Burning calories is a term most often associated with aerobic exercise and physically taxing jobs. But actually, you don’t need to be engaged in strenuous activity to burn calories. Your body uses them up around the clock, even when you are asleep. Learn more about the functions your body performs at night, and exactly how it uses calories while you sleep.
Despite the fact that you are resting, your body still consumes energy when you sleep. Energy use is particularly high during REM (rapid eye movement) sleep. During this time, your brain is highly active and you burn the most glucose, your body’s source of fuel. Your heart rate and blood pressure also rise during this time, which burns more calories.
During the night, your body goes to work repairing any damage done on a cellular level during your waking hours. For instance, if you exercise during the day, your muscles will recover and repair themselves at night, which requires energy. Food digestion also uses energy, as your body breaks down your meal into usable fuel for the following day.
The amount of energy you use during sleep depends on a number of factors, including your basal metabolic rate (BMR), which determines the amount of energy your body needs to maintain its most basic functions. This includes breathing, blood circulation, and keeping your organs running. How much you weigh plays a role in setting your BMR: The more pounds you are carrying, the more energy you use. Finally, the amount of sleep a person gets influences calories burned as well. For example, a healthy person who weighs 125 pounds burns approximately 38 calories per hour of sleep, so you can multiple that number by number of sleep hours to see approximately how many calories are being burned.
Although too little sleep has been linked to weight gain, too much sleep can have a similar effect, as you are expending less energy overall during the course of the day. (You burn more calories when you are awake and moving around than when you are at rest.) In addition to getting a healthy amount of sleep, you can increase the number of daily calories burned by incorporating exercise into your routine. Focusing on eating smaller meals and avoiding alcohol before bed can also help with your metabolism.