Sleep is essential for both mental and physical health. Not getting enough sleep increases a person’s risk of developing many chronic illnesses, including cardiovascular disease, kidney dysfunction, hypertension, diabetes, stroke, obesity, and depression. More than a third of all adults living in the United States don’t get enough sleep. Findings of a recent analysis suggest that high intensity exercise does not impair sleep.

Exercise and sleep are intrinsically linked. Evidence suggests that people who exercise tend to fall asleep more quickly and have better quality sleep than non-exercisers. However, sleep experts often caution against engaging in high intensity exercise less than three hours before bedtime to prevent sleep impairment due to exercise’s effects on circadian rhythmicity as well as other effects.

The authors of the analysis reviewed data from 15 studies involving 194 healthy adult participants who engaged in high-intensity exercise before bedtime versus non-exercisers. The participants, who were between the ages of 18 and 50 years, reported regular, good sleep quality.

When exercisers completed an acute bout of high-intensity exercise one-half hour to four hours before bedtime, their rapid eye movement sleep decreased, compared with non-exercisers, but no other significant sleep changes occurred. Similarly, engaging in regular high-intensity exercise in the evening two to four hours before bedtime did not disrupt sleep.

These findings suggest that high-intensity exercise before bedtime does not impair sleep onset or quality. Many factors influence sleep onset and quality, however, including room temperature and light exposure. Learn more about these factors in this episode featuring sleep expert Dr. Matt Walker.

• Link to study abstract.