Improving the functional status of young boxers in the preparatory period of training with biofeedback.

There is little systematic research on how the training load of an athlete in the preparatory period affects their functional state. This study aims to develop and test a new targeted training method for improving the functional state of boxers aged 15-16 (15.6 ± 0.5) years using heart rate variability (HRV) biofeedback. A total of 50 teenage male athletes participated in the study. The proposed program involved biofeedback-based physical training coupled with breathing and emotional regulation exercises. Here, the functional status assessment involved psychological (attention, working memory, physiological stress), neurodynamic (simple sensorimotor reaction, maximal voluntary strength, strength endurance of the wrist flexor muscles), and neurovegetative (stress index, reactivity and tension indicators of regulatory systems) variables. The results demonstrated significant improvements in attention (Cohen's d = 3.85) and working memory (Cohen's d = 2.12) and a decrease in physiological stress (Cohen's d = 0.87) in the HRV-BF group compared to the control group. The proposed framework can be integrated into boxer training programs in youth sports schools and specialized training centers, as it contributes not only to enhancing cognitive characteristics but also to optimizing neurovegetative balance through the reduction of physiological stress. Future research should focus on clarifying the effectiveness of HRV-BF in sustaining the stability of regulatory systems under conditions of intensive physical load.