Sleep is the complement to exercise. One stimulates your sympathetic nervous system, raising your heart rate, making you alert, increasing blood flow to extremities, and inducing breakdown of tissue. The other features the parasympathetic nervous system, tissue repair, a slower heart beat, and general relaxation. While not exact opposites, exercise and sleep work together to maintain optimal health.
A Guide to Sleep and Exercise
Sleep is the complement to exercise. One stimulates your sympathetic nervous system, raising your heart rate, making you alert, increasing blood flow to extremities, and inducing breakdown of tissue. The other features the parasympathetic nervous system, tissue repair, a slower heart beat, and general relaxation. While not exact opposites, exercise and sleep work together to maintain optimal health.
How Do Sleep and Exercise Work Together?
Aerobic exercise has been shown to mitigate sleep problems - from moderate reduction in quality to insomnia. When research looked at consistent aerobic exercise for at least 10 weeks, participants rated their sleep quality significantly improved. Exercise at or around 60-85% of peak heart rate for 40-60 minutes per day resulted in better scores on the gold standard of subjective sleep measurement, the Pittsburgh Sleep Quality Index (PQSI). Significant benefits across all six studies included sleep quality, latency, and less need for sleep medication.
What about weight lifting? Multiple studies have confirmed the metabolic effects of chronic resistance training on lowering resting heart rate and stress levels, which could contribute to better sleep. In a study out of the European Journal of Applied Physiology, acute effects of resistance training in the elderly showed a decrease in arousal and stage 1 sleep, meaning the research participants got to restorative sleep more quickly. The control group awoke significantly more than the resistance trainees after falling asleep as well. In short, they concluded that weight training during the day modified sleep that night, at least in the elderly.
Regular exercise absolutely has an impact on the quality of your sleep. Staying fit can make you fall asleep easier and stay asleep longer. But how does the type, time, or intensity of exercise change things?
"Exercise is really important to me - it's therapeutic. So if I'm ever feeling tense or stressed or like I'm about to have a meltdown, I'll put on my iPod and head to the gym or out on a bike ride along Lake Michigan with the girls."
- MICHELLE OBAMA
Best Exercise Habits for Sleep
Science shows that consistent fitness impacts your health in a way that enhances sleep. While one particularly hard session might make you tired, it doesn’t mean that it’s going to have long-term impacts on your sleep quality.
There are infinite ways to develop fitness, but let’s break it down in to aerobic, anaerobic, and straight power/strength. Aerobic exercise is typically longer than a few minutes with your heart rate lower than 80%. Anaerobic exercise lasts anywhere between ~10 second and three minutes, depending on your fitness and anaerobic threshold. Pure power and strength occurs in less than six seconds on average.
Being aerobically fit helps you fall asleep faster and lessens waking up during the night, according to research out of the journal Sleep. When ten habitual runners were compared to 10 non-runners, the aerobically fit runners spent significantly more hours in non-REM sleep, even when they took a day off from exercise.
What’s most interesting, though, is that modest afternoon exercise in non-runners was associated with elevated heart rate during sleep. That leaves some interesting implications for overreaching and the effects of acute, novel exercise intensity on that night’s sleep.
Exercisers in any stage of fitness should avoid overtraining. Training too hard for too long results in physiological changes that destroy sleep. For example, overtraining produces excessive epinephrine release, a cardiac stimulant that chronically raises heart rate and blood pressure. The Journal of Strength and Conditioning Research asserts that overtraining results in “increased sympathetic activity at rest”. If you’ll remember, the sympathetic nervous system runs your fight-or-flight response. Try sleeping when you’re constantly on the edge of alertness, and you’ll understand why this is an issue.
To avoid overtraining, make gradual variations in your training, including periodized increases in intensity followed by a programmed deload week. Less than 60% of your VO2 max for less than 45 minutes each day results in little to no change in cortisol, a stress hormone, so that could be a good option for most novices.
However, if you’re training for other adaptations, such as sport of fat loss, you might opt for power or high intensity aerobic training. Those exercise protocols are known to significantly increase stress and cortisol, so be sure to take necessary recovery periods. Additionally, including regular recovery protocols such as massage, hydrotherapy, and diaphragmatic breathing can bring down sleep-killing stress levels.
Best Exercise Times for Sleep
It turns out there’s a sweet spot for everyone when it comes to exercise - in accordance with your circadian rhythm. Everyone differs in morning or evening energy levels across a scale. Morning types wake and retire earlier, evening types arise and go to sleep later, and intermediates fall in the middle. Our genetics influence the speed of our internal clock and how closely our body aligns with the 24-hour cycle.
The best time to exercise for sleep is when you naturally feel the most energetic. For some, this may be earlier in the morning. For others, this could be in the evening. Both aerobic and anaerobic exercise require a significant amount of energy. Rather than force yourself to workout when you’re exhausted, utilize your natural energy levels to your advantage.
One caveat: Try to avoid working out directly before sleep, as catecholamine levels could be too high to encourage sleep onset. Let your body have a few hours to wind down for bed.
If, for some reason, you know you’re going to have a sleepless night, regular exercise could help you get through it. Sleep loss adds stress and adrenal fatigue, but research shows regular exercise can slow some of those effects.
Research investigated the effects of high intensity resistance training on the activation of the hypothalamic-pituitary-adrenal axis in rats. After a progressive resistance training program for five days per week over eight weeks, researchers kept rats awake for 96 hours. When compared to sleep deprived sedentary rats, exercise correlated with lower cortisol levels and blood pressures.
The best option for sleep is to stay consistent with your routine and exercise according to your energy levels.
Best Exercise Cadence for Sleep
Your height, weight, and stride length determine the ideal exercise cadence. Running consists of two major components - stride rate and stride length. If you want to run faster, you either increase your stride rate, which is the running cadence, or stride length, which is the distance you cover with each step.
The shorter your stride length, the faster your stride rate. For example, when running the same distance and time, a much taller person’s stride rate will be slower than someone short with a small stride length. If they both ran at the same stride rate, the taller person would likely reach the finish line quicker.
Why Does This Matter for Sleep?
The ideal exercise cadence for sleep correlates with the amount of effort you put in. Theoretically, when two people run at the same cadence, the taller person would need to run slightly longer to maintain the same level of effort. An overweight novice could top out at a slow cadence as they’re just developing fitness. There’s no universal cadence for all runners.
What you should be looking at is your heart rate. Do some experimenting with your fitness tracker to see which cadence corresponds with your ideal heart rate, and stick to that.
For increased aerobic activity to benefit slow-wave sleep, shoot for around 50-85% of your maximum heart rate, according to the American Heart Association. Higher intensities may be more appropriate for certain fitness goals. A faster exercise cadence for short, repeated bouts still improves sleep, as long as appropriate recovery is practiced.
"Reduce the stress levels in your life through relaxation techniques like meditation, deep breathing, and exercise. You'll look and feel way better for it."
- SUZANNE SOMERS
Conclusion
In order to get the most sleep-enhancing benefits of exercise, stick to these basic guidelines:
- Regular, aerobic activity 30-45 min per day for novices
- More advanced trainees should recover appropriately from high intensity anaerobic or strength training
- Exercise consistently 3-5 times per week
- Follow a progressive, periodized program with planned deloads
- Choose a workout time that aligns with your circadian rhythm
- Runners should choose their cadences in accordance with heart rate, varying intensities in a periodized way
All in all, regular exercise is fantastic for sleep. With a wide range of opportunities, your workout of choice will likely make your nights easier. If you’re having trouble sleeping, assess if you’re on an extreme end of exercise. It’s possible you need to get moving more or take a day off.
How Do Sleep and Exercise Work Together?
Aerobic exercise has been shown to mitigate sleep problems - from moderate reduction in quality to insomnia. When research looked at consistent aerobic exercise for at least 10 weeks, participants rated their sleep quality significantly improved. Exercise at or around 60-85% of peak heart rate for 40-60 minutes per day resulted in better scores on the gold standard of subjective sleep measurement, the Pittsburgh Sleep Quality Index (PQSI). Significant benefits across all six studies included sleep quality, latency, and less need for sleep medication.
What about weight lifting? Multiple studies have confirmed the metabolic effects of chronic resistance training on lowering resting heart rate and stress levels, which could contribute to better sleep. In a study out of the European Journal of Applied Physiology, acute effects of resistance training in the elderly showed a decrease in arousal and stage 1 sleep, meaning the research participants got to restorative sleep more quickly. The control group awoke significantly more than the resistance trainees after falling asleep as well. In short, they concluded that weight training during the day modified sleep that night, at least in the elderly.
Regular exercise absolutely has an impact on the quality of your sleep. Staying fit can make you fall asleep easier and stay asleep longer. But how does the type, time, or intensity of exercise change things?
"Exercise is really important to me - it's therapeutic. So if I'm ever feeling tense or stressed or like I'm about to have a meltdown, I'll put on my iPod and head to the gym or out on a bike ride along Lake Michigan with the girls."
- MICHELLE OBAMA
Best Exercise Habits for Sleep
Science shows that consistent fitness impacts your health in a way that enhances sleep. While one particularly hard session might make you tired, it doesn’t mean that it’s going to have long-term impacts on your sleep quality.
There are infinite ways to develop fitness, but let’s break it down in to aerobic, anaerobic, and straight power/strength. Aerobic exercise is typically longer than a few minutes with your heart rate lower than 80%. Anaerobic exercise lasts anywhere between ~10 second and three minutes, depending on your fitness and anaerobic threshold. Pure power and strength occurs in less than six seconds on average.
Being aerobically fit helps you fall asleep faster and lessens waking up during the night, according to research out of the journal Sleep. When ten habitual runners were compared to 10 non-runners, the aerobically fit runners spent significantly more hours in non-REM sleep, even when they took a day off from exercise.
What’s most interesting, though, is that modest afternoon exercise in non-runners was associated with elevated heart rate during sleep. That leaves some interesting implications for overreaching and the effects of acute, novel exercise intensity on that night’s sleep.
Exercisers in any stage of fitness should avoid overtraining. Training too hard for too long results in physiological changes that destroy sleep. For example, overtraining produces excessive epinephrine release, a cardiac stimulant that chronically raises heart rate and blood pressure. The Journal of Strength and Conditioning Research asserts that overtraining results in “increased sympathetic activity at rest”. If you’ll remember, the sympathetic nervous system runs your fight-or-flight response. Try sleeping when you’re constantly on the edge of alertness, and you’ll understand why this is an issue.
To avoid overtraining, make gradual variations in your training, including periodized increases in intensity followed by a programmed deload week. Less than 60% of your VO2 max for less than 45 minutes each day results in little to no change in cortisol, a stress hormone, so that could be a good option for most novices.
However, if you’re training for other adaptations, such as sport of fat loss, you might opt for power or high intensity aerobic training. Those exercise protocols are known to significantly increase stress and cortisol, so be sure to take necessary recovery periods. Additionally, including regular recovery protocols such as massage, hydrotherapy, and diaphragmatic breathing can bring down sleep-killing stress levels.
Best Exercise Times for Sleep
It turns out there’s a sweet spot for everyone when it comes to exercise - in accordance with your circadian rhythm. Everyone differs in morning or evening energy levels across a scale. Morning types wake and retire earlier, evening types arise and go to sleep later, and intermediates fall in the middle. Our genetics influence the speed of our internal clock and how closely our body aligns with the 24-hour cycle.
The best time to exercise for sleep is when you naturally feel the most energetic. For some, this may be earlier in the morning. For others, this could be in the evening. Both aerobic and anaerobic exercise require a significant amount of energy. Rather than force yourself to workout when you’re exhausted, utilize your natural energy levels to your advantage.
One caveat: Try to avoid working out directly before sleep, as catecholamine levels could be too high to encourage sleep onset. Let your body have a few hours to wind down for bed.
If, for some reason, you know you’re going to have a sleepless night, regular exercise could help you get through it. Sleep loss adds stress and adrenal fatigue, but research shows regular exercise can slow some of those effects.
Research investigated the effects of high intensity resistance training on the activation of the hypothalamic-pituitary-adrenal axis in rats. After a progressive resistance training program for five days per week over eight weeks, researchers kept rats awake for 96 hours. When compared to sleep deprived sedentary rats, exercise correlated with lower cortisol levels and blood pressures.
The best option for sleep is to stay consistent with your routine and exercise according to your energy levels.
Best Exercise Cadence for Sleep
Your height, weight, and stride length determine the ideal exercise cadence. Running consists of two major components - stride rate and stride length. If you want to run faster, you either increase your stride rate, which is the running cadence, or stride length, which is the distance you cover with each step.
The shorter your stride length, the faster your stride rate. For example, when running the same distance and time, a much taller person’s stride rate will be slower than someone short with a small stride length. If they both ran at the same stride rate, the taller person would likely reach the finish line quicker.
Why Does This Matter for Sleep?
The ideal exercise cadence for sleep correlates with the amount of effort you put in. Theoretically, when two people run at the same cadence, the taller person would need to run slightly longer to maintain the same level of effort. An overweight novice could top out at a slow cadence as they’re just developing fitness. There’s no universal cadence for all runners.
What you should be looking at is your heart rate. Do some experimenting with your fitness tracker to see which cadence corresponds with your ideal heart rate, and stick to that.
For increased aerobic activity to benefit slow-wave sleep, shoot for around 50-85% of your maximum heart rate, according to the American Heart Association. Higher intensities may be more appropriate for certain fitness goals. A faster exercise cadence for short, repeated bouts still improves sleep, as long as appropriate recovery is practiced.
"Reduce the stress levels in your life through relaxation techniques like meditation, deep breathing, and exercise. You'll look and feel way better for it."
- SUZANNE SOMERS
Rest
The bottom line is - nothing is as restorative as a consistent night’s sleep. Getting the rest both your body and mind need, however, often proves trickier than we would like. More and more of us experience sleepless nights and fatigue during the day, and modern society could be to blame.
Conclusion
In order to get the most sleep-enhancing benefits of exercise, stick to these basic guidelines:
- Regular, aerobic activity 30-45 min per day for novices
- More advanced trainees should recover appropriately from high intensity anaerobic or strength training
- Exercise consistently 3-5 times per week
- Follow a progressive, periodized program with planned deloads
- Choose a workout time that aligns with your circadian rhythm
- Runners should choose their cadences in accordance with heart rate, varying intensities in a periodized way
All in all, regular exercise is fantastic for sleep. With a wide range of opportunities, your workout of choice will likely make your nights easier. If you’re having trouble sleeping, assess if you’re on an extreme end of exercise. It’s possible you need to get moving more or take a day off.
