Whether you’re getting five hours of sleep because of a busy work schedule or a teething toddler, you’re — most likely — not getting enough sleep.
You might feel fine after five hours of sleep, but really, your energy levels, health, and mental and physical performance will all take a hit.
Below, we’ll dive into whether five hours of sleep is enough (spoiler: it’s not!) and what happens when you don’t get enough sleep. Plus, we’ll share how the RISE app can calculate how much sleep you really need and make getting enough shut-eye easier.
The TL;DR: five hours of sleep isn’t enough for the vast majority of us.
Guidelines state adults need seven to nine hours of sleep. But in reality, we all have an individual amount of sleep we need a night. It’s determined by genetics — just like height and eye color — and it’s set by early adulthood.
This is most likely more than five hours, though.
When we looked at the sleep needs of 1.95 million RISE users aged 24 and older, we found:
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While there are a few lucky people out there who can survive on only five hours of sleep, these short sleepers are very — very — few and far between.
As Matthew Walker puts it in his book , “It is far, far more likely that you will be struck by lightning (the lifetime odds being 1 in 12,000) than being truly capable of surviving on insufficient sleep thanks to a rare gene.”
And even if you have one of these rare genes, you’re not guaranteed to be able to get by on a short amount of sleep. Learn more about so-called short sleep syndrome here.
“For most of the population, five hours of sleep isn’t enough," says Dr. Chester Wu. Most people need around eight hours. If you’re only getting five hours right now, try going to bed 15 minutes to 30 minutes earlier tonight and getting more sleep over the course of a couple of weeks. You might be surprised at how good you feel!”
Dr. Chester Wu who is double board certified in Psychiatry and Sleep Medicine, and provides sleep medicine services, medication management, and psychotherapy to adults at his private sleep medicine and psychiatry practice.
The recommends healthy individuals with normal sleep get:
As you can see, there’s a wide range in the recommendations for each age group. And as one states, “there is no “magic number” for the ideal duration of sleep.”
These guidelines are exactly that: guidelines. They're based on surveys that look at how much sleep people get — not what they actually need. And even that can be misleading.
Guidelines like these are often based on . And older adults may not actually need less sleep than younger adults, for example, sleep is just harder to come by. This is backed up by our RISE sleep data.
Instead of relying on vague guidelines, work out how much sleep you personally need.
You can do this by waking up without an alarm for a week or two and keeping track of how much you slept, noting when they start to regularize (known as the sleep rebound method).
Even if you have the luxury of waking up without an alarm for two weeks, this can be inaccurate for a few reasons:
RISE works as a personal sleep calculator to tell you exactly how much sleep you need in hours and minutes.
The app uses a year’s worth of phone use data and proprietary sleep-science-based models to calculate your sleep need.
You can learn more about how much sleep you need here.
RISE also tells you how much sleep debt you have. This is the amount of sleep you need to catch up on.
The higher your sleep debt, the worse you’re going to feel and function in the short term, and the worse your quality of life and overall health and well-being may be in the long run.
Try catching up on sleep to lower your sleep debt and maximize your energy, health, and productivity.
Getting five hours of sleep — or four, or six, or seven, or fewer hours than the amount of sleep you need — has negative effects the next day and in the long run.
Can you function on five hours of sleep? Just about, but you won’t be doing well.
You may have:
Heads-up: Getting five hours of sleep and topping it up with a nap? This is fine as a one-off, but it’s not recommended in the long run. Experts agree most of your sleep should happen in one continuous chunk at night for better health.
If you feel fine after five hours of sleep, that doesn’t necessarily mean five hours of sleep is enough.
One found when participants had the opportunity, they slept for an average of three hours more than usual, even though they thought they were getting enough sleep before. So they may have been sleep deprived and didn’t even know it.
Plus, suggests we are largely unaware of the increasing declines in cognitive performance we get from sleep loss.
You may also feel fine if you’re with caffeine to wake up and alcohol or sleeping pills to fall asleep.
And if you feel more alert on less sleep, you can blame a surge in the stress hormone for that (over time, high cortisol levels can lead to more sleep loss and health issues like weight gain and high blood pressure).
Even if we feel the effects of sleep deprivation, we may attribute them to other factors, like stress or health conditions, instead of the true culprit: not getting enough sleep.
We’ve covered why you feel energized on less sleep here.
Heads-up: If you’re only getting five hours of sleep, you’re probably not getting good quality sleep. You may take a while to drift off, wake up multiple times throughout the night, sleep at irregular times, and not get enough deep sleep or REM sleep for you. All this can leave you feeling tired the next day.
You can learn more about sleep quality here.
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Only getting five hours of sleep a night, even when you try for more? Here’s what could be to blame.
There’s a small chance your sleep need is five hours. If this is the case, you may find it hard to sleep for longer as your body simply doesn’t need the extra shut-eye.
As we said above, though: this is very, very rare.
Check RISE to see if your sleep need is five hours.
Heads-up: Even if you’re getting enough sleep, it’s normal to feel groggy when you first wake up and a little sleepy in the afternoon.
Sleep hygiene is the set of daily habits that influence your sleep. If you’ve got bad sleep hygiene, you may struggle to fall asleep and wake up often throughout the night. It’ll therefore be much harder to get enough sleep each night.
Poor sleep hygiene includes:
Going to bed and waking up at different times each day can throw off your circadian rhythm, which is the internal body clock that helps to control your sleep cycle.
If your sleep times are all over the place, you could find yourself only getting five hours of sleep.
This can happen if:
RISE can predict the timing of your circadian rhythm each day and show you when your body naturally wants to go to sleep and wake up. You can then see if you’re working against your body and this is causing you to sleep less than you’d like.
A sleep disorder or medical condition may be stopping you from getting enough sleep.
These include:
Speak to your healthcare provider if you think a sleep disorder or health condition is causing a lack of sleep.
Hormone changes may also be to blame for chronic sleep deprivation. You may find it harder to sleep for more than five hours when you’re on your period, pregnant, or going through menopause.
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Now you know that five hours of sleep isn’t enough for most of us, it’s time to start getting more shut-eye.
To help get more sleep, focus on your sleep hygiene. These behaviors have been scientifically proven to help you get a good night’s sleep.
Here’s what to do:
To stay on top of your sleep hygiene, RISE can tell you when to do 20+ sleep habits each day and the ideal time to do each one to make them more effective.
Five hours of sleep isn’t enough for most of us — and you can’t hack your way into getting less sleep than you need.
How much sleep is enough? That number is different for each of us.
Use the RISE app to find out how much sleep you need. Then, to help you get enough sleep, follow RISE’s personalized reminders for 20+ good sleep hygiene habits to help you fall faster and wake up less often throughout the night.
It doesn’t take long: 80% of RISE users get more sleep within five days!
For most of us, five hours of sleep is not OK. Guidelines say adults need seven to nine hours and our RISE data shows most of us need about eight hours of sleep. And while some people need five hours, it’s extremely rare. For most of us, five hours of sleep can lead to chronic sleep deprivation, low energy, poor focus, and long-term health issues.
You can survive on just a little sleep, but your energy, mood, focus, and mental and physical health will all suffer. We don’t know for sure how little sleep you can survive on. There aren’t many studies looking at sleep deprivation for longer than 72 hours as this is deemed unethical.
Studies show we can trick ourselves to feeling like we’re fine on five hours of sleep, even though objective measures of our performance and alertness show declines. Over time, chronic sleep deprivation can lead to impaired cognitive function, emotional reactivity and long-term health issues, despite subjective perceptions of adequacy. This discrepancy suggests that while people may feel they have adapted to limited sleep, their bodies and brains continue to operate at a suboptimal level.
Getting five hours of sleep once a week may be alright, if you’re otherwise getting enough sleep and catching up on lost sleep when you can, although you’ll feel tired and irritable the next day. While an occasional short night won't likely cause long-term harm if you generally maintain good sleep habits, it’s crucial not to let these nights become a frequent pattern, as the cumulative effect of sleep loss can lead to significant health and performance issues. Getting five hours of sleep once a week may be alright, if you’re otherwise getting enough sleep and catching up on lost sleep when you can. While an occasional short night won't likely cause long-term harm if you generally maintain good sleep habits, for optimum energy levels, good health, and maximum performance, you need to get enough sleep for you each night — which is most likely more than five hours.
If you need to survive on five hours of sleep, try to keep a regular sleep schedule and get more sleep from naps, if possible, to minimize the effects of the sleep deprivation. Get bright light, drink coffee (not too close to bedtime), exercise, and take a cold shower to boost your energy levels.
If you only sleep for four to five hours a night, you may have a sleep disorder like insomnia or sleep apnea. Bad sleep habits — like getting bright light, eating large meals, or drinking coffee or alcohol too late in the day — may also make it hard to fall and stay asleep.
RISE makes it easy to improve your sleep and daily energy to reach your potential
