Differences of autonomic cardiac control in endurance and resistance trained male athletes

Abstract

The purpose of this study was to assess the result of the endurance- and the resistance-trained athletes on the adjustment of autonomic nervous system (ANS), controlling the heart rate, with spectral analysis of heart rate variability signals. The subjects were 60 males, aged between 20-25 years old, divided into 3 groups: 20 long-distance runners, 20 weightlifters, and 20 non-athlete subjects. The ECG signals were continuously recorded in 5 minutes from the subjects while taking the rest and performing ergometer at 50% V02max. ANS performance can be assessed by converting the ECG signals to two frequencies, which are the low frequency power (LF power between 0.04-0.15 Hz), related to sympathetic and parasympathetic performance and the high frequency power (HF power between 0.15-0.40 Hz), related to parasympathetic performance. It was found from the study that the long-distance runners had significant higher VO2max [63(9.52) ml/kg/min] than the weightlifters and non-athletes. The mean heart rate of the long-distance runners [56(8.01) /min] was significantly less than that of the weightlifters [65(6.92) /min] and non-athletes [68(8.79) /min], HF power of the long-distance runners while taking the rest [421(121) ms2] was higher than that of the weightlifters [241(72) ms2] and non-athletes [200(55) ms2] with significance. LF power of the long-distance runners [302(82) ms2] was significantly higher than that of non-athletes [231(70) ms2]; however, no significant difference was found, compared to the weightlifters. While exercising, LF and HF power significantly decreased, compared to the rest period. In addition, it was found no significant difference between HF and LF power in the exercise period, compared to other groups. The result indicates that the endurance training results more in enhancing the performance of parasympathetic activity, controlling heart rate, in the rest period than the resistance training.