Effects of post-exercise cooling on heart rate recovery in normotensive and hypertensive men

Background: Post-exercise heart rate recovery (HRR) is determined by cardiac autonomic restoration after exercise and is reduced in hypertension. Post-exercise cooling accelerates HRR in healthy subjects, but its effects in a population with cardiac autonomic dysfunction, such as hypertensives (HT), may be blunted. This study assessed and compared the effects of post-exercise cooling on HRR and cardiac autonomic regulation in HT and normotensive (NT) subjects. Methods: Twenty-three never-treated HT (43±8 ys) and 25 NT (45±8 ys) men randomly underwent two exercise sessions (30 min of cycling at 70%VO2peak) followed by 15 min of recovery. In one randomly allocated session, a fan was turned on in front of the subject during the recovery (cooling), while in the other session, no cooling was performed (control). HRR was assessed by heart rate reductions after 60 (HRR60s) and 300s (HRR300s) of recovery, short-term time constant of HRR (T30), and the time constant of the HRR after exponential fitting (HRRτ). HRV was assessed using time- and frequency-domain indices. Results: HRR and HRV responses in the cooling and control sessions were similar between the HT and NT. Thus, in both groups, post-exercise cooling equally accelerated HRR (HRR300s = 39±12 vs. 36±10 bpm, p≤0.05) and increased post44 exercise HRV (lnRMSSD = 1.8±0.7 vs. 1.6±0.7 ms, p≤0.05). Conclusion: Differently from the hypothesis, post-exercise cooling produced similar improvements in HRR in HT and NT men, likely by an acceleration of cardiac parasympathetic reactivation and sympathetic withdrawal. These results suggest that post-exercise cooling equally accelerates HRR in hypertensive and normotensive subjects

Association of Epstein-Barr virus antibody titers with a human IL-10 promoter polymorphism in Japanese women

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