Yes, sleeping does burn calories. Even while you're asleep, your body continues to function, requiring energy to maintain essential bodily processes. This energy expenditure is expressed in calories burned.
How Many Calories Are Burned While Sleeping?
Multiple sources indicate you burn approximately 50 calories per hour while sleeping (Harvard Medical School, Business Insider, Sleep Foundation). This translates to roughly 400 calories per night for an eight-hour sleep. The exact number can vary depending on factors like body weight, metabolism, and sleep stages, ranging from 38 to 52 calories per hour, according to some studies (NapLab). A significant portion of calorie burning occurs during REM sleep; extending REM sleep through methods like maintaining a cooler sleep environment (around 65ºF), limiting light exposure before bed, and regular exercise, may increase calorie burn (as suggested by various sources).
Why Does Your Body Burn Calories During Sleep?
Your body uses calories even during sleep to perform vital functions, including:
- Maintaining heart rate and breathing.
- Regulating body temperature.
- Repairing and rebuilding tissues.
- Supporting brain activity.
- Continued metabolic processes.
While sleeping does burn calories, it's not an effective weight loss strategy on its own (Healthline). Weight management requires a holistic approach encompassing diet, exercise, and sufficient sleep, as a balanced approach is key for overall health. The calories burned during sleep are a part of your basal metabolic rate (BMR) - the minimum energy your body needs to function at rest (Rise Science).
The brain's energy consumption is significant, accounting for over 20% of the body's daily calorie intake, and it remains active during sleep (Live Science).
