Sleep gives your body time to recover, conserve energy, and repair and build up the muscles worked during exercise. The growth hormone produced during good quality sleep helps to promote muscle and lean tissue growth and repair.
Can exercise help you sleep?
Absolutely. And if you’ve never experienced that immediate sleep-inducing exhaustion one might experience after a day of hiking or a gruelling class, there’s scientific research to back up this claim, too.
In one study published in the journal Sleep Medicine, individuals with a self-reported sleep time of less than 6.5 hours completed moderate-intensity workouts (walking, riding a stationary bicycle, or running or walking on a treadmill) four times a week for six weeks. At the end of the experiment, they reported getting an extra 75 minutes of sleep per night — more than any drug has helped deliver, according to the study authors.
Exercise actually has a chemical effect on the brain. Physical activity creates more adenosine in the brain, and adenosine makes us feel sleepy. The harder we work out, the more driven we are by this chemical to sleep.
Does Getting Better Sleep Help My Workout?
Again, the short answer is yes. The better rested you are, the better your mind and body function — and that includes at the gym. Adequate sleep has been proved to help motivate people to stick to their exercise plans and work out the next day, according to research published in the Journal of Clinical Sleep Medicine. The more sleep time individuals in this study got, the more likely they were to complete their exercise regimen.
On the flip side, not getting enough sleep can actually make exercise feel harder, a study published in the journal Sports Medicine found. Sleep deprivation won’t affect your cardiovascular and respiratory responses to exercise, or your aerobic and anaerobic performance capability, muscle strength, nor electromechanical responses. That means biomechanically there’s no reason sleep will lessen your physical capabilities, but you will fatigue faster on less sleep, making it feel tougher to work out to your maximum capacity.
In fact, even after just one night of not sleeping, endurance performance on a treadmill decreases — likely because it feels so much tougher, reports research in the European Journal of Applied Physiology.
Better to Fit in That Early Morning Workout or Get an Extra Hour of Sleep?
Getting enough sleep and getting regular exercise are both important, so how do you decide which one takes priority? You really shouldn’t put yourself in that position, because you absolutely need both.
But if it’s not possible to find that perfect balance all the time, “I would say sleep is always the priority, unless your sleep is almost always sound in quality and quantity,” says Dr. W. Chris Winter, MD - sleep specialist and author.
So if you got seven to eight hours of sleep the night before, get up and hit the gym! But if you’ve been clocking less than six hours most nights that week, you probably want to savour that extra hour of sleep. If you skip it, chances are you’ll log a subpar workout, anyway.
And if you were up all night the night before, definitely “choose sleep!” Winter says. After an all-nighter (or just a few hours of shut-eye), your body needs the rest more than ever.
The bottom line is, if you’re not getting the recommended seven to eight hours of sleep per night, you need to rethink your schedule so you can make sure you do — and then you have to figure out how to fit in your regular workouts without sacrificing that sleep. You can’t have one without the other; both are absolutely essential to you being able to operate at 100 percent — not just in the gym, but in your everyday life, too.
To read more about this subject, we recommend both Dr Winter’s book, “The Sleep Solution: Why Your Sleep Is Broken and How To Fix It” or “Why We Sleep” by Matthew Walker. Alternatively these TED talks are enlightening:
"Why do we sleep?"
"How to succeed - get more sleep!"