Mountaineering sojourn: effects on body composition of prolonged exposure to high altitude in a cold environment

摘要

This study characterizes the basal body composition status of mountain climbers and examines changes in composition during a climbing expedition to high altitude. Subjects had selected physical and anthropometric (circumferences, skinfolds) measures taken immediately before (n=93) and after (n=29) an expedition to climb Mt McKinley, Denali National Park, Alaska. The anthropometric results were used to calculate the estimated percent body fat, lean body weight, and fat weight of the subjects. Climbing was attempted in elevation segments of 300 m per day to the summit (6193 m), and the length of the expeditions was 24.2 ± 0.8 days (mean ± SE). All before-and after-expedition measures were statistically analyzed with a two-tailed t-test for dependent samples. The basal status results showed the climbers to be better than average in compositional status for their age group. Statistical analysis of the before- and after-expedition measures indicated that there were significant reductions in all of the anthropometric measures. Additionally, body weight (74.5 ± 1.7 kg vs 71.6 ± 1.5 kg), percent fat (15.6 ± 0.7% vs 13.8 ± 0.7%), lean body weight (62.8 ± 1.3 kg vs 61.7 ± 1.2 kg), and fat weight (11.7 ± 0.7 kg vs 10.0 ± 0.6 kg) were all significantly (p < 0.01) reduced following the expedition. These data indicate mountain climbing to high altitudes significantly impacts overall body composition, reducing both fat and lean mass. However, these reductions appear more so in the adipose reserves than in the lean tissues of the body.