Nonequilibrium thermodynamics and energy efficiency in weight loss diets," Theoretical Biology and Medical Modelling 2007, 4:27. The authors specifically focus on the greater weight loss observed in low-carbohydrate diets with an emphasis on the specific "kinetics" of fat storage and dissipation arguing that simple equilibrium models fail, because real bodies, and especially real bodies that are in transition (gaining or losing weight) can be far from equilibrium requiring the consideration of dynamic effects. While they find that no experiment exists that measures all relevant variables, they are able to find evidence that dietary carbohydrate controls fatty acid storage and release via its effect on hormone levels (particularly insulin) and that this "nonequilibrium" effect can explain the greater weight loss of low-carb diets.

Another paper by Schulz and Schoeller, "A compilation of total daily energy expenditures and body weights in healthy adults," Am J Clin Nutr 1994, 60:676, reviews 22 studies which use an important (if somewhat expensive) technique for measurement of what they call "total expenditure energy" (how much energy is used over, say, a day or a week for all physical activity. The technique uses "doubly labeled water" (both the hydrogen and oxygen atoms are non-standard isotopes so that the differential kinetics of hydrogen and oxygen can be measured). The authors present data for various populations from elite athletes to normal and overweight individuals. Most notably, the total daily energy expenditure is found to vary by a factor of more than 3. To a limited extent, they were able to separate out the contributions of basal metabolic rate and physical activity, fat-free body mass and excess fat. While not specifically focused on thermodynamic equilibrium, it does add further evidence against any simple "calorie is a calorie" model of diet and weight.

And not being completely unable to resist highlighting one paper that is unwilling to draw the right conclusions from its own data, consider Brehm et al, "The role of Energy Expenditure in the Differential Weight Loss in Obese Women on Low-Fat and Low-Carbohydrate Diets," J Clin Endocr & Metab, 2005, 90:1475. Their paper reports the results of weight loss comparisons for obese women following the two diets for six months. The Low-carb group lost 50% more weight despite not being specifically calorie-restricted. (Food diaries indicated that the caloric intake was nevertheless similar between the two groups.) Not being able to measure any significant difference in resting energy expenditure or physical activity, the authors fell back on the old standby: the low-fat dieters must have cheated and underreported actual food consumption! The possibility that the results could be real apparently wasn't acceptable.

"Thermodynamics" of Weight Gain and Loss

2008-07-19T11:05:00.000-07:00

A common belief among the proponents of calorie restriction and exercise as a means of weight loss is that "thermodynamics" (or more particularly, conservation of energy) says it must be so. The basic premise is that:

Energy-in - Energy-out = Energy-stored-as-fat

Therefore, if you want to lose weight (make Energy-stored-as-fat negative), then Energy-out must exceed Energy-in. This is then interpreted to mean that you must either eat less or exercise more to change this balance. People then go into elaborate calculations as to how many Calories you burn with various sorts of exercise and how many Calories are in different diets.

A few authors have recognized that this same equation can be interpreted a little differently. They argue that no one can actually regulate their energy intake precisely enough to have a constant weight over any length of time. Therefore Energy-stored-as-fat must be regulated by the endocrine system and be more or less fixed. Then, the thing that has to change when you eat more or less is the Energy-out; i.e., the body adjusts its energy expenditure (without a specific conscious exercise program) to burn available excess energy, and conversely, if you get an unusually large amount of exercise (run a marathon, for example), then you will naturally eat more to replace the energy used.

I believe the real picture is a good deal more complicated than any of these simple descriptions. As a physicist and thermodynamicist, I look at a "control volume" (a human body in this case), and consider all of the flows of mass and energy in and out. Any net differences must be stored internally. Inputs include the food and drink consumed and the air breathed in (most of the time, direct energy inputs [mechanical or thermal] can probably be ignored as small). Outputs include waste excreted, air breathed out (with a different composition!) and any mechanical work performed. It is important also to recognize the energy associated with differences in the internal potential energy associated with the any chemical changes that may occur between matter taken in and matter excreted. These represent a form of possible difference between energy-in and energy-out.

So, consider someone who is eating, say, an "extra" 1000 Calories a day. He could store it as a quarter pound of fat and gain a couple of pounds per week. He could get restless and move around a lot more, expending at least some of the excess as mechanical energy. His peripheral capillaries could dilate so that he loses more energy thermally through his skin. He could simply excrete some of it as undigested. I have always suspected, for example, that there is an upper limit to the rate at which food can be processed in the body, and if you exceed that limit by binge-eating or feasting on a particular day, then most of the excess is simply excreted rather than stored.

People often report that even large increases in the amount of exercise they get does not result in weight loss. Some portion of this may be a consequence of muscle development ("good" weight gain). But to a large extent, it is very hard not to just eat more in response to the body's repair and recovery processes after exercise.

Similarly, if you try to lose weight by starving yourself, your body tends to try to conserve energy to compensate (and you may be chronically suffering as your body tells you to eat more!). People who literally go on starvation diets (either intentionally or as a result of disaster) often report a permanent reduction in their "metabolism" to the point where they eat much less after the period of starvation (or quickly gain back any weight lost).

All of this means, that if you really want to change body weight (either up or down), you really need to be tinkering with the endocrine system to stimulate release or storage of fat. That's rather complicated, and I don't understand it very well myself. It's a bigger topic than I want to tackle today, anyway. Moderate amounts of exercise are probably beneficial. But probably the simplest thing that most people can do is to control carbohydrate consumption, particularly simple sugars and starches (including those found in "whole" grains and most fruits). These tend to set off a chain of hormonal events including a large spike in insulin production, triglyceride production and ultimately fat storage. If you keep your insulin and triglyceride levels low, you tend to take fat out of storage instead.

Anyway, the purpose of this post is not to promote any particular approach to weight management, but merely to argue that if you're going to invoke "thermodynamics" in discussing it, make sure you are properly accounting for all the energy inputs, outputs, and transformations that are occurring, and be very careful that you are drawing the right conclusions.

Among Diabetics, only the Mediterranean diet decreased plasma glucose?

2008-07-17T13:08:00.000-07:00

The recent New England Journal of Medicine article comparing long term results with low fat, Mediterranean and low carb diets published yesterday, and made quite a splash in the media. The article is free to the public (Thank you NEJM!) As usual, either the authors or the media, in their fervor to get a "message" out to the public, screwed it up again. The message everyone seems to be taking from this study is that Mediterranean diets are better for diabetics than low fat or low carb diets, the other two diets tested, when that is not what the article says at all!

It doesn't help that the authors state in the abstract that

"Among the 36 subjects with diabetes, changes in fasting plasma glucose and insulin levels were more favorable among those assigned to the Mediterranean diet than among those assigned to the low-fat diet..."

Note that they did NOT say "more favorable than among those assigned to the low-carb diet." Was this a concession to mainstream medicine? Did they feel that they would take too much flak or not get funding for their next study if they went too far in supporting low-carb "fad" diets?

It is beyond me why they did not state in the abstract that those on low carb diets had the lowest glycated hemoglobin levels, since we know that glycated hemoglobin levels are a much better measure of average blood glucose levels and blood glucose control than a few isolated fasting glucose values. This seems to me to be one of the strongest points from a public health perspective, and it needs to be said louder.

Think I am hallucinating? Reading into the data what I want to see? Right there on page 235 (and continuing on page 238) the article says:

"Among the participants with diabetes, the proportion of glycated hemoglobin at 24 months decreased by 0.4±1.3% in the low-fat group, 0.5±1.1% in the Mediterranean-diet group, and 0.9±0.8% in the low-carbohydrate group. The changes were significant (P<0.05) only in the low-carbohydrate group (P = 0.45 for the comparison among groups). I suspect that Mary Vernon and Eric Westman will have similar observations (see their their earlier thoughts on the ACCORD trial and this one (with a hoard of other authors too). (Thank you for pushing the issues with mainstream medicine!)

The authors of the NEJM article calculated the "homeostasis model assessment of insulin resistance" (HOMA-IR) according to the following equation (see Diabetes Care 1997;20: 1087-92) as follows : insulin (U/ml) × fasting glucose (mmol/liter) ÷ 22.5. Their observations about HOMA-IR are interesting, and serve as the basis for their conclusion that the Mediterranean diet worked better for diabetics than the low fat diet. What they again fail to state (though it is also shown in Fig. 4F) is that the HOMA-IR improved most on the low carb diet in non-diabetics. This point is certainly relevant from a public health perspective for diabetes prevention, is it not?

Another curiosity is that the low carb dieters were counseled to choose vegetable sources of fat and protein (ostensibly to reduce trans-fats—Since when is animal fat a significant source of trans-fats?)? I'd like to know what if any effect this urging had on the dieters, and what effect it had on their lipid levels and other parameters measured (if those measures are even relevant…).

Ranting aside, this was a nicely done study, with better control than in many, and for a longer period of time. It should end the speculation and criticism that low carb diets show short term benefit only. It's clear that the weight losses were much better at 5–6 months for both low carb and low fat diets, and that relaxation of dietary stringency most likely resulted in weight re-gains. Certainly, the increase in triglycerides in the low carb group demonstrates an increase in carb consumption (despite the higher fat intake during the more stringent phase) and is likely responsible for the weight re-gains. The Mediterranean diet seemed easier to maintain, judging by the better weight maintenance, but it's not clear why this should be.

The authors were not cagey at least about the more favorable effects on lipids with the low-carb diet, and even with less compliance and some weight re-gain in later phases of the diet, these results were maintained.

I am left with my usual confusion over what constitutes a "Mediterranean diet" though—as described, it seems that the only significant difference between the "low-fat" diet and the "Mediterranean diet" was the substitution of olive oil for some of the meat fat (and a slight increase in the total amount of fat). Does substitution of 5–7 nuts for a few pretzels turn a low fat diet into a Mediterranean diet? Certainly most "low fat" dieters believe they are eating "healthy" diets high in grains and vegetables, but low in "evil" fat. This study represents another nail in the coffin of the low fat dogma, and in that respect as well, I am pleased.