Exercising in the evening does not necessarily disrupt sleep, according to experts. The effect of a late workout on sleep quality primarily depends on its intensity and an individual's fitness level.
For individuals who are less fit, it can take over an hour for their heart rate to return to a resting state after vigorous exercise, a period that can interfere with sleep. However, fitter individuals tend to recover more quickly, allowing them to fall asleep sooner. Personal preference also plays a role, with some individuals, such as night owls, finding that late workouts subjectively benefit them.
To ensure that exercise does not negatively impact sleep, experts recommend completing workouts at least four hours before bedtime. A study by Whoop indicated that workouts ending four or more hours before sleep did not disrupt sleep patterns, regardless of their duration or intensity.
Furthermore, earlier workouts may offer some sleep benefits. A 2022 study observed that a 10-minute light morning exercise session led to slightly longer sleep durations for men compared to those who did not exercise in the morning. For women, light workouts in the morning, or to a lesser extent in the afternoon, resulted in marginally more efficient sleep. Another small study from 2014 involving participants with elevated blood pressure found that cardiovascular exercise at 7 a.m. was associated with a greater reduction in nocturnal blood pressure and increased time spent in deep sleep.