So, Go for It--High-Intensity Exercise Won’t Keep You Awake

For years, late-night exercise has gotten a thumbs-down, with many sleep experts contending that too much activity before bed can leave you too physiologically aroused to get a good night’s sleep.

But a small study done at the University of Georgia suggests the opposite.

Eight men--without insomnia or other sleep problems--engaged in high-intensity exercise for an hour, pedaling a stationary bike. They stopped about half an hour before going to bed.

On another night, they engaged in low-intensity exercise on the bike for an hour, again stopping half an hour before bedtime.

On a third night, they sat quietly and rested before bed.

The best night’s sleep followed the high-intensity workouts, says Patrick O’Connor, associate professor of exercise science at the University of Georgia, Athens, and one of the researchers who presented the data at a meeting of the American Psychological Assn.

“Based on this investigation,” he says, “it is concluded that late night, high-intensity exercise does not delay sleep onset, increase the number of nocturnal awakenings or reduce sleep efficiency even when sleep is initiated prior to complete physiological recovery from exercise.”

The findings apply only to “normal” sleepers, O’Connor cautions, adding that they probably apply to women as well.