Is It Better to Sleep In or Work Out?

person in bed hitting alarm clock early in the morning
person in bed hitting alarm clock early in the morning

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Staying healthy is so easy, right? Log eight hours of sleep, work out for an hour a day at least five days a week, and steer clear of processed foods. Also drink enough water, meal prep, and meditate. Trying to fit it all in, on top of all the other variables in your life (kids! work! relationships!), can seem impossible. So when you're debating the choice of lying in bed for another two hours or schlepping to the gym, sometimes shuteye wins. We get it: working out with no sleep can be a real drag.

But is that such a bad thing? After all, some mornings you just don't feel well, or maybe you overdid it yesterday. Is it ever worth it to sleep in and skip the gym? Turns out, science still doesn't have the hard and fast answer (yet).

"Both sleep and exercise are main behaviors that contribute to physical and mental health," says Kelly Glazer Baron, Ph.D., a clinical psychologist and an associate professor at the University of Utah. Her research, published in the Journal of Clinical Sleep Medicine, has found that clocking at least seven hours of sleep can actually help you work out longer and harder the next day. And the exercise/sleep equation goes both ways — people with insomnia who started a regular aerobic exercise program improved the quality of their sleep and felt less tired during the day, another study from Northwestern University found. So working out on no sleep can actually help with the whole "no sleep" thing!

Considering multiple studies point to the direct relationship between sleep and exercise, there's no denying that you should strive for adequate amounts of both, adds Shannon Fable, director of partnerships at Stronger U Nutrition and a health and fitness expert for the American Council on Exercise. "If that's impossible, try to only sacrifice your sleep two to three days during the week in order to hit the early morning cycling class. Get some extra sleep the other days and on the weekends."

That said, there are still a few hard and fast rules you can follow to determine what to do on those tough days when your bed feels oh-so-comfy.

Sleep or Sweat?

If you got seven to eight hours of sleep the night before... You're good to hit the gym, says Fable. Seven to nine hours of sleep is what most adults need, according to the National Sleep Foundation.

If you've been sleeping less than six hours most nights that week... It's time to rethink your schedule, recommends Baron. See where you can cut corners to be more efficient: Head to bed 15 minutes earlier or shave 10 minutes off your morning routine to get a bit more sleep. If you're not a morning person, consider a lunch break or an after-work gym time. (Try these insanely effective short workouts when you're crunched for time.)

If you were up all night... Definitely skip the a.m. sweat sesh, Fable says. (And maybe stock up on some possible sleep aids.) Not only do you need sleep, but your coordination will be affected, making exercise potentially more dangerous. Your ratings of perceived exertion will also make exercise feel harder than it is, she warns. Even if you're working out at the same intensity as you usually do, sleep deprivation can mess with your mental performance, according to research published in the journal Advances in Preventive Medicine. Moderation is key when working out on no sleep or when tired. Exercising too hard can make you more tired and increase your risk of injury because fatigue can hamper concentration and form. "When you're feeling sleepy, back off a little from your workout status quo; reduce the intensity and duration of your exercise," says Shawn Youngstedt, Ph.D., a professor at the Arizona State University College of Nursing & Health Innovation.

If you've only worked out once that week (and it's Friday)... If you're aiming for three to four workouts per week, it's time to move, says Baron. Just 150 minutes of moderate to vigorous exercise during the week can lower your risk for heart attack and stroke, says the American Heart Association. So don't hit snooze!

If you've been consistently killing it at the gym that week... Skip your workout, advises Fable. Everyone deserves a day off and your body needs sleep to repair after heavy workouts. Rest days allow for protein synthesis, which is crucial for building muscle, according to a study in the Journal of Strength and Conditioning Research.

If you're sore... Sleep in and take a day off. Overtraining can cause a decrease in sleep quality and duration, Baron says.

If You're Feeling Beat...Eat for All-Day Energy

After a rough night, whether you're working out with no sleep or heading straight to work, skip the energy drink in favor of revitalizing nutrients. "It's amazing how eating the right foods can help you make it through the day," says Lauren Antonucci, M.S., R.D., the founding director of Nutrition Energy, a private nutrition-counseling service in New York City.

Antonucci's meal plan will keep you revved — and full — until dinner.

  • When you wake up: Dehydration compounds fatigue, so down two glasses of water first thing. Aim to sip half your body weight in fluid ounces by bedtime (for a 145-pound woman, that's 72 1/2 ounces, or about nine cups).

  • Breakfast: Go for eggs, scrambled or hard-boiled. "They're one of the most absorbable types of protein, with just the right amount of fats and a dose of energy-boosting B vitamins," Antonucci says. For staying power, add healthy carbs, like a slice of whole-grain toast and some fruit. A hit of caffeine will kick-start your day; if java makes you jittery, grab a mug of green tea. It has some caffeine, plus a compound called epigallocatechin, which, studies show, produces a relaxed and attentive state.

  • Midmorning: Improve your focus with a handful of mixed nuts, such as almonds, walnuts, and peanuts. The protein provides a jolt of energy, while the combo of filling fiber and omega-3 fatty acids tides you over until lunch.

  • Lunch: Build your meal out of lean protein, slow-burning complex carbs, and healthy fats — try a skinless chicken breast with a broccoli, black bean, and quinoa salad — to power through the next few hours.

  • Late afternoon: Chips or chocolate chip cookies may sound awfully good right about now, but after causing a quick spike in your energy level, they will send it crashing. For a steady, long-lasting pick-me-up, choose nutrient-rich high-fiber snacks like hummus with a whole-grain pita or baby carrots.