Study: Early exercise best for reducing blood pressure
It may seem counter intuitive, but if you need to lower your blood pressure and also want a good night's sleep, 7 a.m. is the best time to exercise.
Appalachian State University's Dr. Scott Collier is researching the various beneficial effects of exercise on blood pressure. Collier is an assistant professor in the Department of Health, Leisure and Exercise Science in Appalachian's College of Health Sciences.
He and student research assistants Kimberly Fairbrother and Ben Cartner tracked blood pressure levels and sleep patterns of individuals ages 40 to 60, who exercised moderately for 30 minutes, three times a week. The research volunteers walked on a treadmill at 7 a.m., midday (1 p.m.) and in the evening (7 p.m.).
In all cases, those who exercised at 7 a.m. experienced about a 10 percent reduction in blood pressure that carried through the remainder of the day. They also had about a 25 percent dip in blood pressure at night, slept longer and had more beneficial sleep cycles than when they exercised at other times of the day.
Collier's team presented their research findings at the recent annual meeting of the American College of Sports Medicine and the Second World Congress on Exercise is Medicine in Denver, Colo.
Collier's focus on time of exercise was spurred by medical data indicating that most people have heart attacks early in the morning. He wants to know how this may be prevented.
"We know a rush of hormones is released when a person first awakens in the morning that raises blood pressure," he said. "Can this result in some type of cardiac myopathy or can we alleviate this condition?"
High blood pressure also impacts sleep.
"Our blood pressure dips at night which helps reset the body, keeping blood pressure within a certain range and relaxing vasculature and the heart," Collier said. "We know the long-term clinical manifestations of poor sleep include hypertension and myocardial infarction or heart attacks. Also, obesity and diabetes can be related to poor sleep. We wanted to know if there could be a best benefit of exercise related to improved blood pressure."
Collier had expected evening exercise to show the best benefit.
"Much to our surprise, 7 a.m. exercise was better in terms of reduced blood pressure throughout the day and greater sleep benefits than exercise at 7 p.m., and there was little blood pressure or sleep benefit when exercise was done at 1 p.m.," he said. "We don't yet know the physiological mechanisms that result in these changes, but we do know enough to say if you need to decrease your blood pressure and if you need to increase your quality of sleep, 7 a.m. is probably the best time to exercise."
Collier next will study individuals who exercise at different times of the day to determine if changes in hormone secretion are impacting their blood pressure levels.
Collier previously documented the beneficial effects of resistance training in lowering blood pressure. That study was published in the Journal of Strength and Conditioning Research.