Heart Rate Variability in Sports: From Monitoring to Maximizing Recovery and Performance

Background: Heart Rate Variability (HRV) is a non-invasive biomarker reflecting autonomic nervous system balance and is increasingly used in sports science to monitor training and recovery. Objective: This systematic review aims to investigate the effects of HRV on exercise performance and post-exercise recovery based on studies published between 2020 and 2025. Methods: The review followed PRISMA guidelines and included 42 peer-reviewed articles selected from PubMed, Scopus, Web of Science, SPORTDiscus, and Embase. Results: Studies revealed that higher HRV values (especially RMSSD and SDNN) before and after exercise are associated with enhanced performance and faster recovery. HRV was also effective in monitoring training load, fatigue, and autonomic adaptation in athletes. Conclusion: HRV can be considered a practical and valid tool for optimizing athletic performance and monitoring physiological recovery in various exercise modalities.