Sleep researchers have some good news: insomnia is among the many adverse health conditions treatable with increased levels of physical activity.

Dr. Shawn Youngstedt, a sleep researcher at the University of California, San Diego, goes as far as to say exercise can provide positive effects similar to those provided by sleeping pills, which are also notorious for next-day drowsiness and other side effects.

"People should experiment for themselves to see whether exercise promotes better sleep," Youngstedt says. "Sleep-deprived individuals should even try experimenting with different intensities of exercise at different times of the day."

Deeper sleep stages

This is why exercising is so important to a good night’s sleep: physical activity may mean that you spend more time in the deeper stages of sleep, when you are less likely to be awakened by the slightest noise. What’s more, you’ll probably take less time to fall asleep than a person who doesn’t exercise at some point in the day.

Sleep researchers say moderate exercises lasting 20 to 30 minutes, three or four times a week will help you sleep better and give you more energy. Of course, you can exercise as vigorously as you want and for as long as you want, if such activity fits into your overall healthy-living plans.

Basically, exercise helps your brain ratchet up the chemical epinephrine, which keeps you alert and raises your body temperature. Five or six hour later – just about the time you’re ready for bed – your temperature will plunge, which makes falling – and staying – asleep much easier.

Researchers at Stanford University’s medical school in Palo Alto, Calif., studied the effects of exercise on sleep patterns of adults ages 55 to 75 who were sedentary and plagued by insomnia. In the study, the adults walked, engaged in low-impact aerobics, or rode a stationary bike for 20 to 30 minutes every other day.

Falling asleep in half the time

As a result, they slashed their time required to fall asleep in half and boosted the amount of shut-eye by almost an hour.

In his own research, Youngstedt found that your body’s circadian rhythms – in other words, your “body clock” – are the brain's natural way of telling you when to sleep and when to be active. Since exercise promotes shifts in the body clock, physical activity may help you overcome sleep problems related to a screwed-up body clock, such as problems associated with working odd or varying hours.

Youngstedt also says exercising outdoors may add to the benefits because light exposure has sleep-promoting and anti-depressant effects.
 
The best time to exercise is either in the morning or in the afternoon, just not too close to when you hit the sack. Generally, experts with the Washington, D.C.-based National Sleep Foundation caution to avoid strenuous exercise right before you climb into bed and even up to three hours before bedtime.

You may wonder how you’ll fit exercise into your busy life. Try this: a brisk walk or bike ride in the afternoon instead of a caffeine-laced coffee break that may affect your sleep quality later that night. You may also think about an aerobic exercise that increases your heart rate, such as running, jogging, skipping rope, or an aerobics class – and throw in a weight-bearing workout.