Association between heart rate variability and body composition in female rugby and volleyball players from Chilean Patagonia

Abstract

Objective: To describe the relationship between heart rate variability (HRV) parameters and body composition in female athletes training at high southern latitudes. Materials and Methods: A cross-sectional observational study with a correlational scope was conducted. Thirty-one female athletes (10 rugby players and 21 volleyball players) from the Magallanes and Chilean Antarctic Region participated. Body composition measurements consisted of bioelectrical impedance analysis (Tanita BC-558). HRV was recorded at rest using an H10 polar band and analyzed in the time and frequency domains with Kubios HRV. RMSSD, SDNN, HF, LF, VLF, PNS/SNS indices, and a stress index were calculated. Spearman's rank correlation coefficient was used to assess associations. Results: SDNN showed a positive association with muscle mass (r = 0.503, p < 0.01) and bone mass (r = 0.486, p < 0.01). RMSSD was associated with muscle mass (r = 0.408, p < 0.05). HF and LF showed moderate positive correlations with muscle mass (HF r = 0.358, p < 0.05; LF r = 0.450, p < 0.05). The PNS index correlated positively with muscle mass (r = 0.423, p < 0.05) and bone mass (r = 0.403, p < 0.05). In contrast, the SNS index and the stress index were negatively associated with muscle mass (SNS r = -0.475, p < 0.01; stress r = -0.559, p < 0.01) and bone mass (SNS r = -0.466, p < 0.01; stress r = -0.551, p < 0.01). Conclusion: In this sample of 31 female athletes, greater muscle mass and bone mass were associated with a more pronounced autonomic profile favoring parasympathetic activity (RMSSD, SDNN, HF, PNS index), while higher values ​​of the sympathetic and stress indices were associated with lower values ​​of muscle and bone mass. These results suggest that body composition, particularly muscle and bone mass, is linked to autonomic modulation in female athletes in high-latitude environments.