Understanding the Proven Link Between Exercise and Sleep

(i.e. how to hack your workouts for a longer, deeper night's sleep).

woman doing yoga in front of bed

Stocksy

Getting enough sleep is tricky for many people, with a reported 35.3 percent of Americans not getting the minimum of seven hours. Studies show that exercise can go a long way towards improving sleep quality (and vice versa). The exact reasons for this are relatively unknown by scientists, but sleep experts have some general ideas about why sleep and exercise go hand in hand and what to watch out for.

We interviewed holistic health expert Dr. Chad Walding, and neurologist Dr. Dean Sherzai to find out once and for all how to use exercise to your advantage when it comes to sleep.

Meet the Expert

The Link Between Exercise and Sleep 

Although the exact reasons why exercise can enhance sleep are unknown , science does show us that this is the case. For instance, moderate aerobic exercise can increase the amount of slow-wave sleep that you get each night, improve sleep quality, and reduce fatigue. And if you’re well-rested, you can get a better workout with more energy and better recovery. Sleep is when our bodies repair the oh-so-good damage we do during training sessions, creating adaptations that lead to bigger muscles, higher metabolism, and a more robust cardiovascular system.

Hormonal and mood-stabilizing effects are the most significant contributors to how sleep and exercise are positively linked, explains Sherzai: “Exercise, especially if done correctly and at the right time, can modulate one’s sleep cycles through its effect on cortisol and melatonin—increasing the cortisol and reducing melatonin in the morning.” 

“Exercise is also one of the most effective natural anxiolytics (anti-anxiety) and anti-depressants. Given that anxiety and depression are dominant contributors to sleep disorders, exercise can be considered one of the most effective sleep aids,” adds Sherzai.

But Sherzai stresses that the relationship between exercise and sleep is nuanced and says there are some dos and don’ts to be aware of:

  • Don’t ever workout without stretching, especially as one gets older, as it can lead to acute and chronic injuries, which can significantly affect the quality and depth of sleep. One of the most common reasons for poor sleep quality is aches and pains that don’t allow one to sleep, stay asleep, or get a deeper level of sleep. 
  • Try not to work out right before sleep. Though exercise may fatigue you and even help with the first phase of sleep—falling asleep—it invariably results in cramps, micro cramps, and aches and discomforts, which in turn will affect the quality of your sleep.
  • Do go for an early morning brisk walk. This helps pump up the cortisol levels, lower the melatonin levels, and increase the serotonin and dopamine levels, which help wake and move you. The natural light that your experience in the morning directly stimulates the circadian centers located behind the eyes, thus waking you up further. The morning exercise also sets the stage for a metabolically active day, resulting in better rest later in the day. 
  • Do increase your exercise routine in small increments. By slowly increasing your intensity and duration, you give your body to adjust and make it much less likely to lead to acute & chronic injury and acute and chronic pain.
  • Do balance aerobic and strengthening exercises. Both aerobic and strengthening exercises benefit sleep as they operate on different mechanisms. Whereas aerobic exercise helps with better breathing during sleep and better sleep cycles, strengthening exercises, especially over time, helps with the minor aches and pains that affect sleep quality.

Does Exercise Improve Sleep Quality?

Plenty of research has shown that exercise improves sleep quality for many reasons. “Exercise helps reduce stress and anxiety, which is one of the main reasons people can’t fall asleep. It may also reduce the risk for developing sleep disorders, such as insomnia, sleep apnea, and restless leg syndrome,” says Walding.

The best news, according to Walding: “You don’t have to spend too much time exercising daily to reap the benefits of more restful sleep, but you do have to be consistent with your exercise schedule. Even as little as 10 minutes of walking or cycling can dramatically improve sleep quality, and of course, there’s the benefit that a good workout tires you out, so the more active you are, the more likely you are to feel tired at night.” 

For a potentially more significant benefit, try to get into nature. “Exercising outside is even better because the natural sunlight helps your body regulate the sleep/wake cycle, known as your circadian rhythm,” recommends Walding.

Can Exercise Interrupt Your Sleep?

Exercise is well established as a sleep booster, but can it interrupt your sleep? “It can, especially if the exercise is too intense,” explains Walding. “If the heart rate increases too high too quickly and your body temperature increases, it’s likely to take a longer time for the body to relax,” he adds. This is due to our body’s innate sleep-signaling system that includes a natural drop in body temperature as we prepare to wind down for the night. “Our body’s core temperature naturally wants to drop when we go to sleep, so if we’re too hot, then it could interfere with that process and take longer for us to fall asleep,” says Walding. 

As well, exercising at night can be physically taxing, interrupting your level of comfort. “Late-night exercise often causes cramping and pains that affect the depth of sleep. This, in turn, leads to interrupted sleep, which has been associated with poor brain function, difficulty with attention, and short-term memory,” Sherzai explains. 

However, more gentle forms of exercise like relaxing yoga, light stretching, or a leisurely evening walk (especially around sunset) can help calm the body down to prepare for a good night's rest. 

How to Boost Sleep Quality With Exercise

Walding recommends morning and evening walks, ideally when the sun rises and just before the sun sets. “You want to expose your eyes and skin to the sun to help align your body with its natural circadian rhythms. This helps the body naturally produce cortisol (a stress hormone) in the morning and allows it to taper off in the afternoon and evening,” he explains. For this reason, it’s ideal to do your workouts outside if possible. “Again, natural sunlight helps your body regulate the sleep/wake cycle,” Walding adds. Exercising in bright daylight during the correct hours of the day and dim, low light in the evening can help regulate your body for optimal sleep.  If you find that exercise seems to interrupt your sleep quality or you have a hard time drifting off after an intense sweat session, Walding recommends adjusting when and how you workout. “The best times for intense exercise are mid-morning to mid-afternoon. Examples of intense workouts would be sprints/speedwork for runners, heavy lifting, Crossfit, HITT, or kettlebell routines. Anything in the late afternoon or evening should be more gentle, such as easy yoga, light stretching, or walking,” he says.

The Takeaway

Exercise and sleep are vital parts of a healthy lifestyle. Nailing one can provide benefits for the other and boost your performance, mood, general health, and wellbeing. Keep a record of how exercise timing affects you and whether you need to back off on the more intense exercise near bedtime. Practice recovery techniques such as yoga, stretching, or foam rolling and prioritize working out in the natural light. 

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