Nighttime exercise can have health benefits, including better sleep

But neither sleep nor exercise comes in pill form. Both require time, something that is often in short supply.

The natural chronotypes of some people’s body clocks, which are what make some people night owls and others morning larks, or their work schedules allow them to go to bed early and wake up early enough to get in a workout before starting the day’s tasks. After all, exercise is often considered a great way to wake up your body and mind.

But if the easiest time for you to exercise is in the evening, you may wonder if exercise can sabotage your sleep, waking you up too much for a truly restful night and leaving you feeling more tired the next day.

Fortunately, research shows that while morning exercise is beneficial, evening exercise is also beneficial and doesn’t necessarily impair sleep.

If you have the luxury of being able to choose the time to do this, there are many reasons why you’d want to be physically active earlier in the day, says Marie-Pierre St-Onge, associate professor of nutritional medicine at Columbia University Medical Center and director from Columbia’s Center of Excellence for Sleep and Circadian Research. Morning exercises in the sun can help synchronize your body clock, making it easier to wake up in the morning and go to sleep at night. And doing a workout right off the bat saves you from skipping it later if things get busy.

But if morning workouts don’t fit your schedule, doing evening workouts might be your best bet. Any physical activity is fine, says St-Onge.

If you can carve out a little time between your workout and bed, you can reap the benefits of exercise, including better sleep, even with an overnight workout. It all boils down to biological rhythms; Everyone’s situation is different, says Michael Rogers, professor of human performance studies and director of research at the Center for Physical Activity and Aging at Wichita State University in Kansas.

Research on nighttime exercise and sleep

Exercise increases heart rate and body temperature. There’s a consensus that when these are higher, people don’t sleep as well, says Trent Yamamoto, lab coordinator at Brett Dolezals’ UC Fit Digital Exercise Physiology Research Lab. That’s why some people have the idea that they should limit nighttime activities. But, he says, whether nighttime exercise is chosen out of preference or necessity, recent studies have shown that nighttime exercise doesn’t necessarily have a negative impact on sleep. In some cases, nighttime exercise has been linked to deeper sleep at night.

And while there are some mixed results, such as a 2019 study that found higher nighttime levels of the sleep-related hormone melatonin in people who trained in the morning compared to those who trained in the afternoon, many studies show that nighttime exercise doesn’t make it worse. people’s sleep.

A 2018 review of research on nighttime exercise and sleep published in the journal Sports Medicine found, overall, that when compared to no exercise, nighttime exercise was associated with longer time in rapid eye movement sleep and in deep restorative sleep, both considered important for health. At least one review study associated a higher body temperature at bedtime with more nighttime awakenings and less efficient sleep, although the review authors note that ensuring there is at least an hour between the end of vigorous exercise and sleep should help to avoid these types of negative effects.

A small 2019 study conducted in Australia found that there were no negative effects on sleep among young men who engaged in moderate-intensity aerobic or resistance training between 8:45 pm and 9:30 pm and finished at least 90 minutes before bedtime. When they went to sleep, their body temperature had returned to baseline. Another 2020 study looking at 34 healthy men and women ages 18 to 45 who exercise regularly found no significant differences in sleep quality between morning or afternoon and evening exercisers, based on data from trackers fitness. Exercise intensity during workouts also did not affect sleep quality.

Still, experts caution that the effects of exercising at different times of the day can vary from person to person, and many of these studies are small. We need a lot more data on this, says St-Onge. Some people may find that they are more negatively affected by nighttime activities, she says, and therefore should restrict nighttime exercise more.

The best time of day to exercise?

Several studies have shown that exercising at different times of the day can have different physiological effects, says St-Onge.

A 2023 study published in the journal Nature Communications looked at more than 92,000 people in the UK and found that while any exercise was associated with a reduced risk of heart disease and cancer, people who exercised from noon to afternoon or throughout the day (as opposed to just morning or evening) had the lowest risk of cardiovascular disease.

A 2022 study published in the journal Frontiers in Physiology looked at exercise time and gender in small groups of men and women. That study found that women who trained in the morning had the greatest reductions in abdominal fat and blood pressure, while women who trained in the evening gained more strength. Men in the study who trained at night had the greatest fat burning and blood pressure benefits and felt less tired.

But while research like this can help identify some theoretical benefits of exercising at various times of the day, it shows only short-term effects in a small group of people.

For most people, the different benefits of morning or evening exercise will be so small as to not be significant, says Rogers. It’s a different story for professional athletes who work with trainers who can monitor their workouts and food intake to optimize performance, he says, but for others, getting the benefits of exercise at any time of the day will be a significant benefit to them. the health.

In general, these researchers say, nighttime exercisers should try to end the activity at least an hour or two before bedtime, to give the body time to cool down and the heart to fully recover to a resting heart rate. St-Onge says two to three hours might be best if possible. For some people, low-intensity evening exercise, such as walking or doing yoga in a darkened room, may be more beneficial, providing some of the benefits of exercise without creating too much physiological stress.

But the other key factor is knowing yourself. If someone has trouble falling asleep, I wouldn’t say it’s wise to play hoops in a well-lit gym at night, says St-Onge. But if you can run or lift weights after dinner and still fall asleep and feel rested in the morning, that’s okay, she says.

Copyright 2023, Consumer Reports Inc.

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