Relationship between body composition, anxiety and cardiac autonomic modulation in high-latitude combat athletes: analysis by sex.

Abstract

Objective: To analyze the relationship between body composition, state-trait anxiety and cardiac autonomic modulation in combat athletes living at high southern latitudes, with sex-based comparisons. Method: Cross-sectional observational study including 42 combat athletes (31 men and 11 women; 15-34 years). Anxiety was assessed with the State-Trait Anxiety Inventory, body composition by segmental bioimpedance, and resting heart rate variability (HRV) using a Polar H10 chest strap. Wilcoxon rank-sum tests and Spearman correlations were applied. Results: Women showed a higher body fat percentage (28.15% vs. 10.90%; p < 0.001) and higher high-frequency power (859 vs. 449 ms2; p = 0.013). Total muscle mass was positively associated with mean RR interval (rho = 0.32; p = 0.041) and negatively associated with mean heart rate (rho = -0.31; p = 0.046) and HF power (rho = -0.34; p = 0.031). Body fat percentage was negatively associated with low-frequency power (rho = -0.37; p = 0.018). No significant correlations were observed between anxiety scores and body composition or HRV markers. Conclusion: In combat athletes living at high southern latitudes, body composition is associated with resting cardiac autonomic markers, with differential patterns according to sex. Resting state-trait anxiety showed no significant associations with HRV or body composition.