Clinical & Experimental Cardiology
Open Access

Abstract

Reduced Room for Cardiac Vagal Modulation to Increase and Cardiac Sympathetic Modulation to Decrease by Resting in Football Players

Wan-An Lu, Yu-Chung Chen and Cheng-Deng Kuo

Background: This study investigated the cardiac autonomic nervous modulation of football (soccer) players at rest, and whether resting can change it further.

Methods: The stationary state spectral heart rate variability (HRV) measures at rest and 60 and 90 min after baseline measurement were compared between football players and sedentary controls. The percentages of change in HRV measures 60 and 90 min after baseline measurement were also compared between football players and sedentary controls.

Results: Seventeen football players and 17 sedentary normal subjects were recruited in this study. The total power (TP), very low frequency power (VLFP), low frequency power (LFP), high-frequency power (HFP) and normalized high-frequency power (nHFP) of football players at rest were all significantly higher, while both normalized low-frequency power (nLFP) and low-/high-frequency power ratio (LHR) of football players at rest were significantly lower than those of normal controls. Sixty and 90 min after baseline measurement, though the heart rate (HR) was significantly decreased and the standard deviation of RR intervals (SDRR), root mean squared successive difference (rMSSD), TP, VLFP, and HFP were all significantly increased in the control group, there were no significant changes in the HRV measures except that the HR was slightly decreased in the football players.

Conclusion: The football players have increased vagal modulation and decreased sympathetic modulation at rest as compared to sedentary non-athletes. Although vagal modulation can be increased significantly by resting in the sedentary non-athlete, it cannot be increased significantly in the football players. The football players at rest seem to be already in a relatively relaxed state which cannot be relaxed further by further resting, whereas the nonathletes are not relaxed fully at rest and more rest can lead to further relaxation. The room for cardiac vagal modulation to increase and cardiac sympathetic modulation to decrease by resting is reduced in the football players relative to that of normal subjects.