Why can't I sleep after exercise?

Exercise is the best medicine - for many, that includes improving their slumber. A 2021 study showed that regular physical activity can improve sleep quality and duration. An earlier 2013 study found that adults who exercised for at least 30 minutes a day slept an average 15 minutes longer than those who were sedentary, and that moderate-intensity exercise improved sleep quality in insomnia patients.

- James Witts

Yet higher exertion levels can potentially hinder your sleep, with 2020 research suggesting there may be an intensity threshold for the sleep-promoting effects of exercise. “High-intensity exercise may elicit heightened physiological arousal and muscle soreness, counteracting the potential beneficial effects of exercise on sleep,” the study said. This is true especially if you do a hard workout late in the day.