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In the 1998 Raid Gauloises in Ecuador, our team made a major mistake. It was our only substantial
error, but it was potentially catastrophic. We had formulated a great food plan for the final leg,
but neglected to communicate this to our support crew. We left the last transition area with
enough food for only three hours, instead of three days. Apart from trading $200 in expensive
headlamps and watches for a bowl of chicken gruel and unripe papaya, we lost an average of 22
pounds each and a great deal of speed.
Better communication aside, you can mitigate the effects of poor nutrition using a few basic
tenets. First, an optimal diet supplies the nutrients needed for fuel and tissue maintenance
without exceeding levels that cause health problems. Although dietary preferences may necessitate
special adjustments, it’s best to follow sound nutritional guidelines.
Equations for endurance
Distance athletes must consume adequate useful calories to sustain prolonged exertion. I
stress the word useful because the popular press is full of misinformation that leads athletes to
believe they should consume more fat. Nothing is further from the truth. Despite numerous
testimonials and nonscientific studies, endurance athletes must obtain the bulk of their calories
from carbohydrates. As a small aside and counter testimonial to the current fad, the renowned
ultradistance runners, the Tarahumara Indians of Mexico, consume a diet that is 75% carbohydrates,
12% fat (2% saturated), and 13% protein and other sources. In contrast, a study of runners in the
United States revealed their diets to be 40% carbohydrates, 41% fat (12% saturated) and 19%
protein—better than their sedentary counterparts, but still outside the Recommended Dietary
Allowances.
For endurance athletes undergoing successive days of hard training, muscle glycogen stores are
rapidly depleted. Muscle glycogen (synthesized from ingested carbohydrate) isn’t the only fuel
source, but it is the primary source, and depletion leads to poor performance. A study of athletes
running 10 miles over three successive days revealed a 50% depletion in muscle glycogen by the end
of the study. This, despite the fact that all subjects were on a 40%—60% carbohydrate diet, which indicates that during exercise glycogen resupply is exceeded by the body’s utilization. The bottom line: Endurance athletes in heavy training must eat large amounts of carbohydrates to maintain adequate glycogen stores.
But how much is enough? This depends on the amount and intensity of training, but for adventure
racers and other distance athletes, recent research suggests 70% of calories, or 612g in a 3,500
calorie diet, should come from carbohydrates. Studies of male athletes during competition indicate
the following estimates of caloric expenditure:
Eco-Challenge: 80,000
Leadville Trail 100: 12,000
Ironman triathlon: 9,000
Bicycle road race: 6,000
Marathon: 5,000
Day on the couch: 1,500
It’s up to you do determine your caloric needs, but if you follow the 70% rule, you should remain tanked up to reach your full potential. You can also increase caloric expenditure on the couch by watching Eco-Challenge on TV. So get that remote control clicking—the nervous energy and adrenaline increases your basal metabolic rate, which burns calories even at
rest.
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