(27) INFLUENCE OF FAT-FREE MASS ON ARMY COMBAT FITNESS TEST AND EXPLOSIVE PERFORMANCE IN ROTC CADETS

Purpose: To examine the relationships between fat-free mass, Army Combat Fitness Test (ACFT) performance, and metrics of explosive performance in Reserve Officers’ Training Corps (ROTC). Methods: 179 ROTC cadets (male=134, female=45, age=21.0±4.2yrs, mass=74.4±14.1kg, BF%=20.9±7.6) completed body composition assessments via Bioelectrical impedance to determine fat-free mass. Explosive performance metrics of peak power and peak force were assessed using a counter movement jump performed on a force plate. ROTC cadets completed the ACFT on a separate day within 48-72 hours of the physical fitness testing. The ACFT assesses active-duty army personnel and (ROTC) cadets' physical readiness across six events: three-rep maximum deadlift (MDL), standing power throw (SPT), hand-release push-up (HRP), sprint-drag-carry (SDC), plank hold (PLK), and two-mile run (2MR). Standard United States Army procedures were followed for ACFT testing. Pearson’s correlation coefficient (r) assessed the relationship between fat-free mass, ACFT performance, and physical fitness measures. Hopkins scale was used to qualify the correlations (trivial: 0–0.1; small: 0.1–0.3; moderate: 0.3–0.5; large: 0.5–0.7; very large: 0.7–0.9; near perfect >0.9). Statistical significance was set to p< 0.05. Results: Descriptive statistics and correlations are provided in Table 1. Fat-free mass showed significant correlations with all ACFT scores and physical fitness metrics, except for PLK (r=0.05, p=0.476). Large, positive correlations were found between MDL (r=0.75, p< 0.001), and peak power (r=0.74, p< 0.001), indicating higher fat-free mass is strongly associated with explosive performance measures. SDC performance (r=-0.70, p< 0.001) showed a strong, negative correlation, suggesting faster times with increased fat-free mass. Smaller, but significant correlations were found with HRP (r=-0.28, p< 0.001), 2MR (r=-0.15, p=0.040), and concentric peak force (r=0.17, p=0.028). Conclusions: Results indicate that fat-free mass positively influences performance in most ACFT events and fitness metrics, particularly power-based tasks such as the SPT and peak power. The strong correlations with MDL performance and SDC time suggest fat-free mass contributes to both strength and anaerobic capacity. Practical Applications: Increasing fat-free mass may enhance performance in strength and power-based tasks within the ACFT. Strength and hypertrophy focused programs could be beneficial for US Army ROTC cadets. Although the sample was comprised of ROTC cadets, these insights could help strength and conditioning professionals optimize training programs to support combat readiness and occupational performance in military settings. Acknowledgements: None