Autonomic cardiac and cardiorespiratory responses in volleyball athletes compared to recreationally trained individuals

Abstract

The aim of this study was to investigate the autonomic cardiac modulation between professional volleyball players (VP) and recreational aerobically trained individuals (RAT). Methods: Twentyeight men were divided into two groups, (VP; n = 14) and (RAT; n = 14) and each group was subjected to a sub-maximal progressive ramp treadmill test. Cardiac cycle beat to beat (RR) intervals, was obtained through electrocardiogram recording with the test being stopped when the individual reached 85% of their maximum age-predicted heart rate (HR). The heart rate variables were calculated from ECG using MATLABbased algorithms. Results: At rest, RAT showed lower values of the mean value of RR interval, the root mean square successive difference of all RR intervals (r-MSSD), low frequency (LF) and total power spectral (TP) when compared to VP. No significant difference between groups was noted for high frequency (HF) and index LF/HF. After exercise, no significant differences were measured between groups. Mean values of VO 2 , V E /VO2, and V E showed no significant difference at rest and post effort. Conclusion: The variables such as frequency, intensity and volume may to interfere the autonomic cardiac modulation and possibly indicating a superior protection against exercise-induced ventricular arrhythmias and lower risk of sudden cardiac deaths.