Impact of a Special Operations Forces Basic Training on Body Composition and Energy Expenditure

Abstract

ABSTRACT Introduction The Belgian Special Operations Regiment undergoes an 8-week basic training course (SOF Basic Course) following the Military Initiation Phase. The aims of the present study were to estimate energy expenditure and changes in body composition during SOF Basic Course. Materials and Methods A multi frequency body composition analyser assessed baseline and endpoint body composition. For the purpose of estimating energy expenditure, 41 participants were fitted with triaxial accelerometers. T-tests were performed on paired and unpaired samples in order to estimate statistical significance. Effect size was estimated with Cohen’s d. Results SOF Basic Course was completed by 88 out of 126 participants. The participants’ mean (SD) age was 25.0 (4.1) years, weight was 77.6 (8.6) kg, and body fat percentage was 15.3% (3.3). Body weight of completers decreased from 78.3 (8.8) kg to 76.4 (8.0) kg (P = 0.01). Also, body fat decreased by 3.1 (1.8) kg (P = 0.01), and muscle mass increased by 1.2 (1.7) kg (P = 0.01). There was a decrease in body fat percentage from 15.3% (3.3) to 11.6% (3.4) (P = 0.01), with a Cohen’s effect size of 1.86. The loss of 3.1 kg of body fat corresponds to a loss of 21,700.0 kcal (90.3 MJ) or 362.0 kcal.d−1 (1.5 MJ.d−1). The mean (SD) energy expenditure by physical activity was 1,943.0 (653.8) kcal.d−1 (14.6 [2.7] MJ.d−1). The average (SD) total energy expenditure was 4,088.0 (710.0) kcal.d−1 (36.8 [3.8] MJ.d−1). Conclusion Tactical athletes must perform in hypo-energetic environment. Research in the future should investigate the impact of increased energy intake on body composition.