J278_Feature_NutritionPrtIII_tj_rr_ce_km.qxd
4/11/07
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Exercise lasting longer than 90 minutes depletes muscle glycogen and blood-glucose levels, while races lasting between four and 17 hours are extremely depleting. Carbohydrates are the foundation of any endurance athlete’s nutritional plan, and the first step is to calculate the number of carbohydrates/calories per hour that you require. It is not possible to replace all of the calories you burn during a race or workout—and attempting to do so may lead to a gastrointestinal meltdown on the run. Instead, the key is to replace just as much as is needed to sustain you through the duration of your training or race without causing GI troubles. The American College of Sports Medicine recommendation is to consume 30-60 grams of carbohydrate per hour during prolonged exercise. For a more precise calculation, grab your calculator. Women should try to consume one gram of carbohydrate for each kilogram (2.2 pounds) of body weight per hour, while men should take in 1.1 grams of carbohydrate per kilogram of body weight. If you want to convert this into units of energy, a carbohydrate has four calories. These numbers are a starting point, of course, and you may need to increase or decrease these values based on your metabolism, workout intensity and the conditions of the course. According to the results of testing I had in January, I need to consume 67 grams (that’s 268 calories) of carbohydrate an hour on the bike, far more than the 52 grams (208 calories) of carbohydrate predicted by the 1:1 ratio, but this is offset by needing only 40 grams (160 calories) of carbohydrate per hour on the run. Gordo Byrn, Ultraman Hawaii champion and co-author of Going Long, races at the extreme end, ingesting 125150 grams (500-600 calories) of carbohydrates an hour on the bike. He recommends replacing 50 percent of the calories expended on the bike. Since eating while riding is much easier (both logistically and physiologically) than eating on the run, be sure to fuel well on the bike. In fact, in one study of Ironman athletes, the ingestion rate was three times higher on the bike than it was during the run (Kimber et al., 2002).
Avoid a nutritional meltdown on race day By Joanna Zeiger
Inevitably, whenever I give a talk to a triathlon group somebody asks what my race-day nutrition involves. This is a perplexing question since race-day nutrition is extremely individualized, so I often joke that I eat spam sandwiches. Although the needs of one person rarely mimic the requirements of another, there are certain parameters that are nearly universal. So, when viewed in conjunction with the discussion about dehydration last month, your fueling strategy should no longer be scary and mysterious.
1 4 6 JUNE 2007
T R I AT H L E T E M A G . C O M
John Segesta/wahoomedia.com
COUNTING CALORIES