Effects of seasonal training on physical fitness and heart rate variability in amateur Futsal players

Abstract

Amateur futsal training, particularly in university settings, often faces limitations in training load regulation and recovery management, which may increase the risk of accumulated fatigue and maladaptive physiological responses. This study aimed to examine within-subject changes in physical fitness and heart rate variability (HRV) across pre-season and in-season training phases in amateur futsal players. Twenty male university-level futsal players completed physical fitness assessments and resting HRV measurements at three time points: baseline, after a 6-week pre-season, and after a 6-week in-season training period. Physical fitness variables included countermovement jump (CMJ), 10-m sprint performance, aerobic capacity assessed by the Beep Test (estimated VO₂max), and repeated shuttle sprint ability. Internal training load was monitored using the session rating of perceived exertion (session-RPE) method. Data were analyzed using repeated-measures analysis of variance, with statistical significance set at p < 0.05. The pre-season phase was characterized by higher training load, monotony, and strain, which were associated with stagnation or reductions in selected physical fitness variables and unfavorable autonomic responses. In contrast, the in-season phase, marked by reduced training load and monotony, resulted in significant improvements in physical fitness and a more favorable autonomic balance. These findings indicate that seasonal training structure plays a critical role in shaping physical fitness adaptations and autonomic regulation in amateur futsal players. Monitoring HRV in conjunction with training load may serve as a practical approach for optimizing training management and supporting recovery throughout the competitive season.