Evolutionary Fitness and the Endurance Athlete's Dilemma

Right now, many of you are entering your peak training weeks in preparation for your August and September events. Bottom line, you need more carbohydrates in your diet to fuel your increased physical output and – hopefully – minimize any negative physical effects of endurance training.

In two prior posts, I highlighted ways to strengthen and fortify your body from the effects of endurance training:

1. Power Law Strength Training
2. Paleo Eating

I had a few questions come up with regards to the special dietary needs of endurance athletes. Once again, I’m going to defer to Mark Sisson’s recommendations:

When you go for endurance training, you face (among other physical strains) the necessity of increased carb intake and all its negative results (e.g. inflammation, AGEs (avanced glycation end products), impaired immune function, etc.). Myself, I had a half-gallon of ice cream, loaf of bread and cereal habit going to refuel every day for years. At the time, I didn’t see an obvious impact on my performance, but I later realized I was causing long term damage. A better, more Primal approach to a training diet includes meals full of veggies (universal recommendation, yes) as well as the judicious use of fruits and tubers for added “healthier than grains” carb sources. (Of course, your diet should include a hefty supply of protein and natural fats.)

On a Primal Blueprint (PB)-style low carb diet, with PB-style low training time, the body makes 200 grams of glycogen each day from fats and protein (and then we figure another 100 or so from your veggies and fruits). That gives you enough glycogen to fuel your brain, cruise through an average day and to be able to do a short hard workout – and then do it again the next day. However, when you train long every day (over an hour), your carb needs will increase. The key is discovering EXACTLY how many additional carb grams you need each day to refuel muscles, but also to keep insulin and fat storage to a minimum. Too few and you won’t recover from day-to-day. Too many and you’ll set yourself up for inflammation and unnecessary weight-gain.

Right after a long training session or race, you’re in a critical period for glycogen refueling. That first hour offers the most efficient opportunity for glycogen storage, and it’s fine to refuel initially with simpler (faster uptake) sugars. Take it slow and go for drinks first until you think you can safely move onto solid food. When you’re ready, try some fruits or yogurt with honey to get both carbs and protein in that initial window. As you move past that first hour, tubers and more complex carb sources are good to include. As I tell everyone, try to avoid grain-products as much as possible when increasing carbs. Depending on the length and intensity of your workouts (and races) you’ll need anywhere between 60-100 extra grams of carbs (beyond what we discuss above on a low carb plan) each day per hour of intense endurance work. It’s well worth the trial and error efforts to gauge your personal need and dial it in precisely.

I’d also suggest redirecting your training toward long and slow stuff with occasional fast and intense interspersed. Doing so will allow you to keep building endurance capacity while better “training” your body in fat burning efficiency.

Races or any intensive training session lasting over 90 minutes often call for added carb refueling on the fly, too. Over the years coaching athletes, I’ve found that drinking 10-20 grams of sugars every 15 minutes after the first 60-90 minutes helps keep glucose in the bloodstream and thereby spares muscle glycogen. Any more than that and you run the risk of stomach upset. Once again, sports drinks are probably the most efficient source for carb energy, electrolytes and hydration. Though a piece of fruit might work for borderline training days, eating solid foods during a race generally backfires. Additionally, sport drinks have some advantages over straight juices. There’s a reason these drinks have been around for a while. I’d do some comparison shopping and personal trials to find one you prefer.

Finally, wise (i.e. comprehensive and potent) supplementation is an absolute must. In comparison with the average Joe or Jane, endurance training inevitably depletes the body. You’re doing more than the body was naturally designed to do. Moreover, the amount of oxidation (and free-radical damage) taking place during that time is tens or hundreds of times greater than what you experience at resting metabolic rates. Consequently, your nutrition needs will be higher – especially the need for extra antioxidants. It’s critical you refuel all nutrient stores and take in higher levels of anti-oxidants that can help repair the damage training (in addition to everyday living) causes.