What is the clinical evidence from this study?

Study design: Cross-Sectional. Population: Healthy (athletes vs nonathletes) (n=30). Intervention: Endurance training (athlete status) vs. Nonathletes. Primary outcome: High frequency (HF) power in RR interval spectra.

November 1, 1997

Autonomic differences between athletes and nonathletes: spectral analysis approach

Key Result

Endurance training in athletes was associated with significantly higher high-frequency power in RR interval spectra compared to nonathletes, indicating enhanced vagal activity.

Study Design

Type

Cross-Sectional (n=30)

Structured PICO

Does endurance training alter autonomic function and baroreflex sensitivity in athletes compared to nonathletes?

Population

30 individuals, comprising 15 athletes and 15 nonathletes, assessed for autonomic function during 10 minutes of sitting.

Exposure

Endurance training (athlete status)

Comparator

Nonathlete status

Outcome

Autonomic function assessed by low frequency (LF) and high frequency (HF) power of RR interval, systolic and diastolic arterial pressure variability, and spontaneous baroreflex sensitivitysurrogate

Endurance training is associated with enhanced vagal activity, which may partially explain resting bradycardia in athletes.

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.

Bookmark