HEART RATE VARIABILITY IS CORRELATED WITH RPE AND TRAINING LOAD IN ELITE SOCCER PLAYERS DURING AN ENTIRE COMPETITIVE SEASON

This study investigated the relationship between heart rate variability (HRV), rating of perceived exertion (RPE), and training load (TL) across an entire competitive season in elite soccer players. The purpose was to determine whether weekly average HRV values were correlated with subjective internal load indicators in order to better understand athletes’ readiness and fatigue management during a congested competitive calendar. Twenty-four outfield players competing in the Italian Serie A (2022/23 season) were monitored over 10 months. HRV was assessed using three-minute supine recordings with Firstbeat Sports sensors, while RPE (CR-10 scale) was collected after training sessions and matches. Training Load was calculated using the session-RPE method (training duration × RPE). A total of 2,419 HRV recordings were collected, with each player monitored on average 101 times during the season. Descriptive analysis revealed a relatively stable HRV trend throughout the season, while RPE and TL displayed greater variability, with peaks corresponding to periods of higher match congestion. Correlation analysis showed a moderate positive relationship between HRV and RPE (r = 0.48) and a stronger positive relationship between HRV and TL (r = 0.64). These findings suggest that HRV is meaningfully associated with internal load parameters across a competitive season. The results support the practical application of HRV as a non-invasive marker of physiological readiness in elite soccer, particularly when combined with subjective measures such as RPE and calculated training load.