The Great Debate

Sleep vs. Exercise

What's more important: an extra hour of sleep or getting up early to work out?

The Great Debate: Sleep vs. Exercise

The sun's just coming up and my alarm goes off. I roll over and look at my sneakers—I was planning on going for a run before work—but here's the thing, I'm so freaking tired. Eyelids still heavy with sleep, I start counting the hours of sleep I got last night. Five and a half? As I let my head settle back into the comfortable groove of my pillow, I'm curious: on such groggy mornings, is it better to crawl out of bed and drag my ass to the gym, or sleep in and get some much-needed rest?

Apparently, it's not such a simple question to answer. "Exercise, sleep and nutrition form the triangle of health, and all are related," says Dr. Phyllis Zee, a professor of neurology and director of Northwestern University's Sleep Health Centers. Her research has found that a good night's sleep (logging at least seven hours of slumber) results in more productive exercise sessions later that day. Those with less sleep, not surprisingly, had reduced motivation to exercise. Likewise, "exercise can actually improve the quality of sleep," she says, leading to deep sleep that is more "restorative and effective for performance."

Bonus

A new study found that regular physical activity and a solid sleep schedule can help you hate your job less, and feel less stressed when you leave the office.

Because of this interconnected relationship, robbing yourself of either sleep or fitness seems dangerous to your overall health. But it's clear that if you're not properly rested, your workout won't be as productive. What's worse, you can even put on weight simply by sleeping less. A study published in the Journal of Applied Physiology found that chronic sleep loss results in insulin resistance and decreased glucose tolerance, making you gain more weight than someone who's fully rested. Lack of sleep is also associated with cardiac disease and increased risk of sudden death, so there's that too.

There's also some promising science suggesting that sleep can help boost your athletic performance. Consider a study done on the Stanford varsity basketball team. Players were put through a period of "extended sleep" where they were instructed to get at least 10 hours of sleep each night—significantly longer than they were used to sleeping. The result? With 10 hours a night, the team's free throw and three-point shooting percentages increased, their sprint times and reaction speeds improved and the players even reported their moods were better.

So while we all need both sleep and exercise for a healthy lifestyle, it's clear now that I should prioritize sleep over exercise—even if that means a few less gym sessions. Like most things in life, we should be shooting for quality over quantity. Because if you've slept enough, your workouts will be more effective and you'll be able to recover quicker. So now I don't feel so guilty for hitting snooze. But it's clear I've got to start going to bed earlier.

Bonus

A new study found that regular physical activity and a solid sleep schedule can help you hate your job less, and feel less stressed when you leave the office.