Can You Improve Sleep By Physical Activity?

I've previously discussed the importance of sleep here and here.

Because sleep has so many advantages, it is a good idea to use a variety of sleep-improvement strategies. Judy has outlined a few strategies for a better night's sleep in a previous post here on Lifesum.

In this article, we'll look more closely at one of the strategies, regular exercise, and how it affects sleep.

The researchers conducted a meta-analysis (basically a study of many studies) to investigate the effects of various forms of physical activity (e.g., aerobic (more endurance-type exercise) or anaerobic (more strength type exercise) on various measures of sleep.

They also investigated the acute effects of exercise as well as the effects of regular exercise on sleep.

The researchers discovered that acute exercise may increase total sleep time, help you fall asleep faster (sleep onset latency), and improve sleep efficiency. Regular exercise, on the other hand, appeared to have small positive effects on sleep time and efficiency, small-to-medium positive effects on falling asleep faster, and moderate positive effects on sleep quality. Furthermore, a longer training session was linked to better outcomes (Kredlow et al., 2015). Meaning, the more you exercise, the better the effect on sleep, but there will inevitably be a point of diminishing returns, and a large enough exercise dose will almost certainly impair sleep. However, the more you exercise, the better the effect.

The authors discovered no difference in sleep quality based on exercise intensity or type (aerobic or strength) (Kredlow et al., 2015). That means you won't have to do the most strenuous exercises you can think of, and you'll be able to use whatever training method you want.

The extent to which exercise can improve sleep is unknown, but the effects appear to be minor to moderate. However, the overall beneficial effects of exercise are reason enough in my opinion to warrant daily physical activity in some form or another.

Researchers conducted a recent review of the literature on the effects of resistance exercise (strength training) on sleep. They discovered that regular resistance exercise has a positive effect on sleep, particularly self-reported sleep quality, with a minor effect on sleep duration. Interestingly, and in contrast to Kredlow et al. 2015, they discovered in this review that increased intensity of exercise had a greater beneficial effect on sleep quality than low intensity. Furthermore, the frequency of exercise may be important, with studies reporting beneficial effects with increased frequency (3 times/week).

Resistance training improved strength in addition to improving sleep quality. This is a less contentious topic, but it is a significant "side effect" of resistance training.

Furthermore, the exercise improved depression, anxiety, and stress levels (Kovacevic et al., 2017). Because mental health is essential for living a happy life, this could be one of the most beneficial health effects of exercise.

According to the review's authors (Kovacevic et al., 2017), the pharmacological treatment for sleep disturbances has only small-to-moderate effects on sleep quality, whereas resistance training has mostly moderate-to-large effects on sleep quality in the studies examined (Kovacevic et al., 2017). This, combined with the risk of side effects from hypnotic pharmaceuticals (drugs used to aid sleep) and the documented positive health effects of exercise, makes physical activity a no-brainer to incorporate into your daily routine for improved overall health and sleep.

There is no clear answer yet for the optimal intensity, frequency, and type of exercise for beneficial effects on sleep. However, a general recommendation could be to perform strength-challenging exercises at least twice a week, endurance-challenging exercises at least twice a week (at least get out of breath), and be physically active in some form every day. However, as always, the physical activity should be tailored to your specific goals and preferences.

Because sleep is such an important part of life and has so many positive health effects, both mental and physical, it is a good idea to develop habits that are both health-promoting in and of themselves and have a positive effect on sleep. One of these habits appears to be physical activity.

So, if you aren't already exercising on a regular basis, I strongly advise you to find an exercise form and regimen that you enjoy and can fit into your daily routine (or at least a few times a week).

Fredrik Wernstl is a fourth-year medical student who is interested in nutrition, training, performance, and health. His goal is to provide research-based advice to help people live healthier and happier lives.

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