Effects of regular aerobic exercise on post-exercise vagal reactivation in young female.

Regular aerobic exercise accelerates post-exercise cardiovagal reactivation. However, little is known about the potentially favourable modulatory effects of regular aerobic exercise on cardiovagal reactivation in young female. The purpose of this study was to examine effects of regular aerobic exercise on post-exercise vagal reactivation in young female. Our study consisted of 8 female endurance-trained athletes (athlete group) and 10 untrained females (control group). Resting heart rate (HR), HR variability and post-exercise cardiovagal reactivation were measured during the subjects' early follicular (EF) and middle luteal (ML) phases. Post-exercise cardiovagal reactivation was estimated by T30: the time constant of HR decline for the first 30 s after the 4-min cycle ergometer exercise (intensity: 80% of ventilation threshold). In both groups, T30 was more accelerated in the EF phase than in the ML phase (P<0.05). In the EF phase, T30 was lower in the athletes than in the controls (P<0.05). A significant correlation between maximum oxygen uptake (VO2max) and T30 was observed in the EF phase (r=0.545, P<0.05). Our results suggest that regular aerobic exercise accelerates post-exercise cardiovagal reactivation in the EF phase in young female.