But neither sleep nor exercise comes in pill form. Both require time, something that’s often in short supply.
Some people’s natural body clocks — chronotypes, which are what make some people night owls and others morning larks — or their work schedules allow them to get to sleep early and wake up early enough to fit in a workout before beginning the day’s tasks. Exercise, after all, is often considered a great way to wake up the body and mind.
But if the easiest time for you to fit in a workout is in the evening, you may wonder whether exercising then might perhaps sabotage your sleep, waking you up too much to have a truly restful night and making you more tired the next day.
Fortunately, research shows that although there are benefits to morning exercise, evening exercise is beneficial, too, and it doesn’t necessarily harm your sleep.
“If you have the luxury to be able to pick your time to do this, there are many reasons 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 of Columbia’s Center of Excellence for Sleep & Circadian Research. Morning exercise in the sunlight can help synchronize your body clock, making it easier to wake up in the morning and go to sleep at night. And getting a workout done first thing prevents you from skipping it later if things get busy.
But if morning exercise doesn’t work with your schedule, getting some evening exercise may be your best bet. “Any physical activity is good,” St-Onge says.
If you are able to give yourself just a little time between your workout and bed, you can get the benefits of exercise — including better sleep — even with an evening workout. “It comes down to biological rhythms; everybody’s situation is different,” says Michael Rogers, a professor of human performance studies and the research director for the Center for Physical Activity and Aging at Wichita State University in Kansas.
Research on evening 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 of Brett Dolezal’s UC Fit Digital Health Exercise Physiology Research Laboratory. That’s why some people have the idea that they should limit evening activity. But, he says, “whether evening exercise is chosen out of preference or necessity, recent studies have shown that exercising at night doesn’t necessarily have a negative impact on sleep.” In some cases, evening exercise has been linked to more deep sleep at night.
And while there are some mixed results out there, such as one 2019 study that found higher evening levels of the sleep-related hormone melatonin in people who worked out in the morning compared with those who worked out in the afternoon, many studies do show that evening exercise doesn’t make people’s sleep worse.
One 2018 review of research on evening exercise and sleep published in the journal Sports Medicine found, overall, that when compared to no exercise, evening exercise was associated with more time in rapid eye movement sleep and in restorative deep sleep, both of which are considered important for health. At least one study in the review associated higher bedtime body temperature with more nighttime wake-ups and less efficient sleep, though the review authors note that making sure there’s at least an hour between the end of vigorous exercise and sleep should help avoid these sorts of negative effects.
A small 2019 study out of Australia found there were no negative effects on sleep among young men who engaged in moderate-intensity aerobic or resistance training between 8:45 and 9:30 p.m. and finished at least 90 minutes before bedtime. By the time they went to sleep, their body temperatures had returned to their baseline. Another 2020 study looking at 34 healthy men and women ages 18 to 45 who worked out regularly found no significant sleep quality differences between morning or afternoon and evening exercisers, based on fitness tracker data. Exercise intensity during workouts didn’t affect sleep quality, either.
Still, experts caution that the effects of exercise at different times of day may vary for different people, and many of these studies are small. “We need so much more data on this,” St-Onge says. Some people may find they are more negatively affected by evening activity, she says, and thus should restrict nighttime exercise more.
The best time of day to exercise?
Various studies have shown that exercise at different times of day may have different physiological effects, St-Onge says.
One 2023 study published in the journal Nature Communications looked at more than 92,000 people in the United Kingdom and found that while any exercise was associated with reduced risk for heart disease and cancer, people who worked out in the midday to afternoon or throughout the day (instead of just morning or evening) had the lowest risk for cardiovascular disease.
A 2022 study in the journal Frontiers in Physiology looked at exercise timing and sex in small groups of men and women. That study found that women who worked out in the morning had the greatest reductions in abdominal fat and blood pressure, while women who worked out in the evening gained the most strength. The men in the study who worked out in the evening had the greatest benefits for fat burning and blood pressure and felt less fatigued.
But while research like this can help identify some theoretical benefits to exercise at various times of day, it shows only short-term effects in a small group of people.
For most people, the different benefits of morning or evening exercise are going to be so small that they are not significant, Rogers says. It’s a different story for professional athletes working with trainers who can track their workouts and food intake to optimize performance, he says, but for others, getting the benefits of exercise at any time of day is going to be a significant benefit for health.
In general, these researchers say, evening exercisers should try to wrap up activity at least an hour or two before bedtime to give the body time to cool down and the heart time to fully recover to a resting heart rate. St-Onge says two to three hours may be better, if possible. For some people, lower-intensity evening exercise such as walking or yoga in a dim room may be most 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 difficulty falling asleep, I wouldn’t say it’s advisable to go play basketball in a bright gym at night,” St-Onge says. But if you are able to go for a run or lift weights after dinner and you can still fall asleep and feel rested in the morning, “there is no issue,” she says.
Copyright 2023, Consumer Reports Inc.
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