Hitting the gym close to bedtime could be the key to a decent night of sleep, according to a new study carried out by the National Sleep Foundation.

The annual 2013 Sleep in America poll was conducted with a sample of 1,000 adults ranging in age from 23 to 60 years. The most complete data available was determined using U.S. Census data from 2010.

Physical activity was considered activity that exceeded 10 minutes in the past seven days, and participants were separated into four different levels of activity:
  • vigorous: activities which require hard physical effort like running, cycling, swimming or competitive sports.
  • moderate: activities which require more effort than normal like weight lifting, tai chi, and yoga.
  • light activity: walking.
  • no activity: those who completed no activity.

Exercisers Report Better Sleep

The poll found that exercisers documented better sleep than non-exercisers despite sleeping the same length of time every night, on average 6 hours and 51 minutes.

Light, moderate, and vigorous exercisers were more likely to say "I had a good night's sleep" almost every night or every night on work nights than non-exercisers (67% vs. 39%).

Additionally, over three-fourths of exercisers (76%-83%) said in the last two weeks that their sleep quality was very good or fairly good, compared to just over one-half of non-exercisers (56%).

Max Hirshkowitz, PhD, poll task force chair said:

"If you are inactive, adding a 10 minute walk every day could improve your likelihood of a good night's sleep. Making this small change and gradually working your way up to more intense activities like running or swimming could help you sleep better."

Hirshkowitz also pointed out that he does not think good sleep drives us to exercise, instead he believes it is exercising that improves the quality of sleep.

Vigorous Exercisers Report Good Sleep

Self-described vigorous exercisers were more likely to report "I had a good night's sleep" almost every night or every night during the working week.

Their group was least likely to document having sleep problems. Over two-thirds of vigorous exercisers say they almost never or never in the last two weeks exhibited symptoms linked to insomnia, such as waking up too early and not being able to go back to sleep (72%) or having trouble falling asleep (69%).

On the other hand, one-half (50%) of non-exercisers reported waking up during the night and close to one-fourth (24%) had trouble falling asleep every night or close to every night.

Shawn Youngstedt, PhD, poll task force member commented:

"Poor sleep might lead to negative health partly because it makes people less inclined to exercise. 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 Record the Least Amount of Sleep

Non-exercisers reported being more sleepy than exercisers. Close to one-fourth of non-exercisers (24%) define "sleepy" by a standard excessive sleepiness clinical screening measure.

This level of sleepiness happens about twice as much for non-exercisers than for exercisers.

Additionally, close to six in ten of non-exercisers (61%) report rarely or never having a good night's sleep during the work week.

Being sleepy interferes with the safety and quality of life of non-exercisers. Around one in seven non-exercisers documented having difficulty staying awake when driving, engaging in social activity, or eating, at least once in the last two weeks.

Matthew Buman, PhD, poll task force member commented:

"Sometimes we might feel tired, and that's normal, but if excessive sleepiness is your normal state, it warrants a conversation with your doctor. It could be a red flag that something is wrong with your health."

Non-exercisers also have more symptoms of sleep apnea. Sleep apnea is a major medical condition in which a person stops breathing while they are sleeping. Its symptoms include snoring, high blood pressure and tiredness.

Nearly four in ten non-exercisers (44%) had a moderate risk of sleep apnea, compared to between one in four and one in five of light exercisers (26%), moderate exercisers (22%), and vigorous exercisers (19%).

Christopher Kline, PhD, poll task force member explained, "The poll data suggest that the risk of sleep apnea in exercisers is half that of non-exercisers. People with sleep apnea are often overweight. Exercise can be part of the treatment."

Any Type of Exercise at Any Time of the Day is Good for Sleep

Apart from exercising, less time spent sitting can improve sleep quality as well as health.

People who sat for under eight hours per day reported having "very good" sleep. Also, those who spent less than 10 hours per day sitting noted excellent health, compared to those who spend 10 hours or more a day sitting (25-30% compared to 16%).

People who report exercising at night or earlier in the day showed no difference in sleep quality. Results showed that exercise at any time seemed to be better for sleep than no exercise.

Because this finding contradicts previous research tips that recommend not exercising close to bedtime, the National Sleep Foundation has changed its sleep guidelines for "normal" sleepers recommending exercise at any time, as long as it is not at the expense of sleep.

Dr. Barbara Phillips, poll task force member concludes:

"Exercise is beneficial to sleep. It's time to revise global recommendations for improving sleep and put exercise - any time - at the top of our list for healthy sleep habits."

In 2008 a study presented at SLEEP, revealed how moderate exercise can reduce anxiety and improve the sleep quality of people with insomnia.

Recommendations for a Good Night's Sleep

  • Exercise regularly. Vigorous exercise is ideal, but any exercise is better than none.
  • Create a good sleeping environment - quiet, comfortable, and cool.
  • Perform a relaxing ritual, such as a warm bath or listening to calming music.
  • Go to sleep and wake up at the same time everyday.
  • Only remain in your bed when sleeping. Try to do all other activities in other rooms.
  • Save your worries for the daytime. Realize you can't address the issues now and save them for the following day.
Written by Kelly Fitzgerald