(21) MALES EXHIBIT STRONGER CORRELATIONS BETWEEN BODY COMPOSITION VARIABLES AND ACFT PERFORMANCE THAN FEMALE ROTC CADETS

Introduction:  The United States Army recently introduced a new fitness assessment, the Army Combat Fitness Test (ACFT), which places a greater emphasis on power and strength than the previous fitness assessment that emphasized muscular and aerobic endurance. The ACFT comprises six components: 3 Repetition Maximum Deadlift (MDL), Standing Power Throw (SPT), Hand-Release Push-up (HRP), Sprint-Drag-Carry (SDC), Plank Hold Time (PLK), and 2 Mile Run (2MR). US Army Reserve Officers’ Training Corps (ROTC) cadets are expected to maintain acceptable fitness scores on the ACFT. Previous research suggests a correlation between ACFT performance and body composition (BC) variables. However, little is known how these correlations differ between males and females, especially considering the recent Army’s policy to exempt high performers from body fat % (BF%) assessment. 

Purpose:  To assess sex differences in ACFT performance correlations with BC variables among ROTC cadets. 

Methods:  A total of 73 male (age=21.5±3.8 yrs, mass=79.7± 3.1kg, BF%=18.6±5.6) and 24 female (age=19.5±1.3yrs, mass=63.5±8.6kg, BF%=25.1±4.8) ROTC cadets completed the ACFT. BF% was collected on site using a handheld bioimpedance device. BC variables included: total mass, BF%, Body Mass Index (BMI), fat free mass (FFM), FFM to fat mass ratio (FFM:FM), and FFM index (FFMI) calculated as FFM/height². Student’s t-tests were performed between sexes for all ACFT raw performance components and Pearson correlations were computed between ACFT raw scores and the BC variables for males and females separately. Correlations were classified as: 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) 

Results:  Males exhibited at least one significant correlation (p< 0.05) between BC variables and each ACFT component while females only with PLK and MDL (table 1). In males, large correlations were found between MDL and Mass, BMI, FM, and FFM and a very large correlation (0.71) with FFMI. Large correlations were found between SPT and mass, FFM, and FFMI. SDC was moderately correlated with FFM (-0.41). Females exhibited large correlations only between PLK and total mass, BF%, BMI, and FM. 

Conclusions:  The findings indicated that males generally had greater influence of BC on ACFT performance than females. These differences may also reflect additional influential variables other than BC; however, the study design did not allow for confounding variables to be identified. Future research should investigate potential confounding factors, other than BC, that can influence sex differences in ACFT performance. PRACTICAL APPLICATIONS: These findings suggest that BC is not a prerequisite to high performance and are supportive of the 2023 Army’s directive exempting high performance soldiers (score³80 in each event and total score³540) from BF% assessment. Furthermore, the findings support the possibility that females can be high performers despite higher fat %.

Acknowledgements: None