We’ve been told exercising can help improve sleep quality and may even be the cure for insomnia. So why were you staring at the ceiling until 3 a.m. last night (well, this morning) when you did a strength-training session yesterday at lunch? You may need to stick with that fitness routine for a while before you see snooze-time benefits, according to a new study.
Until now, researchers haven't been sure exactly why exercisers sleep better. So Kelly Glazer Baron, Ph.D., director of the behavioral sleep program at Northwestern University Feinberg School of Medicine, analyzed a small 2010 study of 11 women that showed that aerobic exercise improved sleep over a 16-week period. “The results of this new study tell us that exercise is not a quick fix for insomnia and that it takes a while to improve sleep," she says, adding that many factors are at play.
1. Consistency is key. In the study, the women exercised three or four times a week for at least 30 minutes at 75 percent of their maximum heart rate. Exercising on a single day didn't improve that night's sleep, but after 16 weeks of consistent exercise, all the participants were falling asleep faster and sleeping nearly an hour longer.
RELATED: 13 Expert-Approved Sleep Tips
2. Time of day matters. Baron says that exercising too close to bed can negatively affect sleep, so the study participants were instructed to do their exercise between 1 and 5 p.m. Of course, you can work out in the morning too, if that’s better for you, just don’t hit the gym after 5.
3. No need to kill it. In a 2010 study, Brazilian researchers found that while brisk walking helped participants fall asleep in half their usual time and sleep longer, higher-intensity activities such as running and weight lifting did not have the same effect.
4. Keep the cycle going. “Women exercised more after nights with better sleep,” Baron says. So exercise begets better sleep, which leads to more exercise, which results in even better sleep, and so on—all with time, remember.
5. Listen to Nike: Just do it. "People have to realize that when they don't want to exercise, 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!' because working out will help in the long run."