Why exercise helps you sleep and why sleep is good for your fitness routine

Nearly 40 per cent of adults reported getting less sleep than the required amount between 2013 and 2022, according to the U.S. Centers for Disease Control and Prevention. (Pexels/Victor Freitas)

The health benefits of a good night’s sleep have long been touted by researchers and medical professionals.

While you’re catching z’s, your body is hard at work maintaining your physical and mental health. It does so by repairing and boosting your cardiovascular and immune systems, plus regulating your metabolism. Your brain also consolidates memories and processes information from the day.

Yet while experts recommend getting at least seven hours of sleep per night, nearly 40 per cent of adults reported getting less than this required amount between 2013 and 2022, according to the US Centers for Disease Control and Prevention. That’s alarming, since sleep deficiency can lead to injuries, physical and mental health problems, less productivity, and an even greater chance of dying, according to the National Institutes of Health.

But if you’re part of that 40 per cent, there’s hope. A raft of evidence shows regular exercise helps you sleep better, and quality sleep makes it easier and more enjoyable to work out.

“The majority of people report that when they exercise, they sleep better,” said Dr. Eric Olson, president of the American Academy of Sleep Medicine and a professor at the Mayo Clinic Alix School of Medicine in Rochester, Minn. “That can mean they fall asleep more easily, enjoy deeper sleep or sleep in bed more efficiently, which means actually sleeping rather than lying awake.”

Exercising enhances sleep for a variety of reasons, according to a 2023 systematic review published in the Cureus Journal of Medical Science. Physical activity increases melatonin production, a hormone that regulates your sleep-wake cycles. It reduces stress, which often keeps people tossing and turning at night, plus boosts your mood. Finally, it helps regulate your body temperature, which is key to sleeping well.

The review concluded that regular exercise not only improves your sleep quality, but it may even help manage various sleep disorders, such as insomnia.

Exercise can definitely help combat insomnia, Olson said, along with sleep apnea. People with sleep apnea experience repeated shallow breathing during sleep, and may even stop breathing at times (If you think you might have sleep apnea, head to your medical provider right away. It can be dangerous).

“Apnea is often predicated on one’s weight,” Olson explained. “So if exercising helps with weight management, it may also reduce sleep apnea and snoring. Exercising may also help combat restless legs syndrome, another sleep disorder, where you have a compelling urge to move your legs — although some find exercise exacerbates it.”

Cooling down before bed is key

One key to using exercise to help improve the quality of your sleep is making sure your body temperature has cooled down before heading to bed. This is because a drop in core body temperature signals to your brain that it’s time to sleep. Exercising in the morning or afternoon is ideal, then, as your body has the bulk of the day to cool down.

But if evening workouts are a better fit for your schedule, it’s fine to exercise then. You just need to give yourself 60 to 90 minutes post-workout for your body temperature to lower before going to bed, said Dr. Sara E. Benjamin, medical director of the Johns Hopkins Center for Sleep and Wellness in Columbia, Md.

If you don’t have that much time to spare for an evening cooldown, skip that vigorous run and try a gentle workout instead, such as tai chi or yoga. “Yoga before bed can be relaxing, and sometimes it’s good to move around before bed so you’re not as stiff and are more comfortable sleeping,” Benjamin said.

When your sleep improves, your workouts should, too

Once your sleep improves thanks to regular physical activity, you may notice your workouts feel easier and are more enjoyable.

“When you don’t get enough quality sleep or a sufficient duration of sleep, your stamina and strength will be reduced, which can impair your workouts,” Olson said. “Also, when you’re overly tired because the quality and duration of your sleep aren’t adequate, it will be harder to get motivated to work out.”

To further the symbiotic relationship between exercise and sleep, consider exercising outdoors rather than at the gym. “Being outside and having natural light exposure is helpful,” Benjamin said.

That’s because exposure to natural light is imperative to the operation of your body’s circadian rhythm, or internal clock. Your circadian rhythm is a 24-hour cycle that regulates a variety of physiological processes in your body. It’s primarily influenced by light and darkness, which cue your body that it’s time to wake up or prepare for bed.

Yet the link between good sleep and exercising at times is a personal one. Some people will be able to fall asleep even if they exercise right before bed or ingest caffeine, for example. And younger people may find exercise more beneficial to quality sleep than older adults, who tend to have sleep issues.

Still, some form of exercise should help most people improve their sleep. And a good night’s sleep should make your workouts — and pretty much everything else in your life — more enjoyable.

Melanie Radzicki McManus is a freelance writer for CNN who specializes in hiking, travel and fitness.