How Much Sleep Do You Need?

The amount of sleep you require changes with age.

Posted Sep 12, 2019

We may have protested nap time when we were kids, but as adults, we know sleep is vital. (Anyone else wish they could have nap time during their day job?) Shakespeare called it the “sore labor’s bath, balm of hurt minds, great nature’s second course, chief nourisher in life’s feast.” In less poetic terms, headlines these days seem to love nothing more than to tout the downfalls of poor sleep: “Sleep deprivation will give you Alzheimer's disease and heart attacks!” One mattress advertisement I saw simply said, “You can only live seven days without sleep.” Talk about pressure to perform!

Fearful headlines aside, there is good evidence that sleep is important for health, well-being, and success. A recent meta-analysis including over 1,600 individuals supported the findings that sleep restriction is associated with poorer attention and thinking. We’ve known for years that lack of sleep 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 Many Zzz’s Is Enough?

So, how much shut-eye do you actually need? Is it possible to get too much sleep? If you ask trusty Dr. Google, you’ll get over a billion answers. The most common answer seems to be “eight hours.” Seems simple enough, right? But where does this magic 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 thinking in the right direction.

We’re often told that we should drink eight glasses of water per day. (It seems like every aspect of our health revolves around this special number.) But does that apply to everyone? If I spend most of my free time hanging on my couch scrolling through Instagram, do I really need the same amount of water as gymnast superstar Simone Biles? How much water we need to drink depends on our body’s physiology, as well as our activity level, among other factors. Shouldn’t the same logic apply to sleep?

How much sleep we need depends on how we are biologically hardwired and on our body’s needs. The National Sleep Foundation’s 2015 guide for healthy sleep durations agrees. To create the guide, a panel of experts used the available scientific data to determine appropriate amounts of sleep for a range of age groups.

After much rigorous work, they did not say, “Hey! Everyone needs eight hours, no exceptions!” Instead, they made comments like “For teens, we recommend eight to ten hours, but anywhere from seven to 11 hours may be appropriate.” Take note of the four-hour range in their recommendation—that’s a wide margin! Also, they specified the age group they were speaking to. For newborn babies, the “may be appropriate” range is from 11 to 18 hours. For adults, that number ranges from seven to nine hours and for senior citizens, that range is from five to nine hours. The takeaway here is that healthy sleep differs for different groups and sleep needs change over time. 

Now, you may not expect to sleep like a baby, but how can you determine your number? Here are three tips for figuring out your own personal sweet spot to get the most out of those precious zzz’s.

Courtesy of Shutterstock/LightField Studios
Source: Courtesy of Shutterstock/LightField Studios

Three Tips for Getting the Sleep You Need

Tip #1: If you’re “tired but wired,” you may be trying too hard.

Have you ever felt beyond ready to roll yourself into bed, just to find that, while your body was exhausted, you just couldn’t turn your brain off? You can’t stop thinking about tomorrow’s to-do list or reflecting on every embarrassing thing you’ve ever said. I call this “tired but wired.” It may be hard to believe, but if you often feel this way, you are probably not sleep deprived — you might actually be trying too hard to get more sleep than your body requires.

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 feel like I could drop,” I hear you protest.

Let’s take a minute to review what sleepiness really feels like. Perhaps your eyelids start to droop and feel weighed down. Maybe you have a hard time following along in the book you’re reading.

On the other hand, what is weariness, exhaustion, and lethargy? Now we’re talking about sore muscles, low energy, low motivation, mental depletion … all things that make you want to curl up under the covers. But it doesn’t mean you’re sleepy. You can be “tired but wired,” as in, “I am over the day, but I’m wide awake.”

We think of them as interchangeable, but there’s a difference between sleepiness and tiredness. We believe tiredness can be cured by going to bed early or attempting 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 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."

Tip #2:  If you’re often sleepy during the day, you’re not catching enough zzz’s at night.

If you are routinely nodding off when you don’t mean to, like during meetings, at concerts, or, even more problematic, while driving, then you may be excessively sleepy. There are generally several reasons for this.

You are not getting enough sleep (clearly). There are a few things you can do to remedy this. If time allows, set your morning alarm for 30 minutes later or get 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 a bit of a routine change-up, like showering at night instead of the morning, 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.

And that brings us to the next tip for getting enough sleep...

Tip #3: Keep a consistent wake-up time.

It’s not just about the hours you’re getting — it’s about how consistent those hours are. Sleeping seven hours regularly feels much 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 you and your body. 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 an hour’s wiggle room if you really must sleep in on weekends. Don’t worry about setting a strict bedtime — once you get into a regular wake up routine, your body will let you know when to go to bed by making you sleepy at just the right time.

Getting enough sleep is important for your health and happiness — but “enough” doesn’t look 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.