How Much Sleep Do You Really Need?
Do you really need eight hours of sleep each night to thrive? Savvy Psychologist Dr. Jade Wu breaks down the eight-hour sleep myth and offers three ways to find the best sleep for you.
This week, let’s ask the million-dollar question: How much sleep do you really need?
We all know sleep is important. Shakespeare called it the “sore labor’s bath, balm of hurt minds, great nature’s second course, chief nourisher in life’s feast.” Less poetically, headlines these days seem to be shouting: “Sleep deprivation will make you slower and dumber!” “It will give you Alzheimer’s disease and heart attacks!” One mattress advertisement I saw simply said, “You can only live seven days without sleep.” Yikes. Talk about pressure to perform!
Fear-mongering aside, there is good evidence that sleep is important for health, well-being, and performance. A recent meta-analysis including over 1600 participants confirmed that sleep restriction is associated with poorer attention and thinking. We’ve known for decades that sleep deprivation disrupts mood. For example, it can trigger manic episodes in those with bipolar disorder. And we’re learning now, from researchers in Sweden and Germany, that insufficient sleep can even affect the microbiota in your gut.
How Much Sleep Is Enough?
But how much sleep is enough? Is there such a thing as too much sleep? If you ask Dr. Google, you’ll get over a billion answers. (That’s right; “billion” with a “b.”) The most common answer seems to be “eight hours.” That seems pretty straightforward. But where does this number come from? And if you’re thinking, “Dr. Google hasn’t examined me; how would she know how much sleep I need,” then you’re asking exactly the right question.
We’ll get to some tips and answers to the deepest sleep mysteries in a moment. But first, consider this:
We’re often told that we should drink eight glasses of water per day. (It seems like eight is a magic number). But does that apply to everyone? I’m a petite couch potato. Do I really need the same amount of water as, say, soccer phenomenon Megan Rapinoe? Does Ruth Bader Ginsberg need the same amount of water as The Rock? Actually, that’s a tough one … with the way she works out at the gym, RBG really might need that much hydration. In any case, how much water she needs to drink depends on her body’s physiology, her current activities, and other factors.
We can apply the same logic to sleep. How much sleep we need depends on how we are biologically hardwired and on our body’s current needs. The National Sleep Foundation’s 2015 guide for healthy sleep durations agrees. To come up with this guide, a panel of sleep experts used the available scientific data to determine appropriate amounts of sleep for each age group.
How much sleep we need depends on how we are biologically hardwired and on our body’s current needs.
After much rigorous work, they did not say, “You should get eight hours.” Rather, they said things like, “For teens, we recommend 8 to 10 hours, but anywhere from 7 to 11 hours may be appropriate.” Notice how there is up to a four-hour range in their recommendation—that’s a lot! Also, notice how they specified the age group they were speaking to. For newborn babies, the “may be appropriate” range is from 11 to 18 hours. For seniors over 65, that range is from five to nine hours. The take-away message is two-fold: Not only do healthy sleepers differ from each other in how much sleep they need, but healthy sleepers also change their sleep needs over time.
Now, you may be thinking, “Fair enough. I don’t expect to sleep like a baby and I’m willing to be flexible about the eight-hour rule. But how do I figure out what my own magic number is?” Worry not. This week, I will share 3 tips for figuring out the perfect amount of sleep for you, and for getting the most out of those Zzz’s.
Three Tips for Getting the Sleep You Need
1. If you’re “tired but wired,” you may be trying too hard
Have you ever said to someone, “I’m so tired I could sleep forever?” Have you dragged your exhausted body to bed only to find that your brain has flipped the “on” switch? You may toss and turn, telling your brain to shut up about tomorrow’s to-do list, and cursing it for depriving you of much-needed sleep. I call that “tired but wired.” Believe it or not, if you often feel this way, you are probably not sleep deprived. You may actually be trying too hard to get more sleep than your body needs.
You may actually be trying too hard to get more sleep than your body needs.
Hear me out, insomniacs of the world! I know it feels like the whole problem is that you don’t get enough sleep. But if you were truly sleep-deprived, you would be sleepy. And if you were sleepy, you would be able to fall asleep.
“But I do feel sleepy! I’m exhausted all day,” I hear you protest.
Let’s slow down and review. What does sleepiness feel like? Perhaps your eyelids feel heavy, and it takes effort to keep them open. Perhaps you have a hard time keeping up with the documentary you’re watching. (Wait, did the lion catch the gazelle, or … are we on penguins now?) If you’re driving sleepy, you may feel a sudden jerk when you realize that someone has pulled in front of you, seemingly out of nowhere.
On the other hand, what is tiredness, exhaustion, fatigue? Now we’re talking about sore muscles, low energy, low motivation, mental depletion … all things that make you want to curl up. But it doesn’t mean you’re sleepy. You can be “tired but wired,” as in, “I am so done with the day, but I’m wide awake.”
It’s important to know the difference between sleepiness and tiredness. Often, we think of them interchangeably and believe that we should cure tiredness by going to bed early or trying to sleep in. But trying to force sleep when your brain is not sleepy is like trying to fall in love with someone you’re just not into. It simply won’t happen. It will only cause angst and drama before you give up. So, listen to your body—if you’re sleepy, go to bed. If you’re not sleepy, enjoy your extra me time.
Listen to your body—if you’re sleepy, go to bed. If you’re not sleepy, enjoy your extra me time.
2. If you’re often sleepy during the day, you’re not getting enough nighttime sleep
This one might seem really obvious, but I think sometimes we don’t take daytime sleepiness seriously enough. After all, who hasn’t occasionally dozed off during a boring lecture or a long car ride? But if you are routinely nodding off when you don’t mean to, like during movies, when you’re sitting at red lights, or, even more problematic, while driving, then you may be excessively sleepy. There are generally three reasons for this:
- You are not getting enough sleep. This is the easiest to solve. Try setting your morning alarm for 30 minutes later, if possible, or getting into bed 30 minutes earlier. If you routinely fall asleep within a couple of minutes of lights out, keep giving yourself more time to sleep. This might require some creative problem-solving, like becoming more efficient in your morning routine, so you can buy yourself more time in bed.
- If you already get plenty of opportunities to sleep but still feel sleepy during the day, you may have a sleep-related disorder, such as sleep apnea or narcolepsy. You can try a screening tool called the Epworth Sleepiness Scale, which will ask you to rate your likelihood of falling asleep in various situations. If your score totals 10 or more, you should consult with your doctor, as these disorders can pose serious risks to your health.
- Your sleep-wake schedule is out of whack.
And that brings us to the next tip for getting enough sleep …
3. Keeping a consistent wakeup time can help
It’s not just about how much sleep you get. It’s also about when you get it, and how consistently you get it. Sleeping seven hours every night feels better than flip-flopping between four-hour nights and ten-hour nights.
Having an unstable schedule can cause daytime sleepiness one day and insomnia the next, which confuses both you and your body. Not to mention your circadian body clock gets thrown off—we’ll talk more about this important topic in future episodes. For now, just know that one of the best things you can do for your sleep and daytime functioning is to wake up at the same time every day, with one hour’s wiggle room if you really must sleep in on weekends. Don’t worry about setting a strict bedtime. Once you’ve stuck to the same wake-up time for a week or two, your body will let you know when to go to bed by making you sleepy at just the right time.
Having an unstable schedule can cause daytime sleepiness one day and insomnia the next, which confuses both you and your body.
So, here’s a recap. Getting enough sleep is important for your health and happiness. Just remember that “enough” is not the same for everyone. It’s not even the same for you throughout your life. The only way to know what your body needs is to listen to it. If you’re too sleepy during the day, then you’re not getting enough. If you struggle to fall asleep or stay asleep, you may be trying too hard. Keeping a consistent wake up time will help you to get on the same page with your body, and to have just the right amount of that sweet, innocent sleep, that balm of hurt minds and chief nourisher in life’s feast.
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About the Author
Dr. Jade Wu was the host of the Savvy Psychologist podcast between 2019 and 2021. She is a licensed clinical psychologist. She received her Ph.D. from Boston University and completed a clinical residency and fellowship at Duke University School of Medicine.
