Long Duration Load Carriage Performance Is Associated With Army Combat Fitness Test Scores and Fat-Free Mass.

Abstract: Sax van der Weyden, M, Merrigan, JJ, and Martin, J. Long duration load carriage performance is associated with Army Combat Fitness Test scores and fat free mass. J Strength Cond Res 38(11): 1959-1966, 2024-A common occupational task for the military is carrying heavy loads for long periods of time. The US Army has set a time standard of 3 hours to complete a 19.31-km march with a 15.9-kg ruck sack for combat arms training and specialty schools. The purpose of this study was to identify characteristics associated with 19.31-km foot march completion rates in Reserve Officers' Training Corps (ROTC) Cadets. Demographics, anthropometrics/body composition, Army Combat Fitness Test (ACFT) scores, and vertical countermovement jump (CMJ) data were collected on 65 ROTC cadets who conducted a 19.31-km foot march. Independent t tests and Mann-Whitney U tests compared variables between those who did and did not finish the foot march in less than 3 hours. Logistic regressions were used to calculate the odds of completing the foot march using military experience, fat-free mass, ACFT, and CMJ outcomes. Cadets who met the 3 hours standard had lower body fat percent, greater fat-free mass, higher ACFT scores, and higher CMJs than those who did not. In addition, for every one point increase in ACFT score and 1-kg increase in fat-free mass, a cadet's chances of finishing the foot march increased by 6.1 and 24%, respectively. When analyzing ACFT events separately, 2-mile run was the only significant variable, and for every 1 point increase in 2-mile run score, a cadet's chances of finishing the foot march increased by 9%. Thus, aspiring and current soldiers should train to improve aerobic fitness and build muscle mass in preparation for load carriage requirements.