The Effects of Exercise and Stretching on Sleep In Postmenopausal Women

by Dr. Gregg D. Jacobs

Prior studies have documented that fit individuals sleep better than sedentary people.

A recent study published in the journal Sleep by Dr. Shelley Tworoger and her colleagues at the University of Washington School of Medicine examined the effects of a year-long moderate intensity exercise program and stretching program on the sleep of overweight, sedentary women ages 50-75 years.

Although the researchers expected that exercise would be more effective than stretching for improving sleep, they were surprised to find that stretching was also effective. They also found that the benefits of exercise depended upon the amount of exercise and at what time of the day. For example, morning exercisers who exercised at least three and a half hours per week (about 30 minutes per day) experienced improvements in their ability to fall asleep.

However, exercising less than a half-hour per day did not improve the ability to fall asleep. Evening exercisers who finished exercising at 7:30 p.m. and exercised for at least a half hour per day had more trouble falling asleep, probably because they exercised too close to bedtime and did not allow their body temperature to fall. However, these exercisers were more alert during the day and had more nights of sleeping more than six hours.

The stretchers exhibited a reduction in their use of sleep medication and fell asleep more easily. Exercisers who showed significant improvement in their physical fitness level (as measured by maximum oxygen consumption) exhibited improved sleep duration and less use of sleep medication. However, weight loss from exercise did not correlate significantly with improved sleep.

Prior studies have found that both relaxation techniques and exercise, particularly in the afternoon, improve sleep. These results of this study extend previous findings by suggesting that exercise or stretching in sedentary, overweight postmenopausal women improves sleep. Although these improvements in sleep were correlated with increased physical fitness (the more fit women became, the better they slept), they did not correlate with weight loss (women did not have to lose weight to sleep better).

Evening exercise (probably within three hours of bedtime) may disturb sleep but exercise in the morning, late afternoon, or perhaps early evening (at least three hours before bedtime) can improve sleep. Stretching can have the same beneficial effects on sleep, perhaps because stretching works in a similar manner to relaxation techniques.