- The benefits of exercise for sleep include falling asleep faster, getting more deep sleep, and waking up less throughout the night.
- Exercise reduces stress and anxiety, increases serotonin, and helps regulate the circadian rhythm, all of which help with sleep.
- The cool down following exercise can help promote sleep, so exercise should be done three to six hours before bed.
As we begin to emerge from the Covid-19 pandemic, many people are confronting the reality of lack of exercise, weight gain, and poor sleep.
Most people are aware of how important regular exercise is to health in general and to sleep in particular. Summer has arrived and beaches and jogging trails are providing opportunities to shake off lethargy and the sedentary habits of the last year and a half. With an uptick in activity, we may soon be sleeping better. When it comes to sleep, exercise is of critical importance. We’ll now explore how exercise, and what types of exercise, have the most positive impacts on sleep.
Exercise and Its Impact on Sleep
For most of the long history of humanity, humans were quite physically active (Jacobs, 2009). This was necessary just to survive since food had to be found or grown, shelter built and maintained, and wild animals and competing groups of humans defended against. Now, consider how quickly, in just the last hundred years or so, there has been a shift for many to an essentially sedentary lifestyle. This happened with the advent of motorized vehicles, electronic communication, and the emergence of work that is more dependent on thought and creativity than physical activity. There is a disconnect between our basic bodily design and the realities of daily life in the postmodern era. Indeed, sedentary lifestyles have been implicated in increased obesity and poor health outcomes such as hypertension and diabetes.
The benefits of exercise for sleep, are well-documented and include falling asleep faster, getting a greater percentage of deep sleep, and having fewer awakenings (Epstein & Mardon, 2007). These beneficial effects of exercise seem to help older people even more than younger individuals. Insomnia, the most common sleep disorder, involves difficulty falling and staying asleep. With people of all ages, exercise is a front-line intervention. Exercise that elevates the heart rate for 20 to 30 minutes, three or more times per week, improves insomnia. Brisk walking, swimming, or similar workouts, completed several hours or more before bedtime, can make a real difference.
There are lots of ways that exercise affects sleep and life’s daily rhythms. The positive effect of exercise on sleep may be in part because it decreases stress and anxiety. Exercise clearly helps with relaxation and improves mood. It may also increase the production of serotonin, which helps with sleep. We know that it is important to cool down in order to fall asleep. We tend to turn down our thermostats on winter nights, and turn up our air conditioners on summer nights, as it is hard to sleep when it is too hot. A benefit of exercise is that after it warms us up, the following cool-down helps prepare the body for sleep. Exercise, along with light, eating, and social activity, affects the circadian clock and can help lock the circadian rhythm into a consistent 24-hour pattern. The regularity of the day/night cycle helps us be ready to sleep at bedtime.
The Psychological Benefits of Exercise
The psychological impact of physical exercise is especially important for sleep (Jacobs, 2009). It provides a healthy and safe release for anxiety and anger. Given the increase in societal stress and violence we are witnessing in the aftermath of the pandemic, it is clear that healthier ways of coping with anger are needed. Decreased anxiety is experienced within a few minutes of completing exercise and can last for hours afterward. This can offer protection against debilitating anxiety and depression. Looking better and feeling better tends to have a positive effect on self-esteem and offers protection from depression.
Belvederi et al (2019) cite an extensive literature on the best ways to use exercise in treating depression. Typically, studies have found that exercise three times per week, over a 12 to 24 week period, results in medium to large reductions in depression severity. Aerobic exercise appears to be the best form of exercise as opposed to stretching or resistance training. It is especially effective when provided as treatment in supervised group programs. There is evidence that this kind of intervention results in a 22 percent better probability of remission than standard treatment without exercise.
Exercise is also well tolerated by patients and dropout rates are low. Evidence indicates that exercise may be comparable to medication or psychotherapy. In fact, a meta-analysis of randomized clinical trials by Schuch et al (2016) showed that exercise had large effects on depression and the largest effects were for interventions that used aerobic exercise with moderate intensity when supervised by professionals.
When to Exercise to Improve Sleep
Exercise has circadian effects (Czeisler & Buxton, 2017) and this directly impacts on sleep (Jacobs, 2009). It has been shown that healthy young men who exercised for one to three hours at night had a delay in the release of nocturnal melatonin the next day, while one hour of exercise around 6:30 PM caused the release of melatonin to be moved earlier, consistent with the use of late afternoon or early evening exercise to help fall asleep earlier (see Czeisler & Buxton, 2017, p. 368).
Lack of exercise negatively impacts the daily body temperature rhythm leading to a cycle of poor sleep, low energy, and worse sleep (Jacobs, 2009). The relationship between exercise and sleep is therefore bidirectional with each influencing the other. Aerobic exercise helps with this by raising core body temperature, followed two to four hours later by the cooling that promotes sleep. Thus, the impact of exercise on sleep is best when it’s completed three to six hours before retiring. It has been found that moderate exercise, which can often be found in normal activities such as walking, biking, or washing the car may be adequate to have a positive effect.
Exercise Can Help with Conditions That Affect Sleep
Exercise can also help reduce the symptoms of restless legs syndrome (Kutscher, 2017). As anyone who has experienced the “creepy, crawly” feelings associated with restless legs can attest, it can make falling asleep extremely difficult, if not impossible. In a study reviewed by Kutscher, (2017) 12 weeks of aerobic exercise were found to significantly reduce restless legs symptoms. Likewise, research has shown that exercise has a positive effect on sleep latency (the amount of time it takes to fall asleep) and sleep efficiency (the percentage of time in bed asleep) in people with primary insomnia (insomnia that starts early in life and persists). Clearly, exercise has the potential to improve the quality and quantity of sleep and can reduce the effect of some disorders that negatively impact sleep.
Exercise is good for our mental and physical health and helps improve sleep quality. So, to make the most of this, decide to get started, choose activities you enjoy, realize that you don’t have to end a session drenched in sweat, plan a time that fits your schedule and maximizes the circadian effects, and build up slowly but steadily as your physical condition improves. Of course, if you are increasing your exercise level or have any physical health concerns, be sure to consult your physician before starting.
Belvederi Murri, M., Ekkekakis, P., Magagnoli, M., Zampogna, D., Cattedra, S., Capobianco, L., Serafini, G., Calcagno, P., Zanetidou, S., & Amore, M. (2019). Physical exercise in major depression: Reducing the mortality gap while improving clinical outcomes. Frontiers in psychiatry, 9, 762. https://doi.org/10.3389/fpsyt.2018.00762
Czeisler, C.A. & Buxton, O.M. (2017). Human circadian timing system and sleep-wake regulation, in Kryger, M.H., Roth, T., Dement, W.C. (Eds.). (2017). Principles and Practice of Sleep Medicine, 6th. Ed. St. Louis: Elsevier Saunders.
Epstein, L.J. & Mardon, S. (2007). The Harvard Medical School Guide to a Good Night’s Sleep. New York: McGraw Hill.
Jacobs, G.D. (2009). Say Good Night to Insomnia. New York: Henry Holt and Company.
Kutscher, S.J. (2017). Sleep and athletic performance, in Kryger, M.H., Roth, T., Dement, W.C. (Eds.). (2017). Principles and Practice of Sleep Medicine, 6th. Ed. St. Louis: Elsevier Saunders.
Schuch, F. B., Vancampfort, D., Richards, J., Rosenbaum, S., Ward, P. B., & Stubbs, B. (2016). Exercise as a treatment for depression: A meta-analysis adjusting for publication bias. Journal of psychiatric research, 77, 42 - 51 DOI: 10.1016/j.jpsychires.2016.02.023