Getting a full night's sleep conserves about the same amount of energy as you expend during a two-mile walk, researchers recently found. Missing out on that sleep, however, will run you down, from an energy standpoint, more than previously believed. Pulling an all-nighter burns 135 more calories than your body burns while sleeping, or roughly the energy content of that two-mile walk or a glass of milk. Wait is that all? "While the amount of energy saved during sleep may seem small, it was actually more than we expected," said Kenneth Wright and his colleagues at Colorado University's Sleep and Chronobiology Laboratory. Wright explained that many vital processes happen during sleep that burn the calories we conserve by staying still, such as learning and memory consolidation, immune function, and hormone synthesis. Wright expected these physiological processes to use almost as much energy as it takes to remain active through the night, but they do not. "The energy savings represented by sleep is physiologically meaningful," he said. In other words, sleep deprivation compounds the amount of energy that your body needs to keep running.
In Wright's seven-person study, when participants stayed awake for 24 hours, they spent 7 percent more energy, on average, than when they got eight hours of sleep.
Burning the extra calories doesn't mean that you'll lose weight , Wright warned: several studies have shown that chronic sleep deprivation is linked to impaired physical condition and weight gain. So do yourself a favor and put in a solid eight hours of shut-eye tonight.
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Natalie Wolchover was a staff writer for Live Science from 2010 to 2012 and is currently a senior physics writer and editor for Quanta Magazine. She holds a bachelor's degree in physics from Tufts University and has studied physics at the University of California, Berkeley. Along with the staff of Quanta, Wolchover won the 2022 Pulitzer Prize for explanatory writing for her work on the building of the James Webb Space Telescope. Her work has also appeared in the The Best American Science and Nature Writing and The Best Writing on Mathematics, Nature, The New Yorker and Popular Science. She was the 2016 winner of the Evert Clark/Seth Payne Award, an annual prize for young science journalists, as well as the winner of the 2017 Science Communication Award for the American Institute of Physics.