Thursday, July 2, 2009

GamJams Reviews: On-bike nutrition (off-beat advice)

Paleo Basics

I know this is about what to eat on the bike, but that happens within the context of a complete nutritional plan. My overarching strategy is provided by the Paleo diet. I read Loren Cordain's book not long after it came out, and with a few exceptions, found the logic compelling.

The theme is that our bodies evolved for a hunter-gatherer, pre-agricultural diet, a diet we consumed for nearly half a million years before the invention of agriculture a mere 10,000 years ago. Although agricultural technology allowed the human population to explode, each individual person raised on farmed cereals (rather than gathered plants and hunted meats) fared worse. Post-agricultural skulls are smaller and skeletons show evidence of bone disease, tooth decay, chronic illness, shorter lifespans, and on and on.

The Paleo diet attempts to mimic hunter-gatherer intake as closely as possible in the modern world. This is what you eat: meats, eggs, vegetables, fruits, nuts, and occasionally, honey. This is what you do not eat: anything else. In particular, no processed foods, no sugars, no bread, no pasta, no rice, no legumes even. You get all of your carbs through fruits and veggies. Meats should be grassfed beef, organic, free-range chicken and pork, and wild fish. (Standardly-raised animals consume a diet of corn, and are therefore low in omega 3 and high in omega 6: very unpaleo.)

When you get all your carbs from fruits and veggies, you realize how meager the nutritional content of cereals really is. Compared to the Paleo stuff, you get hardly any vitamins and minerals out of one calorie of bread.

Wars rage as fiercely on the subject of diet as on anything in popular science, and everything you were told as a kid (or heck, last month) is now up for grabs. But at the macro level, I see a convergence of theories and studies onto the basic tenets of Paleo. Nobody is out there promoting simple sugars and processed foods. Everyone realizes that our super-high ratio of omega 6-to-omega 3 fats is behind a lot of our inflammation-based health conditions, and maybe depression. Nobody thinks fresh fruits and vegetables are going to hurt you. The remaining controversies are over:

1. the optimum percentage of fat intake, where the trend is definitely towards higher values;
2. the status of saturated fats, where the consensus that they're bad is falling apart;
3. meats, which are looking better and better;
4. grains, particularly wheat, which even in unprocessed form are not looking so great.

(Gary Taubes' book on the history of these controversies is a work of journalistic genius, a bizarre tour through the underbelly of scientific practice. A lecture overview is here.)

It's hard to stick to a Paleo diet and maintain any kind of social life. It's also really pricey. But I've done it off-and-on. Mostly, it's been off, but when it's been on, I've had fantastic results in terms of mood, energy levels, and body composition. So much so that in these periods on the diet I become something of a zealot.

Paleo for Athletes

Ahhhh... but what about cycling? Don't we need simple sugars, quick-burning calories, to fuel our efforts? Yes. Yes we do. Base training can reduce your reliance on carbs and switch you over to burning a high percentage of fat, but for racing and hard intervals, you need lots of fast-burning carbs. There's no way around it. And you won't be able to digest spinach, tomatoes, and zucchini fast enough to meet your requirements.

Our paleolithic ancestors were incredibly fit, ultraendurance athletes who persistence hunted, but they did not train and race repeatedly at super high intensities, and therefore they could get along burning mostly fat, along with a modest amount of carbs.

What to do? Enter Joel Friel, who paired with Cordain to modify the Paleo diet for modern endurance athletes. Their book suggests stacking simple carbs around workouts, pre-, during, and post-exercise, and otherwise sticking to a strict paleo intake. So long as you are burning all of your simple carbs in the moment, you won't suffer from any of their metabolic ill effects (i.e., insulin spikes).

So, when on the bike, I often eat what everyone is recommending on GamJams: Shot Blocks, gels, candy bars and such. It's just that for me, this modern agricultural stuff is a massive departure from the rest of my diet.

On-Bike, Off-Beat
Here are two on-the-bike recommendations, though, that I have yet to see in these reviews.

First of all, I do glycogen depletion rides sometimes in the mornings. These workouts are the brainchild of Dr. Michael Ross, who points out that really long rides have all kinds of nasty side effects like lowering good hormones and weakening muscle fibers, but they're great for forcing your body to learn to metabolize fat. Ross's idea is that you should ride first thing in the morning, before eating, at fairly high intensity for one hour. The glycogen in your liver is already low at this point, and the ride steals what's left of the glycogen in your legs. An hour at intensity brings you right to the point of bonking, but not over it. Up close to the bonk, your muscles are forced to adapt to the low glycogen environment by switching over to fats for fuel. Yet, at the same time, you do not work out long enough to thin the fibers or lower the growth hormone and testosterone levels.

On these rides, it's important that your body doesn't start consuming itself, that is, breaking down your own muscles to meet the energy demands. So Ross recommends adding some branch chain amino acids (BCAAs) to your water. Doing so has been shown to prevent muscle loss in glycogen depletion workouts. I bought some BCAA powder and used it once or twice, but when I looked at the ingredient list, I decided to substitute beef jerky, which I made myself from grassfed beef with a recipe from Alton Brown. I found the jerky is great on just
about any ride. It packs easily into a jersey, doesn't melt, and a few pieces will supplement your sugary drink or gel with perfect, complete protein, plus vitamins and minerals.

One other thing I haven't seen mentioned: a cold V8 is unbeatable on a hot ride. It's salty and loaded with vitamins, lycopene (which protects your skin against sun damage), and other micronutrients. My gas-station purchase is usually Gatorade, V8, and water. Maybe a fruit and nut mix.

You can't be strictly Paleo on the bike but you can do better than eating only processed, sugary foods.

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