Many people feel that they get a better night’s sleep after a day of physical activity. It makes sense: The more active you are during the day, the easier it may be for you to relax and fall asleep at night. Interestingly enough, sleep may have as much of an effect on exercise as exercise has on sleep. Also, people who regularly sleep well may experience these effects very differently than people who have chronic sleep problems.
According to a study published in the Mental Health and Physical Activity journal, a nationally representative group of participants reported a 65% improvement in sleep quality and daytime alertness when they exercised for at least 150 minutes per week. Aerobic activities seem to be best for sleep, as they increase the levels of oxygen that reach your bloodstream. The exact reasons behind exercise helping with sleep are unknown, but there are some theories from the National Sleep Foundation. One is that your body becomes heated during a workout, and the post-workout drop in temperature may promote sleep. Another reason could be that physical activity decreases anxiety, arousal, and symptoms of depression, which may contribute toward sleep problems. By keeping active during the day, it may be easier to deal with stress, and with less stress comes a deeper and more restful sleep.
Sleep also maximizes the benefits derived from exercise. According to the Division of Sleep Medicine at Harvard Medical School, the body performs vital activities during sleep, such as providing an opportunity to recover from being used during the day. Restorative functions almost exclusively take place while asleep, such as muscle growth, protein synthesis, and tissue repair. Alternately, when humans are deprived of sleep it can cause health problems by modifying levels of hormones involved in metabolism, appetite, and stress response. If your body has not had a chance to recover and restore itself, you will not be as fit for activities the following day.
Most studies that look at the correlation between exercise and sleep do not use subjects with existing sleep issues. For people who do not have chronic sleep problems, the relationship between exercise and sleep is not as complicated. For people with insomnia, the relationship between sleep and exercise can become a vicious cycle, the lack of one hindering the other and vise versa. Insomnia can come in many different forms: difficulty falling asleep or staying asleep, waking during the night, non-restorative sleep, and daytime sleepiness.
A study published in the Journal of Clinical Sleep Medicine takes a closer look at a previous study on physical exertion and sleep. It concentrated on sedentary older women with insomnia. They were randomly directed to either remain inactive or begin doing cardiovascular exercises for 30 minutes, 3-4 times per week for 16 weeks. After the 16 weeks, the active group was sleeping much more soundly than they had been at the start of the study. They were sleeping for 45 minutes to an hour longer each night, were waking up less frequently, and were more energized during the day.
What was most interesting though, was the fact that the active participants did not experience immediate results. They did not notice an improvement in sleep the night following a day of physical exertion. In fact, they instead noticed diminished corporeal performance after a night of poor sleep. People with insomnia tend to experience extreme arousal of their stress system. Random single bursts of exercise will not help overcome this arousal, and may even aggravate it. In order to help with insomnia, an exercise routine needs to be implemented and maintained. Eventually the regular activity will start to silence a person’s stress response, and sleep will come more readily.
The process is very gradual, and does not offer immediate gratification. This makes it harder to implement into daily life, because it takes regular exercise several months to show significant and consistent changes in sleep behavior for those with insomnia. And when you are tired, it is hard to motivate yourself to be active, and your workout suffers. Once sleep and activeness become a normal routine, each will benefit the other.
As a whole, sleep and exercise are mutually beneficial, and both help maintain overall health. For people who do not experience regular problems with sleep, these benefits can be reaped almost immediately after implementing regular workouts and sleep routines. For those with insomnia or other sleep issues, it may be a bit harder to find the initial energy and endurance to begin this lifestyle change. Either way, the conclusion of these studies is that regular sleep and exercise should be incorporated into everyone’s lives, and as a pair, they can improve your health!