Exercise no quick fix remedy for insomnia

Although exercise has been commonly prescribed for insomnia, spending 45 minutes on the treadmill for one day won't translate into better sleep that night, a new study suggests.

"If you have insomnia you won't exercise yourself into sleep right away," lead study author Kelly Glazer Baron, a clinical psychologist and director of the behavioral sleep program at Northwestern University Feinberg School of Medicine, said.

"It's a long-term relationship. You have to keep at it and not get discouraged," she said.

This is the first long-term study to show aerobic exercise during the day does not result in improved sleep that same night when people have existing sleep problems.

Most studies on the daily effects of exercise and sleep have been done with healthy sleepers.

The study also showed people exercise less following nights with worse sleep.

"Sleeping poorly doesn't change your aerobic capacity, but it changes people's perception of their exertion," Baron said.

"They feel more exhausted," she said.

"This new study shows exercise and sleep affect each other in both directions: regular long-term exercise is good for sleep but poor sleep can also lead to less exercise. So in the end, sleep still trumps everything as far as health is concerned," senior author Phyllis Zee, M.D., said.

The study is set to be published in the Journal of Clinical Sleep Medicine.