Comparison of morning versus evening aerobic-exercise training on heart rate recovery in treated hypertensive men: a randomized controlled trial

Heart rate recovery (HRR) is a marker of cardiac autonomic regulation and an independent predictor of mortality. Aerobic-exercise training conducted in the evening (evening training) produces greater improvement in resting cardiac autonomic control in hypertensives than morning training, suggesting it may also result in a faster autonomic restoration postexercise. This study compared the effects of morning training and evening training on HRR in treated hypertensive men. Forty-nine treated hypertensive men were randomly allocated into three groups: morning training, evening training and control. Training was conducted three times/week for 10 weeks. Training groups cycled (45 min, moderate intensity) while control group stretched (30 min). In the initial and final assessments of the study, HRR60s and HRR300s were evaluated during the active recovery (30 W) from cardiopulmonary exercise tests (CPET) conducted in the morning and evening. Between-within ANOVAs were applied (P <= 0.05). Only evening training increased HRR60s and HRR300 differently from control after morning CPET (+4 +/- 5 and +7 +/- 8 bpm, respectively, P < 0.05) and only evening training increased HRR300s differently from morning training and control after evening CPET (+8 +/- 6 bpm, P < 0.05). Evening training improves HRR in treated hypertensive men, suggesting that this time of day is better for eliciting cardiac autonomic improvements via aerobic training in hypertensives.

Automated summary

Evening training improves heart rate recovery in treated hypertensive men, indicating that this time of day is more effective for enhancing cardiac autonomic function through aerobic exercise in hypertensive individuals.