Do You Burn Calories When You Sleep?

Plus why a good night’s sleep is essential for supporting fitness and wellness goals.

By: Jessica Migala

Your body has a big job: And that’s to keep you alive. So, it makes sense that — yes — you do burn calories when you sleep. And, it’s pretty significant, too. Ahead, we’re covering how many calories you really burn sleeping, including some of the factors that play into just how many calories you burn while getting your beauty rest. 

RELATED: The Ultimate Guide to Sleep 

How Many Calories Do You Burn Sleeping?

Even when you’re not hoofing it on a treadmill or lifting in your living room, your body is hard at work — and that takes calories. So, it’s fair to say that you’re always burning calories, even when sleeping.

According to Harvard Health, you burn 19 to 26 calories per 30-minutes of sleeping. How much you burn depends on how much you weigh. For a 125-pound person, you burn 38 calories per half hour, a 155-pound person burns 44 calories per hour, and a 185-pound person burns 52 calories per hour. (If you weigh less than that, you’ll burn fewer calories. Weigh more? You’ll burn more.)

Burning calories while you snooze is more impactful than you might think. Research analyzed the activities (88 of them!) in a 24-hour period of 9,386 adults. Sleeping or napping, on average, accounted for 19% of one’s total energy (calorie) expenditure, per the study published in the International Journal of Behavioral Nutrition and Physical Activity in 2004.

Factors That Contribute to How Many Calories You Burn Sleeping

It’s not clear if there are any lifestyle factors that directly influence how many calories you burn while sleeping that night. This number is based on your resting, or basal, metabolic rate (BMR). Your BMR represents the energy needed to keep your body functioning properly — what you need to breathe, keep your heart beating, and repair cells, among many other roles. While your BMR is running day or night, as a whole, it accounts for about 60% of the total calories your body burns in a day.

BMR is higher the more you weigh. People with more muscle mass also have a higher BMR, as muscle is more metabolically active, so it burns more calories than fat. One of the more efficient ways to build muscle is by lifting weights and eating adequate protein. (That amount is 0.5 to 0.8 grams per pound of body weight, according to The American College of Sports Medicine (ACSM).

Another thing that can drag down BMR is dieting. When you cut calories in order to lose weight, your body conserves energy to make sure there’s enough gas in the tank to take care of organ function. (What’s more, if you lose weight, a lower body weight will also decrease BMR.) One recommendation is to moderately decrease calories while exercising in order to maintain BMR.

Sleep and Health

More important than the calories you burn when you sleep is the very real impact your nighttime sleeping habits have on your next-day metabolism and food intake. 

After a poor night’s snooze, your metabolism will be sluggish. In fact, in people who got four hours of sleep five nights in a row burned 2.6% fewer calories the next day compared to controls whose metabolism didn’t move, found a study in the journal Obesity in 2015. After being allowed to recover with a night of 12 hours of sleep, their metabolism bounced back up.

Why the dip? It’s your body’s attempt to conserve energy, say the researchers. Other research shows that if you’re short on sleep, your body needs about 100 additional calories per day, but people tend to eat 500 extra calories, per a 2013 study in Sleep. There are not only more hours available to eat in the day (and you get hungry when up and awake late), but there are also changes in hormones that control appetite that make you hungrier, suggests a study in Scientific Reports in 2017. It’s easy to see why one consequence of poor sleep is weight gain. 

Getting Enough Sleep is Key No Matter What Your Goals Are

Making sleep a priority is key for anyone for good mental and physical health. But, if your goal is to lose weight, then sleep can be a sneaky x-factor in your success. While sleeping more itself won’t increase your metabolism, getting less sleep than you need will, and that can lead to weight gain or make it more difficult for you to manage your weight.

Bottom line: Sleep — aim for at least 7 hours per night — will make achieving your goals easier. You’ll have more energy for that workout, and eating good-for-you nourishing food will come more naturally, too. No willpower required.