D-14M Free Communication/Poster Energy Expenditure
US Marine Corps (USMC) recruits, many who have previously been sedentary and/or overweight, must complete 12 weeks of recruit training, widely considered as physically demanding. However, energy expenditure rates during this training have not been documented, nor have the effects of gender and weight status on energy expenditure been quantified.
To compare total energy expenditure (TEE) of normal and overweight female recruits with normal weight male recruits during USMC recruit training at the Parris Island Recruit Depot, SC.
TEE was measured using doubly labeled water (< 2H2 18O) during a 14-day period in 30 recruits: 10 normal weight males (mean±SD, 18.8±0.9 y, 24.2±2.9 kg/m2, 12.6±7.8 % fat mass); 10 normal weight females (19.2±1.5 y, 20.1±1.3 kg/m2, 19.6±4.2 % fat mass); and 10 overweight females (20.3±2.8 y, 22.8±1.1 kg/m2, 26.3±2.9 % fat mass). Body composition was measured by DEXA. Basal metabolic rate (BMR) was calculated as 370 + (21.6 * FFM) where FFM is fat free mass measured by DEXA (Cunningham J, Am J Clin Nutr 1991; 54:963–969). Physical activity level (PAL) was calculated as TEE/BMR.
Weight changes during the 14-day measurement period (range 0.55–0.64 kg) were not significant (P = NS). TEE was higher in male (4048.3±946.0 kcal/d) than female recruits regardless of weight status (2360.1±306.4 kcal/d and 2396.4±447.6 kcal/d for normal and previously overweight recruits, respectively, F = 23.5, P = 0.0005). Similar differences were observed for TEE corrected for FFM, BMR, and PAL.
The data suggests that USMC recruits expend high levels of TEE, with higher TEE for male than female recruits, and that TEE for female recruits was not affected by weight status. Previously sedentary and/or overweight USMC inductees should be directed to attain a moderate to high level of fitness before reporting to recruit training to enhance their ability to maintain high levels of activity after entering recruit training.