Sleep and exercise have a mutually beneficial relationship.
Exercise, for example, tends to help you sleep better. “If you exercise at any point during the day, it’s going to improve your sleep quality,” says Keith Cushner, co-founder of Tuck Sleep, a sleep health and hygiene research company.
Research confirms this: Sleep and exercise positively affect one another, according to a 2017 review in Advances in Preventive Medicine, though researchers don’t know yet why this is the case. Plus, moderate aerobic exercise has been shown to increase the amount of deep, restorative sleep you get, according to Johns Hopkins Medicine.
“Exercise is one of those pillars of wellness, and ultimately, if you’re doing it appropriately, is going to lead to a net benefit across the board, sleep quality included,” Cushner says.
That said, the timing of your workout can make a difference, as some people can’t exercise late in the day without feeling too amped up to sleep.
Exercising too close to bedtime can make it challenging for some people to fall asleep. In particular, high-intensity exercise raises your core body temperature, speeds up heart rate, and stimulates your nervous system, all of which can lead to interrupted sleep.
A higher core body temperature, for example, signals to the body that it’s time to be awake. If you’ve ever tried to sleep in a hot environment, you’ve experienced this phenomenon in action. In fact, some types of insomnia may be related to an inability to regulate body temperature, according to a past review.
It typically takes 30–90 minutes before your core body temperature starts to fall after exercise, and that decline can help you feel sleepy, according to Johns Hopkins. However, you may find that it takes you longer to cool down after exercise.
What’s more, exercise — especially intense exercise — causes the body to release a type of hormone known as endorphins, which may keep some people awake, according to Johns Hopkins.
Late workouts don’t automatically lead to sleep troubles. For example, a 2018 review in Sports Medicine found exercising in the evening had no negative effect on sleep, though findings suggest you may want to give yourself at least one hour to wind down if you did an intense workout.
Still, some people may need a few hours to wind down, and may not be able to exercise in the evening without consequences.
Whether or not your sleep is impacted by late workouts is entirely individual, so you may need to experiment to find out how you’ll respond. Start by taking note of how you typically feel following a workout: If you tend to feel tired once you finish your workout, you may do just fine working out late in the day. However, “if you’re the kind of person that gets energized from doing workouts, then you shouldn’t work out,” Cushner says.
That said, the type of workout you do may also make a difference in how your body responds. You may be able to do low-intensity workouts, like walking, easy jogging or yoga before bed and get to sleep just fine, Cushner notes. If that’s the case, you may simply need to save the HIIT workouts for daytime hours.
If you think you can exercise intensely before bed without any negative effects, just make sure to give yourself at least an hour to relax between the end of your workout and bedtime. Cushner recommends following basic sleep hygiene principles. In other words, don’t use electronics before bed, and find an activity that relaxes you. A few great options include taking a warm shower or bath, reading a book and/or doing some light stretches. Do something that will help you transition from your workout to your bed.
Check out “Workout Routines” in the app to discover and log a wide variety of routines, or build your own routine with exercises that fit your goals.