HIIT workouts right before bed might be sabotaging your sleep, here's why

Exercise is often associated with helping you to sleep but new research shows intense workouts before bedtime using the best online personal trainer and fitness apps may not be the key to a good night’s rest.

A new meta-analysis by researchers at Concordia University, published in the journal Sleep Medicine Reviews, assessed data from 15 published studies to see how a single session of intense exercise affects young and middle-aged healthy adults in the hours before bedtime.

And while no two people are the same, the researchers did find that a combination of factors can enhance or lessen the effects of exercise on sleep.

Exercise and sleep: what the studies showed

The researchers ran a statistical analysis that examined variables such as the timing of exercise - early evening or late evening - and the hours between finishing exercise and bedtime - less than two hours, around two hours, and two to four hours.

Other variables included the participants’ fitness level (sedentary or physically active) and the intensity and duration of the exercises. They also analyzed how specific types of exercise influence sleep.

“Overall, our analysis showed that when the exercise ended two hours before bedtime, there were sleep benefits, including the promotion of sleep onset and increased sleep duration,” says the study’s lead author 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.”

“Based on our review, for healthy adults with no history of sleep disorders, evening exercises should be performed in the early evening, if possible,” concludes Frimpong.

Further analysis showed that working out for between 30 and 60 minutes improved sleep onset and duration and cycling on the best exercise bikes was found to benefit participants most in terms of onset and deep sleep.

When choosing when to work out, you also need to consider whether you are a morning or evening person. For example, the researchers noted that performing a HIIT workout right before bed might lead to sleep disturbance for morning-type people.

If you’ve found yourself struggling to sleep after an intense workout, push your workout time to around two hours before bedtime to see if that helps.