Exercise is a common prescription for insomnia.
But if you have trouble sleeping, spending 45 minutes exercising one day won't translate into better sleep that night, according to research done at Northwestern University in the US.
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 a night with disrupted sleep.
It appears sleeping poorly doesn't change your aerobic capacity, but it changes your perception of effort and exertion so you feel more fatigued.
The study showed that 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.
Why does it take time for exercise to impact sleep?
People with insomnia usually have a raised level of brain activity and it takes time to re-establish a more normal level that can facilitate sleep.
The researchers believe that rather than medications, which can induce sleep quickly, exercise may be a healthier way to improve sleep because it could address the underlying problem.
The study participants were older women, who have the highest prevalence of insomnia. Exercise is an optimum approach to promote sleep in an older population because drugs can cause memory impairment and falls.
The key message is that people with sleep disturbances, no matter what age, have to be persistent with exercise.
Even if you don't want to exercise, that's the time you need to push yourself out the door and get moving.
In the long term you'll be glad you did.
Article Author: David Beard, Calico's Exercise Physiologist & Healthy Aging Expert
