Exercise and sleep: does timing matter?

Exercise helps sleep a little, and for most people the time of day matters less than the old advice suggests. Reviews of the research find that evening workouts don't harm sleep overall. The one timing rule with real support is to avoid finishing a hard, vigorous session within about an hour of going to bed.

What does the research say about exercise and sleep?

The largest review is a 2015 meta-analysis in the Journal of Behavioral Medicine that pulled together 66 studies. It found that a single bout of exercise had small benefits for total sleep time, the time it took to fall asleep, sleep efficiency and deep sleep, and a moderate benefit for time spent awake during the night.

Regular exercise did a little better. It had small benefits for total sleep and sleep efficiency, small to medium benefits for falling asleep, and moderate benefits for sleep quality. The size of these effects varied with age, sex and how active people were to start with, as well as with the type, time of day and length of the exercise.

A 2015 review in Sleep Medicine Reviews reached a similar conclusion. It describes exercise as producing modest improvements in sleep for people with and without sleep complaints. The most consistent finding from exercise training studies, mostly in older adults with sleep problems, was a moderate improvement in self-rated sleep quality.

Why might exercise help you sleep?

Nobody knows for sure why exercise might help you sleep. The 2015 Sleep Medicine Reviews paper says the mechanisms are largely unknown, but that exercise may improve sleep through its effects on body temperature, arousal or adenosine levels.

Temperature may be part of why evening workouts aren't the problem many expect. The same review explains that falling asleep usually coincides with a fast drop in body temperature, and that exercise first raises core temperature and then speeds up how quickly it falls. It also points to the calming, anxiety-reducing effects of exercise as another way a later workout could help.

Does exercising in the evening hurt your sleep?

Exercising in the evening doesn't hurt sleep for most people. The traditional advice was to avoid exercise close to bedtime, and the Sleep Foundation explains why: intense exercise raises heart rate, body temperature and adrenaline. But when researchers have tested this directly, the warning hasn't held up well.

A 2019 meta-analysis in Sports Medicine looked at 23 studies comparing sleep after a single evening workout with sleep after no exercise in healthy adults. Evening exercise slightly increased deep sleep and slightly reduced the lightest stage of sleep. The authors concluded that the studies do not support the idea that evening exercise harms sleep, and if anything suggest the opposite.

The 2015 Sleep Medicine Reviews paper agreed. It concluded that the available evidence does not support the claim that late-night exercise disturbs sleep in the general population, and cited a survey of 1,000 adults in which night-time exercise was not linked to poor sleep.

When does a late workout become a problem?

The exception is hard exercise that ends very close to bed. The 2019 review found that sleep onset, total sleep time and sleep efficiency might be impaired after vigorous exercise ending an hour or less before bedtime. It also found that a higher body temperature at bedtime and a workout that was hard relative to someone's usual activity were linked to worse sleep efficiency, though these effects were less certain.

High-intensity training has its own review. A 2021 meta-analysis in Sleep Medicine Reviews looked at 15 studies of evening high-intensity exercise in healthy adults aged 18 to 50. Sessions ending 30 minutes to 4 hours before bed slightly reduced REM sleep, but nothing else changed significantly. High-intensity exercise done 2 to 4 hours before bed did not disrupt sleep, and neither did a regular evening high-intensity routine.

So a practical rule is to finish hard sessions at least an hour or two before bed. Gentler activity in the evening looks fine. The Sleep Foundation lists yoga, light stretching and breathing exercises among the types that may be most helpful for sleep.

Is there a best time of day to exercise for sleep?

The evidence doesn't point to a best time of day to exercise for sleep. The Sleep Foundation says surveys of people who exercise late at night have given mixed results and suggests basing exercise times and intensity on what suits your sleep schedule. It describes one survey in which most people who exercised at 8 p.m. or later fell asleep quickly and woke feeling rested, at similar rates to people who exercised between 4 and 8 p.m.

The 2015 Sleep Medicine Reviews paper also notes there isn't enough research yet to give specific advice on the best type, amount or timing of exercise for sleep. In practice, that leaves room to fit exercise around the rest of your day.

What if you have insomnia?

Exercise still looks useful, but the advice is more cautious. The 2015 review describes one study of adults with insomnia in which a single session of moderate aerobic exercise in the late afternoon substantially improved how quickly they fell asleep and how long they slept. High-intensity aerobic exercise and resistance training didn't change sleep in that study.

The NHS advises people with insomnia to exercise regularly during the day but not in the 4 hours before bed. If you already struggle to fall asleep, following that more conservative rule is a reasonable place to start. Pair it with the habits in how to fall asleep faster, and if trouble sleeping has lasted months, look at CBT for insomnia.

How much exercise helps?

The research doesn't give an exact dose. The 2015 Sleep Medicine Reviews paper notes that in earlier meta-analyses the largest gains in sleep time came after sessions longer than 60 minutes, while the type of exercise and people's fitness levels generally made little difference. It also cites a study in postmenopausal women in which more weekly minutes of moderate aerobic exercise brought bigger improvements in self-rated sleep quality.

The American Academy of Sleep Medicine simply includes "exercise regularly" on its list of healthy sleep habits, without setting a time of day.

Can sleep affect how much you exercise?

Sleep and exercise seem to affect each other both ways. The Sleep Foundation describes the relationship as bidirectional: exercise can improve sleep, and poor sleep is linked to lower physical activity the next day. It notes that adults with insomnia tend to be less active than those without it. That makes good sleep and regular exercise worth working on together.

If you like to train with your mouth closed, or want to know how breathing during a workout fits in, see nasal breathing during exercise.

If you want to try mouth tape and nasal strips together, our pick is the Titan Sleep System, which pairs TitanAir Nasal Strips with Titan Mouth Tape.

Read next

• Sleep hygiene: the habits with the best evidence
• Naps: how long, when, and who benefits
• Why do I wake up tired?

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.