The power spectral analysis of heart rate variability in athletes during exercise

In this study the effect of the autonomic nervous system (ANS) on heart rate variability (HRV) during dynamic exercise was assessed for 3 athletes and 7 nonathletes with power spectral analysis. The power spectrum of HRV was estimated using FFT and Burg´s Maximum Entropy Method. The activities of ANS were quantified by determining the parameters such as low frequency power (LFA), high frequency power (HFA) and their ratio. In pre-exercise, the HR in athletes was lower than one in nonathletes. This resulted from significantly higher HFA in athletes comparing to nonathletes. During exercise, LFA and HFA in both groups gradually decreased, which were progressively recovered during post-exercise, although remained below the pre-exercise level. Also, the recovery of HR during post-exercise was faster in athletes than in nonathletes. These results suggest that vagal activities in athletes play a major role not only in lowered HR during pre-exercise, but in rapid recovering of HR during post-exercise