August 16, 2013
Insomniacs May Wait Months Before Exercise Offers A Good Night’s Rest
April Flowers for redOrbit.com - Your Universe Online
A common prescription for insomnia is exercise. However, according to a new Northwestern Medicine study, 45 minutes on the treadmill today will not translate into better sleep tonight.
"If you have insomnia you won't exercise yourself into sleep right away," said Kelly Glazer Baron, a clinical psychologist and director of the behavioral sleep program at Northwestern University Feinberg School of Medicine. "It's a long-term relationship. You have to keep at it and not get discouraged."
This study, which will be published in the current issue of the Journal of Clinical Sleep Medicine, is the first long-term study to show aerobic exercise during the day does not result in improved sleep that same night. The majority of studies concerning the daily effects of exercise and sleep have had healthy sleepers as test subjects.
The new study shows people exercise less following nights with worse sleep.
"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," said study coauthor Phyllis Zee, MD, the Benjamin and Virginia T. Boshes Professor of Neurology at Feinberg and director of the Sleep Disorders Center at Northwestern Memorial Hospital.
After hearing patients with insomnia complain the exercise she recommended didn’t help right away, Baron decided to analyze the daily effect of such exercise.
"They'd say, 'I exercised so hard yesterday and didn't sleep at all,'" Baron said. "The prevailing thought is that exercise improves sleep, but I thought it probably wasn't that simple for people with insomnia."
The researchers questioned why it takes so long for exercise to impact sleep.
"Patients with insomnia have a heightened level of brain activity and it takes time to re-establish a more normal level that can facilitate sleep," Zee said. "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 was conducted using older women as test subjects, as they have the highest prevalence of insomnia. Because drugs can cause memory impairment and falls, exercise is an optimum approach to promote sleep in an older population.
The results could also apply to men because, to date, there is no evidence of gender differences in behavioral treatments for insomnia.
The study findings came from an analysis of data from a 2010 clinical trial from the same group of Northwestern researchers. The prior research demonstrated the ability of aerobic exercise to improve sleep, mood and vitality over a 16-week period in middle-age-to-older adults with insomnia.
For the current study, the team examined the daily sleep data from 11 women ages 57 to 70.
Baron says the key finding of the current study is people with sleep disturbances have to be persistent with exercise.
"People have to realize that even if they don't want to exercise, that's the time they need to dig in their heels and get themselves out there," Baron said. "Write a note on your mirror that says 'Just Do It!' It will help in the long run."
The study group also included Kathryn Reid, research associate professor of neurology at Feinberg.