Autonomic differences between athletes and nonathletes: spectral analysis approach

Abstract

The purpose of this study was to assess the adaptive effects of endurance training on autonomic function in athletes with spectral analysis of cardiovascular variability signals. Continuous ECG, arterial blood pressure (ABP), and respiratory signals were recorded from 15 athletes (VO2max > 55 mL.min-1.kg-1) and 15 nonathletes (VO2max < 45 mL.min-1.kg-1) during 10 min at sitting position. Autonomic function was assessed by low frequency power (LF power: 0.06-0.14 Hz) and high frequency power (HF power: the region of the respiratory frequency based on respiratory spectrum) obtained from the autospectra of RR interval, systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) variability signals. The spontaneous baroreflex sensitivity was evaluated by the moduli, BRSLF and BRSHF, of the transfer function between RR interval and SAP variability in LF and HF bands. The resting HR in athletes was significantly lower than that in nonathletes. The HF power, an index of parasympathetic activity, in RR interval spectra were significantly higher in athletes than in nonathletes. Meanwhile, the LF power (an indicator of sympathetic activities contributing to RR interval and of ABP variabilities) showed no significant difference between both groups, although that of athletes was slightly less than that of nonathletes. Also, BRSLF and BRSHF were not significantly different between athletes and nonathletes. These results indicate that endurance training results in the enhanced vagal activities in athletes, which may contribute in part to the resting bradycardia.

Time domain and frequency domain analysis of heart rate variability in elite Nepalese football players

“…Alterations in the cardiac autonomic balance and changes in the intrinsic mechanisms acting on the sinus node are reported to contribute to this phenomenon. Human studies that have used cardiac autonomic blockade to investigate the effect of training on autonomic balance, reported the enhanced parasympathetic and/or diminished sympathetic activity on heart might contribute in part to the resting bradycardia [6,12]. The present study also indicates alterations in the autonomic control of the heart as it was evident by HRV analysis.…”

“…Some have shown that endurance-trained subjects present higher values of power spectral HRV, indicating increasing vagal activity [6,7]; others have reported higher values of the LF component of HRV suggesting higher sympathetic activity [8]. Lower levels of sympathetic IJBR (2015) 6 (09) www.ssjournals.com activation [9] and vagal activation [8] and, finally, no differences have been found between trained and untrained subjects [10].…”

Effects of aerobic exercise training on heart rate variability during wakefulness and sleep and cardiorespiratory responses of young and middle-aged healthy men

“…While some studies have reported an increase in the magnitude of this variable in the time domain (9), in the frequency domain others have reported absence of modifications (10), and an increase (11) or decrease (12) of sympathovagal balance in the sinus node.…”

Autonomic response to exercise as measured by cardiovascular variability

“…It is known that endurance athletes have lower average resting heart rates than non-exercising individuals. 33,50 However, other exercise-induced autonomic influences on cardiac control are far more controversial.Autonomic control via sympathetic and parasympathetic modulation of the heart has been assessed by power spectral analysis of HRV 1,7,33,41,46,48,50 and BPV. 44,52 Different frequency peaks reflect specific physiological stimuli and it is possible to estimate the involvement of the autonomic nervous system (ANS) influence and balance in heart rate (HR) regulation.…”