Background: During nocturnal sleep, blood pressure (BP) “dips” compared to diurnal B P, reducing stress on the cardiovascular system. Both the hypotensive response elicited by acute aerobic exercise and sleep quality can impact this dipping response. Purpose: The purpose of this study was to investigate the effects of aerobic exercise timing on circadian BP changes and sleep architecture. Materials and methods: Twenty prehypertensive subjects completed the study. During four test sessions, participants frst completed a graded exercise test to exhaustion and then performed 30 minutes of treadmill exercise at 7 am (7A), 1 pm (1P), and 7 pm (7P) in a random, counterbalanced order at 65% of the heart rate obtained at peak oxygen uptake. An ambulatory cuff was used to monitor BP responses during 24 hours following exercise, and an ambulatory sleep-monitoring headband was worn during sleep following each session. Results: Aerobic exercise at 7A invoked a greater dip in nocturnal systolic BP than exercise at 1P or 7 P, although the greatest dip in nocturnal diastolic BP occurred following 7 P. Compared to 1 P, 7A also invoked greater time spent in deep sleep. Conclusion: These data indicate that early morning may be the most beneficial time to engage in aerobic exercise to enhance nocturnal BP changes and quality of sleep.
Fairbrother, K., Cartner, B., Alley, J. R., Curry, C. D., Dickinson, D. L., Morris, D. M., & Collier, S. R. (2014). Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives. Vascular Health and Risk Management, 10, 691–698. https://doi.org/10.2147/VHRM.S73688