Sometimes, later in the evening seems to be the only or the best time to work out. Maybe the daytime tangled you up with responsibilities, and now it’s dark outside, and instead of putting on your pajamas, you’re lacing up your sneakers. As the old adage goes, ‘Any exercise is better than no exercise,’ and getting your muscles moving provides numerous health benefits, from lowering your blood pressure to boosting your mood and cardiovascular fitness.
However, some question whether working out too close to bedtime negatively affects sleep quality. Could there be a downside to getting your fitness in and those endorphins flowing later in the day? Researchers set out to explore these questions in a recent study.
The study
In a meta-analysis published in the journal of Sleep Medicine Reviews, the researchers analyzed how nighttime exercise impacts sleep quality. They assessed existing research on high-intensity exercise before bedtime and its effects on sleep throughout the night. 15 studies and 194 healthy adult participants with no sleep difficulties were included in the meta-analysis.
The researchers wanted to understand how the type, timing, and duration of exercise, and how individuals’ sleep chronotypes and fitness levels affected their sleep.
The results
The meta-analysis concluded that exercising at night didn’t disrupt nighttime sleep for most people until they reached a certain window. Lead researcher Emmanuel Frimpong said, “When the exercise ended less than two hours before bedtime, sleep was negatively impacted.” It also took participants longer to fall asleep and decreased sleeping duration.
Exercising in the window two to four hours before bed didn’t interfere with sleep and showed benefits, such as promoting the onset of sleep and increased sleep duration. That being said, participants who exercised two to four hours before bedtime had less time in the REM sleep stage compared to the no-exercise control group. REM refers to the rapid eye movement or dream stage of sleep characterized by relaxed muscles, increased brain activity, and elevated heart rate.
The takeaway
The takeaway is that exercising in the early evening still promotes health benefits and doesn’t interfere with your sleep. More research is needed, but high-intensity exercise that ends less than two hours before bedtime could be detrimental to your sleep.
It’s important to keep in mind that this research was performed with high-intensity exercise rather than lower-intensity exercises like various types of yoga. Different types and intensities of exercise might have different effects on your snoozing. In the studies examined, the researchers concluded that cycling was the best choice for supporting deeper sleep. The night owls seemed to get more benefit from evening workouts compared to the early birds, so if you’re more of a ‘morning person’, exercising earlier in the day might be the better choice.
If the evening is the only time you can fit working out into your schedule, it’s worth making the effort to enhance your overall health and fitness, but you might decide to do it prior to that two-hour window before bedtime. It’s also possible the release of endorphins that comes along with exercise could promote a more stress-free slumber.
