Experts share the truth about nighttime workouts

Experts say that intense workouts at night can affect sleep quality

An evening or late-night workout could have a greater impact on your well-being than you may think.

From a run on the treadmill to 20 minutes lifting weights, you may opt for an evening session at the gym for a variety of reasons. Maybe that’s when it fits into your schedule, or perhaps an early morning workout feels like a chore.

However, health experts have warned that intense workouts before bedtime impact sleep, forcing us to reevaluate our habits.

“It really comes down to when and how hard you exercise,” Josh Leota, PhD, a sleep and circadian scientist at Monash University in Australia, told Women’s Health. “The harder you work out, the more activated your body becomes and your nervous system is in a more alert, amped up state.

“Your body will recover from that, but the key point is that the time it takes to settle back down is proportional to how hard the workout was,” he added, noting that a 30-minute jog one to two hours before bed time shouldn’t affect your sleep.

Experts say that intense exercise two hours before bedtime is linked to less sleep (Getty Images)

Still, Leota was one of the researchers behind a recent study in Nature Communications, which looked at how strenuous exercise could impact sleep.

Results found that when engaged in maximal exercise instead of light exercise two hours before bedtime, people fell asleep 36 minutes later than usual. They also slept for 22 minutes less than they usually do. As a result, the study recommended doing intense workouts, like a speed run, at least four hours before going to sleep.

A 2023 review in the journal Cureus also looked at a collection of studies about physical activity affecting the quality of sleep. The review notes that men and women spent more time sleeping when they added 10 minutes of light physical morning exercise to their daily routine.

However, for both men and women, there was a negative relationship between nighttime physical activity and sleep quality. Nighttime physical exercise, like high-intensity interval training, could negatively affect the quality of sleep if performed an hour before bedtime.

Engaging in vigorous physical exercise sessions which last more than 90 minutes in the evening is also associated with poor sleep quality, the study revealed.

Ultimately, experts recommend doing any strenuous exercise at the start of the day. Exercising early in the morning also helps to align the body’s natural rhythms with the day-night cycle.

“The reason for this is that when we wake up from a night of restful sleep, our sleep drive has been depleted and we are setting our circadian rhythm by getting good light exposure,” Dr. Andrew Colsky, sleep science expert and founder of National Sleep Center, told Real Simple.

However, if the evening is the only time to squeeze in a work out, it’s still worth doing.

“If you can exercise, do it,” Jingyi Qian, PhD, a sleep scientist at Mass General Brigham, told Women’s Health. “In general, physical activity is good for you and most of the people have too little rather than have too much, so if evening is the only time that people can find to do some exercise, I would recommend people do it.”

Leota also reiterated to the publication that regular exercise in general has many positive effects, like improving mood and sleeping better.