To burn more calories, you need to… sleep! Read this article to find out how much you burn and how to increase this number.
During the day, people consume and burn calories at different paces. It depends on body size, type of activity, exercise, genetics, and many more. But how about sleeping? Probably, you think that we don’t burn many calories when we’re asleep. It turns out the body is still at work even at night time. The amount of calories you burn by sleeping depends on metabolism, weight, and other factors.
Why Does Body Burn Calories in Sleep?
Muscles do not work much while sleeping, except when you roll over. Metabolism also gets slower, so what causes calories to burn? The answer is brain activity. When you don’t move physically, mental activity burns 20% of your resting metabolic rate. In sleep, brain activity continues. During a rapid eye movement sleep phase, your mental activity is high like you’re awake. Apart from this, many factors make you burn calories – read on to discover which ones.
Let’s Check How Many Calories You Burn
That depends. First of all, we need to know how many calories you burn during the daytime. The figures will be different for people of various activity levels, body composition, and age. To calculate the “sleep” calories, we need to do some simple math.
Know Your BMR
Basal metabolic rate, or BMR, is the number of calories that you need to keep your body alive. BMR accounts for around 80% of all daily calories. This amount includes only basic body functions, such as:
- blood circulation
- cellular repair and growth
- nerve and brain function
- control of temperature
These main body functions are also active while sleeping. They slow down in the nighttime, but they still go on, which causes calories to burn when you sleep.
BMR also depends on genetics. Everyone’s rates will be different due to:
- hormone levels
- ethnicity and race
- the ratio of muscle and fat
- physical activity
- quality and amount of sleep
- lactation and pregnancy
- general health
How to Calculate BMR
There are certain formulas to calculate BMR. They are different for men and women. The sexes have different metabolic rates not only because the bodies vary in size. Typically, men have more muscles. They burn more calories than fat, so men burn more calories.
- For men: 66 + (6.2 x weight) + (12.7 x height) – (6.76 x age) = your BMR.
- For women: 1 + (4.35 x weight) + (4.7 x height) – (4.7 x age) = your BMR.
If you don’t feel like doing math, use this online tool to calculate BMR.
Calculate Calories Burnt by Sleep
After you know your BMR, divide it into 24 to calculate calories burnt by an hour. Then, multiply your hourly BMR by 0.95. Why this number? When we’re in bed, we burn 95% fewer calories than awake.
The amount you get is the number of calories you burn hourly at nighttime. After this, multiply this figure to the number of hours you usually spend sleeping. Now, you know how much exactly calories you burn while asleep.
Average Calories Burnt By Sleeping
If you don’t want to calculate much, there are set average numbers for calories burnt by sleep. For a person who weighs 125 pounds, the calories burnt will be 38 per one hour, which means for 7-9 hours, a total number will be 266 to 342 calories.
The more the person weighs, the more calories they burn. That is true both for day and nighttime. For example, a person who weighs around 150 pounds will burn 46 calories an hour when sleeping, which totals 322-414 calories a night.
Here is the table of calories that you usually burn by sleep. The number is different depending on age, weight, and sex. The following figures are for 8 hours of sleep.
|Sex||Age||Weight||Calories burnt when sleeping|
|Female||30 y.o.||110 lbs||406 cal|
|40 y.o.||130 lbs||424 cal|
|50 y.o||110 lbs||376 cal|
|Male||30 y.o||180 lbs||601 cal|
|40 y.o.||200 lbs||619 cal|
|50 y.o.||180 lbs||558 cal|
How to Burn More Calories When Sleeping
We already know that mental activity burns the most calories during REM sleep. To get more REM sleep, follow these tips.
10 Tips to Help You Sleep
- Strictly follow your schedule – go to bed and wake up at the same time every day.
- Get the best mattress you can find. Your sleep will become deeper, better, and more comfortable.
- Exercise daily. 20 or 30 minutes of exercise a day will make you sleep more soundly. Start strength training, because it will make you gain muscles that burn more calories. Still, remember that it’s better not to exercise a few hours before going to sleep.
- Do some relaxing activities like taking a bath or doing mild yoga. But remember that these measures may work just the opposite for some people.
- Drink herbal tea or hot milk in the evening.
- Switch off your phone, computer, and all electronic devices. They may emit light that disrupts your sleeping rhythm.
- Block all distractions. Use earplugs, white noise, and blackout curtains.
- Keep your room cold.
- Try to go to bed when it’s getting dark and wake up to daylight. At night time, your body develops more melatonin which helps you sleep better. The ideal hours to go to bed are 9 or 10 pm.
- If you have trouble falling asleep, move to a chair or couch, and read a book or magazine. After some time, you will be tired enough to go to bed.
What Prevents You From Sleeping Well
If you want to burn more calories when sleeping, REM is important. Certain factors make us sleep worse, so try to avoid them.
- Don't drink coffee or strong tea in the evening – caffeine won’t let you fall asleep.
- Do not use alcohol as a sleep aid. It disrupts sleeping cycles and makes REM shorter, which means you sleep worse and burn fewer calories.
- Try not to smoke before sleep. Nicotine is a stimulant, so it will be harder to relax before sleep.
- Do not watch TV or scroll your phone or tablet. These devices emit “blue light,” which prevents us from falling asleep. This light suppresses melatonin, which is known as “sleep hormone.” This Harvard study shows that after using digital devices, people fell asleep 10 minutes longer than those who read a book.
- Limit your naps during the daytime. Anything up to 30 minutes is good, but if you nap longer, you may have trouble falling asleep.
Which Health Conditions May Affect Sleep Metabolism?
Certain health conditions can affect overall metabolism, both when sleeping and awake.
Hypothyroidism (Slow Metabolism)
When the thyroid gland can’t produce enough hormones to meet the needs of the body, metabolism changes. Thyroid hormones regulate metabolic functions. When people have hypothyroidism, they don’t have enough thyroid, and body functions slow down.
In the United States, around 4.6% of the population has hypothyroidism. If you show signs of slow metabolism, be sure to visit the doctor. Common symptoms include high cholesterol, decreased sweating, and constipation. Some other signs are dry skin, cold intolerance, weight gain, fatigue, muscle, and joint pain. In women, heavy periods or menorrhagia can be a sign of hypothyroidism.
Hyperthyroidism (High Metabolism)
Hyperthyroidism happens when the thyroid gland produces too much thyroid. This gland is in the neck and has the shape of a butterfly. Thyroid hormone controls metabolism, and when there’s too much of it, the whole body is affected. The body burns more calories when sleep, and the person often wakes up tired.
Around 1.2% of the US population has this condition. Some symptoms include oversensitivity to heat, warm damp skin, increased appetite, infertility, and hyperactivity. Also, people may have muscle weakness, diarrhea, and nervousness. Visit the doctor if you suspect increased metabolism.
People burn calories both at day and night time when they sleep. The amount of “sleep” calories is more than we may think. An adult can burn 250 to 500 calories. Still, this number heavily depends on sex, age, height, weight, and genetics. To calculate an exact number, use special formulas for BMR.
If you want to burn more calories by sleeping, try increasing the amount of rapid eye movement sleep. It burns the same amount of calories as the brain activities during the daytime. To have longer REM sleep, follow simple recommendations. Go to bed at the same time every day, don’t use digital devices, and avoid caffeinated drinks. Also, exercise every day, block distractions, and try to keep your bedroom cool.