When you’re all revved up for the new semester, it’s easy to skip sleep in favor of studying. OK, let’s be honest—it’s easy to skip sleep in favor of Insta-scrolling, Netflix-watching, nacho-eating, and just about anything. You can technically make up a few late nights by sleeping in for a few days—but you might still be racking up serious sleep debt.
“Sleep debt is an accumulation of sleep deprivation,” says Dr. Michael Breus, a clinical psychologist and fellow of the American Academy of Sleep Medicine. Think of your sleep like a savings account, where the minimum balance has to be roughly eight hours a night (some of us might need more or less); for every night you don’t put that amount in your sleep account, you accumulate overall sleep debt. And trust us, that can add up fast. Sleep debt is pretty common—nearly 70 percent of high school students report that they snag less than eight hours a night, according to a study by the Centers for Disease Control and Prevention.
Why does it matter? Not unlike your bank account, accumulating sleep debt can leave you feeling depleted. Lack of sleep can mess with:
Academic performance: Students who are sleep deprived struggle more academically and are at a higher risk of failing compared with those who are getting enough rest on a consistent basis, says a 2014 study in Nature and Science of Sleep. “Sleep deprivation affects cognitive function directly and quickly,” says Dr. Breus.
In studies, sleep and GPA are related, but not necessarily in the ways you’d think. Consistent sleep and wake times may have more of a grade-boosting effect than logging more hours does, according to a 2014 analysis of research (Nature and Science of Sleep). It’s not just about how long you’re sleeping, but how consistent your sleep schedule is (or isn’t).
Mood: Female college students who reported nightly sleep debts of two hours or more were significantly more likely to report depressive symptoms than those with smaller debts, a 2010 study in Psychiatry Research found. What are depressive symptoms? They include everything from changes in appetite to lack of focus to a bad mood you just can’t shake. (And this is a serious thing: If you’re experiencing symptoms of depression, reach out to a friend, a trusted teacher, or a counselor at your school or in your community. Help is out there, and you matter.)
Body: Sleep debt affects your body in a number of ways: It increases the production of your hunger hormones (while suppressing the hormones that tell you you’re full), raises levels of your stress hormones, and even messes with your ability to use sugar effectively, according to a 2010 meta-analysis of studies in Pediatric Endocrinology. It can also impact athletic performance. Sleep debt ups your risk of injury on the field, according to a 2014 study published in the Journal of Pediatric Orthopedics.
Sleep debt can snowball fast. The more sleep deprived you are, the less likely you’ll be to notice it. So how do you know—and how do you fix it?
How to tell if you’re in debt
The simplest way to tell if you’re racking up sleep debt is to do the math. If the average teen needs a minimum of eight hours of sleep each night and you only get six for most days of the week, by the time Friday rolls around, you’re 10 hours in debt.
In most cases, the ideal level of sleep needed to keep your balance on track is individual, says Dr. Shelley Hershner, director of the Collegiate Sleep Disorders Center at the University of Michigan, Ann Arbor. The average person needs somewhere between seven and nine hours nightly, but “your absolute best judgment of whether you are getting enough sleep is if you can wake up at the time you’re supposed to without an alarm clock,” she says.
Here are some other signs you might be in sleep debt:
- You can’t sit through a lecture without getting drowsy or even nodding off
- You fall asleep the second your head hits the pillow
- You don’t wake up until the second your alarm goes off (during a healthy night’s sleep, you should actually go through cycles of slight wakefulness)
- You feel drowsy during downtime, such as while reading or watching TV
To figure out how much sleep you need, test your sleep limits during a break from school, when you have a solid three to four weeks to sleep as much as you want, says Dr. Hershner. “For the first week or two, you’ll probably still be catching up, but by the third week, how much you’re sleeping should be a good indication of how much your body actually needs.”
How to get out of debt
Technically, you can “pay off” your sleep debt by making up those missed hours every weekend, but playing catch-up by sleeping your weekends away isn’t ideal, partially because you’ll throw off your sleep schedule for the following week. That contributes to—you guessed it—more sleep debt. The most realistic way to get out of sleep debt is by preventing it in the first place. And the beginning of the year is the best time to do that. Here’s how:
15 minutes earlier to bed; 15 minutes later to rise
“Would I like students to get eight hours every night? Yes. Do I think that’s realistic? No,” says Dr. Hershner. If getting to bed an hour earlier every night seems about as likely as your teacher canceling a quiz in favor of a class party, try to make small schedule changes, like getting to bed 15 minutes earlier and streamlining your morning routine so you can sleep 15 minutes longer. You just clocked 30 more minutes.
Take one less social media scroll a day (Just. One.)
An easy way to score yourself those extra 15 minutes at night is to cut out one social media scroll during the day. We know tech use affects sleep, but interestingly enough, sleep also affects tech use: When you’re sleep deprived, you spend more time aimlessly scrolling on Facebook, suggests 2016 research from the University of California, Irvine. The higher your sleep balance, the more time you can bank toward an earlier bedtime.
According to Dr. Hershner, you want to try to prevent sleep debt by getting into good sleep habits—so it’s not great to fall back on the idea that you can make up all that lost sleep on the weekends. “Don’t sleep more than one to two hours longer on the weekend than you do during the week,” she says. “Say you sleep until 1 p.m. on Sunday—then it makes it hard for you to fall asleep by the time you need to get enough sleep for Monday. You’re already starting the week off behind.”
“Time management is the most important thing that helps me to prioritize my sleep,” says Susan, a junior in Kettering, Ohio. “Make yourself a bedtime. It sounds lame, but my bedtime is 9:30–10:00 p.m. at the latest.”
Keep your tech at arm’s length
The blue light emitted from your laptop or phone suppresses your levels of melatonin, a hormone that affects your circadian rhythms, says Harvard Health Publications. And that isn’t a good thing for your sleep. If you’re not going to unplug entirely, at least switch on your phone’s blue light filter and don’t hold it so close to you. “You want [your tech] as far from the face as possible,” says Dr. Hershner.
Use your computer after class and books before bed
To cut out computer usage before bed, schedule your studying so you can get any computer work out of the way earlier in the evening and switch to books in the hour before bed. “If your reading is all online, print out a few chapters to read so you can shut off the computer,” says Dr. Hershner.
Track your Zs
“I have a Fitbit that tracks my sleep, so I know how much I get,” says Brandon, a student in Los Angeles, California. “Seeing the numbers helps me.” Dr. Hershner cautions that wearable trackers aren’t always accurate, but the idea behind tracking your sleep is solid if seeing your stats motivates you to stay on track. If you don’t use a wearable, explore other options that help you feel accomplished for getting a good night’s sleep, like keeping a sleep journal or using an app. We like Sleep Cycle alarm clock, and we think you might too.
Flip your phone
Ironically enough, the more you worry about getting into sleep debt, the harder it might be for you to fall asleep. To avoid the anxiety, don’t keep a clock within view, says Dr. Hershner. Turn your alarm clock so it faces away from you and flip your phone over and put it on airplane mode when you go to sleep.
Get in a Zen zone
Meditation can be “really good for helping people transition into sleep,” says Dr. Hershner. To help you keep a consistent sleep schedule, make your bed into a relaxing sleep oasis. “Do not study on your bed. Let your bed be for sleeping only,” says Jieying, a student in Baltimore, Maryland. Close the books and download a meditation app to help quiet your mind before bed—just make sure you’re not taking the phone into your sleep zone.
Michael Breus, PhD, fellow of the American Academy of Sleep Medicine, Los Angeles, California.
Shelley Hershner, MD, director of the Collegiate Sleep Disorders Center, University of Michigan, Ann Arbor.
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