Research of Heart Rate Variability in Sprinters
This article examines and analyses Heart Rate Variability (HRV) in short-distance runners. Sports are known to increase total HRV, with athletes having relatively higher variability than the general population. The Autonomic Nervous System (ANS) is divided into two subsystems: the sympathetic being activated during exercise and the parasympathetic during rest. In this research, their behaviour during training (physical exertion) can be considered stress for the body. During exercise, HRV decreases, RR intervals become shorter and more uniformand heart rate increases due to increased sympathetic and decreased parasympathetic activity. During rest and recovery, HRV begins to rise. The inability to return HRV to pre-exercise levels within a reasonable time is considered a chronic impairment in the activity of the ANS, which can lead to overtraining. Avoiding overtraining will improve athletes' athletic performance and prevent injuries. The application of spectral analysis performed the analysis of preand post-exercise HRV of 5 short-distance runners. Power spectral analysis represents the distribution of heart rate variation as a function of frequency. The frequencies used are Very Low (VLF), Low (LF) and High (HF), each of which is associated with a specific physiological cause. The assessment of HRV was made on 10-minute (two 5 minutes records) recordings recorded by an electrocardiographic device. From the performed experiment, it is noticed that the specifics of the behaviour of the autonomic nervous system and, from there, of the HRV of power runners differ from other athletes. The results of the analysis of HRV during athletes' training may be a valuable tool in evaluating the effects of athletes' activity, such as cumulative fatigue or improvement in cardiorespiratory fitness and exercise tolerance.