(29) IMPACT OF BODY FAT CHANGE ON ACFT PERFORMANCE IN ROTC CADETS DURING AN ACADEMIC YEAR

Purpose: To assess the impact of BC changes over an academic year on ACFT performance among ROTC cadets. Methods: 60 ROTC cadets, 47 males (21.7±3.9 yrs;79.6±12.5 kg; BF%=19.0±5.5) and 13 females (19.1±1.0 yrs; 61.1±8.5 kg; BF%=23.5±4.8) completed the ACFT twice 6 months apart (times T1, T2). BF% was measured via handheld bioimpedance. T-tests compared BF%, FFM and ACFTt between T1 and T2. Agreement between ∆BC and ∆ACFT total score (ACFTt) was assessed using Cohen’s kappa (k, slight: 0-0.2; fair: 0.2-0.4; moderate: 0.4-0.6; substantial:0.6-0.8; near perfect: 0.8-1). ∆BC and ∆ACFT correlation was analyzed using repeated measures (RM) correlation (rmcorr R package) assessed 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: Mean T2 ACFTt was 516.8±46.4 and 507.9±54.3 in T1. T2 BF% was 19.7±6.3% (range 4.7-31.1%) and T1 was 20.0±5.7% (range 5.6-31.7%), while FFM was 61.0±10.2kg (range 39.2-81.6kg) in T2 and 60.2±10.8kg (range 36.0-80.9kg) in T1. No significant difference was observed between T1 vs. T2 in either ACFTt, BF%, or FFM (p>0.05). Among 31 cadets with reduced BF%, 24(77%) improved ACFTt; of 28 with increased BF%, 13(44%) improved ACFTt. Of 38 who increased FFM, 26 (68%) increased ACFTt, while of 22 with decreased FFM, 11 (50%) improved ACFTt (figure 1). There was fair kappa agreement for BF% (k=-0.3) and slight for FFM (k=0.18). The greatest event agreement was for standing power throw with BF% (k=-0.33) and FFM (k=0.28). Analysis of a subset of cadets with ∆BF% >3 (n=15), yields an increased moderate agreement between ACFTt and BF%(r=-0.51) and FFM(r=0.31). RM correlation between ∆BC and ∆ACFTt was insignificant (p>0.05) but near significant between ∆FFM and ∆Sprint-drag-carry event (r=0.25, p=0.054) and between ∆BF% and ∆2 mile run(r=0.23, p=0.069). Conclusions: While BC changes demonstrated fair to slight agreement with ACFT performance, a moderate relationship emerged in cadets with ∆BF% >3. Near-significant associations between ∆FFM and sprint-drag-carry performance and between ∆BF% and 2-mile run suggest BC differentiated influence. Longer-term studies of larger cohorts and ∆BC are needed to establish clearer guidelines as significant fitness adaptations may require more time to develop alongside ∆BC. Practical Applications: Factors beyond ∆BC (e.g., familiarization, targeted training, motivation) likely influence ACFT performance as ∆BC over a 6-month period have limited impact. ROTC programs should address event-specific training interventions due to differentiated BC influence. Acknowledgements: None