Answered by on Monday, October 26, 2009
Do you often find yourself running on the treadmill at 9 p.m. and wondering if you're really supposed to be doing this in daylight hours? Good news, 24-hour fitness buffs. It doesn't matter when you choose to exercise. "In terms of the beneficial aspects of exercise, it doesn't matter when it happens," says Tim White, Ph.D., dean of Oregon State University's College of Health and Human Performance and president of the American College of Kinesiology. "The most important thing is that it happens." People have different circadian (24-hour) rhythms hardwired in their bodies which will influence how they feel during exercise, explains Declan Connolly, Ph.D., director of the University of Vermont's Human Performance Lab. As a rule, however, Connolly cautions that "stretching exercises involving the spine should not be done first thing in the morning because the water content (and thus the pressure) in the disks is three times higher following sleep." He advises that you hold off doing such stretches for at least 30 minutes after you get up in the morning.