Study Finds ‘Late-Night Exercise’ Impacts Sleep and Heart Health

Sydney – A new study from Monash University in Australia has revealed that engaging in vigorous exercise within four hours before bedtime may negatively affect sleep quality and heart health. This is due to delayed sleep onset, increased nighttime heart rate, and reduced heart rate variability (HRV).

The study tracked 14,689 people around the world who used the WHOOP Strap, a wearable fitness tracker, over the course of one year. It collected data from over 4 million nights and was published in the journal Nature Communications on Wednesday (April 16).

Josh Leota from the university’s Department of Psychology and the lead author of the study explained that intense evening exercise can leave the body in a heightened state of alertness, which may interfere with the body's ability to relax and fall asleep.

High-intensity exercises such as HIIT (high-intensity interval training), playing football, or long-distance running were found to have the greatest impact on sleep—regardless of factors such as age, sex, fitness level, or previous night's sleep quality.

The researchers recommend avoiding vigorous exercise within four hours of bedtime. Instead, they suggest opting for lighter activities such as jogging or slow swimming to minimize sleep disruption.