The relationship between resting heart rate variability and sportive performance, sleep and body awareness in soccer players

BACKGROUND: Heart rate variability (HRV) is a key marker of autonomic nervous system function and has been proposed as a tool for monitoring training adaptations. However, its relationship with performance beyond aerobic capacity remains unclear in football players. This study aimed to examine the associations between resting HRV and aerobic capacity, agility, neuromuscular coordination, sleep quality, and body awareness. METHODS: Twenty-five male football players (mean age 20 ± 3 years) underwent HRV assessment via the Polar H10 system. Performance tests included the 20 m Shuttle Test (VO2max), Illinois Agility Test, Hexagon Test (neuromuscular coordination), and Vertical Jump Tests (muscular strength). Sleep quality and body awareness were assessed using the Pittsburgh Sleep Quality Index and Body Awareness Questionnaire. RESULTS: HRV Score was positively correlated with VO2max (r = 0.4, p = 0.04), while LF/HF ratio showed a negative correlation with shuttle test distance (rs=-0.52, p = 0.007). Mean RR correlated with neuromuscular coordination (r = 0.56, p = 0.004), sleep quality (r = 0.45, p = 0.024), and body awareness (rs = 0.46, p = 0.019). No significant correlations were found with muscular strength. CONCLUSIONS: Resting HRV is associated with key performance indicators in football players, supporting its potential use in monitoring physiological readiness and training adaptations. Future research should establish reference values and evaluate HRV-based interventions for performance enhancement.