ENERGY-EXPENDITURE VARIATIONS IN SOLDIERS PERFORMING MILITARY ACTIVITIES UNDER COLD AND HOT CLIMATE CONDITIONS

This study assessed the energetic status of soldiers exposed to intens e physical activities in cold and warm weather. Thirty subjects partic ipated in a two-phase study: group A (n = 18) in the winter phase and group B (n = 12) in the summer phase. Energy expenditure (EE) was meas ured by the doubly labeled mater technique; after a single, oral dosin g of (H2O)-H-2-O-18, daily urine samples were collected for 12 success ive days. Energy intake (EI) was assessed from detailed food records a nalyzed by computerized food charts. Energy balance was calculated as the difference between EI and EE for each subject Mean (+/-SE) daily E E was 4,281 +/- 170 and 3,937 +/- 159 kcal/day for the winter and summ er groups, respectively. Dairy EI was 2,792 +/- 124 kcal/day in group A and almost identical in group B. A negative energy balance of 1,422 +/- 163 kcal/day and 924 +/- 232 kcal/day (not significant) was calcul ated for groups A and B, respectively. Energy expenditure is primarily determined by the level of activity rather than by climate conditions ; EI is insufficient to offset the high energy requirements under thes e conditions.