How Exercise Impacts Your Sleep

By Sarah Munn for Weight Watchers.

Why working out can help you get better ZZZs…

How Exercise Impacts Your Sleep

We all know exercise has innumerable health benefits – it can strengthen your heart, improve your flexibility and help you lose weight, to name a few, but did you know it can also help you sleep better?

“Specifically, it can improve sleep quality and help you fall asleep quicker,” says licensed psychologist Dr. Rebecca Leslie, PsyD.

“As obvious as it sounds, fatiguing yourself with physical activity enhances the chances that you’ll fall asleep more easily, and actually enjoy some good quality rest,” says Jenni Tarma, Yoga Medicine® Therapeutic Specialist and teacher on Yoga Medicine Online.

“From a nervous system perspective, the ‘feel-good’ effect of moving your body and exerting yourself a little can also help decrease feelings of anxiety, jitteriness or being wired, all of which can make it harder to fall and stay asleep,” she adds. “In other words, exercise can be a helpful way to release some of the stress of daily life, which tends to put the nervous system into a state of alertness and vigilance, and down-regulate us into a more sleep-friendly state of restful calm.”

Another possible reason that exercise can improve sleep quality has to do with body temperature.

Physical activity temporarily increases body temperature, Tarma explains, and the subsequent post-exercise temperature drop may encourage the body to wind down more easily and get ready for sleep.

How Much is Enough?

With that in mind, you may be wondering if there’s a certain amount of exercise you need to do to reap the sleep benefits.

Leslie points out that you don’t need a long-established exercise routine in order to see an effect on your sleep. “You could see an impact the same night,” she says.

And while you don’t need a routine to potentially see a difference, it can certainly help.

“The National Institutes of Health and the American Heart Association recommend about 150 minutes of exercise a week, or about 30 minutes a day for five days,” Tarma says. “Without taking into account individual variability, this is a sensible starting place which, for most people, would improve overall wellness including the ability to sleep.”

As with all general guidelines though, she says, it is helpful to figure out what is most beneficial for you and your body.

“Some folks won’t balk at a 6 p.m. HIIT [high-intensity interval training] workout and have zero trouble sleeping, while others will do better with a mellow post-dinner walk, or some gentle yoga. Studies have also shown that being consistent with your habits helps promote better quality sleep, so it’s important to find a routine that you enjoy and can stick with to really get the full benefits of your healthy exercise habits.”

And finding that routine that works for you, can be helpful in and of itself.

“Getting into a routine, i.e. exercising and going to bed at consistently similar times, can help set our circadian rhythm into a regular schedule as well,” Tarma says. “Simply put, we can use exercise to signal to the body and brain that daytime is an appropriate time to be alert and active, and subsequently nighttime is the correct time to chill out and rest.”

Does the Timing of My Workout Matter?

Every person is different, so you may find you can work out at any time of day and get to sleep just fine. But for many people, exercising close to bedtime can actually make it harder for them to fall asleep. However, it also depends on what type of exercise they’re doing – again, every person is different.

“If you are exercising in the evening and having problems sleeping, it might be helpful to think about exercising in the morning or afternoon,” Leslie says. “Some people can exercise close to bedtime without a problem, but the general guideline is to refrain from evening exercise if you have trouble with sleep.”

The exception is calm stretch workouts.

“Stretching that is calming and relaxing, and does not significantly elevate your heart rate, can be helpful before bedtime,” Leslie says. “Stretching can be something relaxing you [do] before bed to help you unwind. I would say if it is gentle stretching or yoga, this can be done close to bedtime, but anything that makes you sweat, you should stick with doing earlier in the day.”

“One study found that a moderate activity like walking helped study participants fall asleep, while running and lifting weights did not,” Tarma adds. “This suggests that activities that jack you up (i.e. up-regulate the nervous system) too close to bedtime can make it harder to fall asleep. Obviously, this will vary from one person to another, and also depend on factors like the individual’s hormonal makeup. People who have naturally elevated levels of cortisol and are in general need of nervous system down-regulation, for example, may benefit from longer bouts of strenuous exercise and find that it actually helps them to sleep better.”

It’s also worth noting, she says, that while some exercise can improve sleep quality, this is not a “more is more” situation.

“In fact,” Tarma says, “athletic overtraining can also tilt the body into a constant state of hyperarousal and cause hormonal changes that negatively impact the ability to get deep, restful sleep.”

In other words, you don’t want to overdo it.