It’s been proven that physical activity can make for a better night's rest. But a new study looks into how the timing of our workouts can lead to different results.
The research was carried out by sleep scientists at Canada's Concordia University, who conducted a meta-analysis of data collected across 15 studies focusing on how single intense exercise sessions affect young and middle-aged adults in the hours leading up to bedtime.
“Overall, our analysis showed that when exercise ended two hours before bedtime, there were sleep benefits, including the promotion of sleep onset and increased sleep duration,” says study leader Emmanuel Frimpong. “On the other hand, when exercise ended less than two hours before bedtime, sleep was negatively impacted. It took longer for participants to fall asleep and sleep duration decreased.”
They also found that cycling was the type of exercise that brought the most benefits in promoting sleep onset and deep sleep, and that high-intensity workouts of between 30 and 60 minutes were most beneficial for onset and sleep duration. One interesting takeaway was that high-intensity exercise, regardless of when it took place in the evening, did lead to a slight decrease in the rapid-eye-movement (REM) stage of sleep.
“Based on our review, for healthy, young and middle-aged adults with no history of sleep disorders, evening exercises should be performed in the early evening if possible,” says Frimpong. “Individuals should also keep to a consistent exercise schedule, as exercising at different times of the evening could cause sleep disturbances. Individuals should also consider whether they are morning people or evening people. High intensity exercise performed late in the evening can result in sleep disturbance for morning-type people.”
The research was published in the journal Sleep Medicine Reviews.