WASHINGTON, March 4, 2013 /PRNewswire-USNewswire/ -- Exercise can affect your sleep. The results of the National Sleep Foundation's 2013 Sleep in America® poll show a compelling association between exercise and better sleep. "Exercise is great for sleep. For the millions of people who want better sleep, exercise may help," says David Cloud, CEO of the National Sleep Foundation (NSF). Exercisers say they sleep betterSelf-described exercisers report better sleep than self-described non-exercisers even though they say they sleep the same amount each night (6 hours and 51 minutes, average on weeknights). Vigorous, moderate and light*exercisers are significantly more likely to say "I had a good night's sleep" every night or almost every night on work nights than non-exercisers (67%-56% vs. 39%). Also, more than three-fourths of exercisers (76%-83%) say their sleep quality was very good or fairly good in the past two weeks, compared to slightly more than one-half of non-exercisers (56%). "If you are inactive, adding a 10 minute walk every day could improve your likelihood of a good night's sleep," says Max Hirshkowitz, PhD, poll task force chair. "Making this small change and gradually working your way up to more intense activities like running or swimming could help you sleep better." "Our poll data certainly find strong relationships between good sleep and exercise," adds Hirshkowitz. "While cause and effect can be tricky, I don't think having good sleep necessarily compels us to exercise. I think it is much more likely that exercising improves sleep. And good sleep is fundamental for good health, productivity, and happiness." Vigorous exercisers report the best sleepVigorous exercisers are almost twice as likely as non-exercisers to report "I had a good night's sleep" every night or almost every night during the week. They also are the least likely to report sleep problems. More than two-thirds of vigorous exercisers say they rarely or never (in the past 2 weeks) had symptoms commonly associated with insomnia, including waking up too early and not being able to get back to sleep (72%) and difficulty falling asleep (69%). In contrast, one-half (50%) of non-exercisers say they woke up during the night and nearly one-fourth (24%) had difficulty falling asleep every night or almost every night. "Poor sleep might lead to negative health partly because it makes people less inclined to exercise," says Shawn Youngstedt, PhD, poll task force member. "More than one half (57%) of the total sample reported that their activity level will be less than usual after a night of poor sleep. Not exercising and not sleeping becomes a vicious cycle." Non-exercisers are the sleepiest and have the highest risk for sleep apneaNon-exercisers tend toward being more excessively sleepy than exercisers. Nearly one-fourth of non-exercisers (24%) qualify as "sleepy" using a standard excessive sleepiness clinical screening measure. This sleepiness level occurs about twice as often than for exercisers (12-15%). Also, about six in ten of non-exercisers (61%) say they rarely or never have a good night's sleep on work nights. Sleepiness clearly interferes with many non-exercisers' safety and quality of life. One in seven non-exercisers (14%) report having trouble staying awake while driving, eating or engaging in social activity at least once a week in the past two weeks, almost three times the rate of those who exercise (4-6%).