Mauna Kea III: Metabolic Effects of Dietary Carbohydrate Supplementation During Exercise at 4100 M Altitude.
Final rept. Jul 1985-Apr 1987
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA
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Twenty-nine male soldiers were divided into 3 groups to study the effects of exercise and carbohydrate supplementation on physical performance and metabolism at high altitude. All groups were provided a standard military field ration Meal, Ready-to-Eat containing 45 carbohydrate CHO was consumed ad libitum during 4 consecutive days of residence at an altitude of 4100 M. Two groups EX and EX CHO exercised while at high altitude by running and walking at about 75 maximum heart rate 2hday. The third group SED remained sedentary while at high altitude. One exercise group One exercise group EX CHO was permitted to consume carbohydrate sweetened beverages ad libitum as a supplement 250-350 g CHOday to the diet. The other two groups consumed similar beverages containing a non-caloric sweetener also on an ad libitum basis. Baseline measurements of food consumption, aerobic capacity, and blood and urine metabolites were recorded for all groups during 2 days of sedentary activity at sea level prior to rapid ascent to altitude 4100 M. Mean daily caloric intakes during the 4 days of exercise at altitude were 1513 kcal SED, 1787 kcal EX, and 2325 kcal EX CHO. The EC CHO group consumed an average of 404 g CHO day compared to 187 and 159 g CHOday for the EX and SED groups respectively. The EX CHO groups displayed a higher exercising respiratory exchanged ratio 0.81 or - 0.01 vs 0.77 or - 0.01, lower blood and urine beta hydroxybutyric acid and averaged 12.5 greater voluntary miles run over the course of the 4 day study. The study results confirm and extend previous studies suggesting that carbohydrate supplementation is beneficial during strenuous exercise at high altitude.
- Anatomy and Physiology
- Stress Physiology