Q
Is there anything wrong with exercising — light cardio and calisthenics, for instance — before bedtime?
Asked by Leslie • 30 votes
A
The short answer is no. “Light exercise and stretching before bed are probably a good thing,” said Christopher Colwell, a neuroscientist and professor of psychiatry at the David Geffen School of Medicine at the University of California, Los Angeles, who studies the neurobiology of sleep.
Many people believe that evening exercise will undermine sleep, but there’s little scientific evidence to support that idea, especially if the activity isn’t too taxing, such as walking the dog or attending a mellow yoga class after dinner.
On the other hand, “I would not recommend a heavy cardio workout within an hour or two before bed,” Dr. Colwell said in an e-mail. Mouse experiments in his lab suggest that when mice run for prolonged periods in the equivalent of their nighttime (chronologically opposite of ours; mice are nocturnal), their natural circadian rhythms become unsettled and they don’t sleep as soundly.
His research suggests that a similar effect could apply to humans, though not to everyone. “There will be some people that will tell you that they go for a run, come home and sleep like a baby,” Dr. Colwell said. “If this works for them, no reason to change. Others will do the same workout and not be able to sleep” for two or three hours, he said. “The best advice here is to know yourself.”
Finally, if your concern is with athletic performance and not sleep patterns, you might want to complete your workout earlier in the day, but not too much earlier. In a 2012 study of 20 Tunisian soccer players, the athletes performed best on tests of speed and endurance at 5 p.m.
Do you have a question about fitness? Ask Gretchen Reynolds, and you may be included in The New York Times Magazine’s upcoming Health Issue.