Exercising within four hours of bedtime may affect sleep duration, timing and quality, new research published in Nature Communications suggests.
The study analysed data from an international sample of 14,689 individuals who wore a multi-sensor biometric device (WHOOP Strap) to track exercise, sleep and cardiovascular metrics. Participants were monitored over the course of a year, generating more than four million nights of data.
Engaging in strenuous workouts, including high-intensity interval training, football, rugby, or long-distance running, within four hours of bedtime was linked to delayed sleep onset, shorter sleep duration, poorer sleep quality, higher resting heart rate during the night, and lower heart rate variability.
Intense exercise raises breathing rate, core body temperature and heart rate, potentially keeping the body in a heightened state of alertness that interferes with sleep. To improve sleep, researchers recommend finishing exercise at least four hours before going to bed.
"If exercising within a four-hour window of bedtime, people could choose brief low-intensity exercises, such as a light jog or swim, to minimise sleep disruption and allow the body to wind down."
