Not to sound like a parent calling to check in, but — are you getting enough sleep?
It’s a question many of us ask ourselves after a few days of late-night Netflix or staying up to cram for exams. Everyone goes through periods of poor sleep, but your regular habits around bedtime do have a significant effect on your long-term health, according to numerous studies.
So how long does a person need to sleep at night to feel rested? We asked scientists, who break it down below.
Research provides some guidelines on when and how long you should sleep each night — and how to make getting enough hours a steady habit.
How long should you sleep each night?
Is there really a magic number? During two-year study, researchers from the National Sleep Foundation discovered that most adults need between seven and nine hours of sleep each night.
Some people’s sleep durations will vary slightly from the recommendation — think of that friend who seems to be always awake yet seems to function just fine. Some rare genetic conditions do make it possible for you to thrive on less sleep, maybe just six hours, as neuroscientist Chelsie Rohrscheib tells Inverse.
In general, it’s unusual for someone to deviate significantly from the recommendation for their age range, the study authors say. Sleeping more, or less, could be a sign of a more serious health problem.
Hypersomnia, or consistent oversleeping, can be a sign of other problems, for instance. People with Seasonal Affective Disorder often report hypersomnia and insomnia, or being unable to fall asleep, as Inverse has reported.
With sleep being linked to depression, it’s a good idea to keep track of your sleep and check in with what it might mean for your mental health.
As our bodies age, the amount of sleep we need changes — so the recommendations vary across a person’s lifetime:
Newborns: 14 to 17 hours
Infants: 12 to 15 hours
Toddlers: 11 to 14 hours
Preschoolers: 10 to 13 hours
Elementary schoolers: 9 to 11 hours
Teenagers: 8 to 10 hours
Young adults to adults: 7 to 9 hours
Older adults: 7 to 8 hours
Tracking sleep accurately
Ironically, parents of young, sleep-needing children rarely get enough hours themselves — and they’re well aware of it. For many of us, though, our perception about how much we sleep might be way off.
A study published in Nature in October 2019 found that people’s self-reported sleep amounts turned out to be pretty different from the numbers shown on their wearable trackers, like FitBits. On average, study participants slept for 6 hours and 28 minutes each night, missing the mark for the proper amount of rest.
“Sleep questionnaires tend to be unreliable and biased because people tend to not do a good job at estimating the amount of sleep they’re getting,” study author Weng Khong Lim told Inverse at the time. “Those who sleep between say five to eight hours per night tend to just report a number that is close to the recommended number of hours per night, for example, seven.”
Does bedtime make a difference?
Getting to bed at a reasonable hour can be the deciding factor for the rest of your night’s rest. So, does your bedtime matter? You may have even heard the myth that the hours of sleep you get before midnight count double. (A former running coach of mine used to say the worth was 1.5 times your post-midnight sleep.) That may be a bit arbitrary, but when you get sleep can still have an impact on how rested you feel.
A February 2019 study showed that the idea of trying to “catch up” on sleep over the weekend is yet another myth. Addressing sleep debt has to come from consistently catching enough Z’s, as Inverse has reported. Even if you sleep your Saturday and Sunday away, if you then turn back to sleep-depriving habits during the week, you won’t strike a balance.
What’s more, getting just five hours of sleep each night is linked to health consequences — late-night snacking, weight gain, delayed release of melatonin, and even reduced sensitivity to insulin, the study found.
You’re best off getting the rest you need by forming habits that keep you regularly hitting your sleep targets. Your body will thank you for it.