The whole point of beauty rest goes far beyond rest—your brain and body are seriously busy prepping for tomorrow while you snooze
We all know that sleep matters. Studies suggest that skimping on shut-eye can increase your risk of colds, make you an emotional mess (guilty!), and even up your susceptibility for serious health conditions like diabetes and heart disease. Eek.
But it's not just the rest part of a good eight hours in the sack that does your body good. While you snooze, your brain is busy, says Jessica Payne, Ph.D., an associate professor at the University of Notre Dame. What you might not realize: Some parts of your brain—especially those involved in learning and processing information and emotions—do more work while you're asleep than while you're awake (who knew?!).
Curious what else your mind and body do while you sneak in that much-deserved beauty rest? We were too.
You're Becoming More Creative
Think about everything your brain has to deal with all day long: You're "online" all of your waking hours—learning, hearing, and experiencing, says Payne. "This is all active and all incoming—you're acquiring information. You'd get really glutted if you didn't have time to go 'offline' and process that information." That's where shut-eye comes in. While you snooze, your brain goes through everything that happened in your day and figures out where to store it. This kind of processing and restructuring is important because it can lead to creative thinking and problem solving, says Payne. (Ever woken up with a solution to yesterday's work dilemma? Thank your bed.)
You're Making Memories
You may have thought that that romantic stroll with your S.O. constituted as making memories. The thing is, in order to properly remember our experiences, we have to actively commit our knowledge and experiences to memory, says Payne. All of this happens while you're passed out, so that what you learn and go through in life means something, she explains. (But put the phone down before bed! Technology Messes with Your Memory.)
You're Boosting Your Mood
Life is an emotional experience, says Payne, and "sleep is a built in emotional regulator." After all, zzz lovers and researchers alike agree that being awake all the time would (literally) be miserable. See, when you snooze, your brain fires up the regions responsible for regulating stressors and emotions—then packages and sorts through those emotions, helping you to better handle them in the future. "If you're not sleeping regularly, these emotions don't get properly organized," says Payne. "That could be why sleep and mood are so clearly linked." Plus, research shows a link between a lack of shut-eye and mood disorders, like depression.
You're Slimming Down
"It's not far off to say that you'll be fat, lazy, and stupid if you don't sleep," says Payne. And while we know shut-eye is vital for energy, our slumber directly impacts the hormones in our bodies that regulate appetite, like ghrelin—which in turn, can impact weight, she adds. Up all night? Your body treats that as a stressor, producing extra stress hormones like cortisol. And excess cortisol, Payne says, can lead to fat stores around your belly area (and belly fat is more dangerous than fat in other parts of your body). (Some people go so far as to say Sleep Is the Most Important Thing for a Better Body.)
You're Slashing Your Disease Risk
"Sleep is incredibly essential for the immune system," says Payne. Just like your brain actively helps you commit memories toward knowledge, research also suggests your immune system uses time asleep to "remember" invaders like bacteria that can lead to illness. Levels of some immune system regulators also peak during deep slumber. It's why we think some people who don't catch as many zzzs are more susceptible to colds and flus, she says.
You're Building Muscle
You know rest days matter, but if you take your workouts seriously, you should also take your evenings seriously. "Sleep is key for basic properties of healing and cellular restitution," says Payne. During deep sleep phases, your body releases human growth hormone, which helps rebuild damaged tissue and contributes to stronger muscles. Research out of Stanford also found that with five to seven weeks of 10 hours of rest a night, athletes increased their speed, accuracy, and reaction times.