10 Myths About Sleep

by Maria Trimarchi»

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Getting More Sleep Image Gallery

Incorrect beliefs about the science of sleep could be keeping

you from getting the best and most beneficial rest.

Rip van Winkle was an idle man, who, as the story goes, took a

walk in the woods to catch a break from his wife, drank a

stranger's brew and proceeded to fall asleep for 20 years. You,

however, can't sleep for 20 years (no matter what you may be

trying to escape). Nor can you go without. Not only does a lack

of sleep kill your brain cells, it could also eventually kill you.

But what of the more subtle aspects of sleep science? For

example, did you know that you yawn less when you're cold?

And did you know that counting sheep won't help you fall

asleep, and that it might actually keep you awake longer? Let's

get to the bottom of some of the most common myths about

sleep, including how many hours are ideal.

If your schedule allows it, getting part of your needed daily

rest during the day might work best for you.

©Purestock/Thinkstock

Although 40 percent of us are falling short, it won't surprise you

that it's true, on average, that most adults should aim for about

eight hours of sleep, give or take an hour [source:Jones]. How

much sleep we need varies based on age: If you're between age

18 and 64, for instance, your goal should be between seven and

nine hours of sleep, and anyone over 65 should try for seven to

eight hours.

Those who haven't reached adulthood yet need more than eight

hours. Teenagers, for example, need eight to 10 hours, and kids

ages 6 to 13 should be getting between nine and 11 hours per

night. And when it comes to the little ones, we're looking at

between 10 and 17 hours depending on age (3- to 5-year-olds

need 10 to 13 hours; 1- to 2-year-olds need 11 to 14 hours;

infants ages 4 to 11 months need 12 to 15 hours; and newborns,

between 14 and 17 hours) [sources: NSF, Hischkowitz, et al].

It's important to remember, though, that the recommended

guidelines may not be appropriate for everyone, and catching up

with the sandman in small blocks throughout your day rather

than spending the night with him might work out better for some

people. Sleeping eight hours through the night is

called monophasic sleep, but not everyone is a monophasic

sleeper. Leonardo da Vinci, for example, is a famous example of

apolyphasic sleeper, which means he slept in a few segments

throughout the day rather than all at once. In fact, monophasic

sleep cycles are a relatively new thing for humans, changing

around the time that electricity became commonplace. Most

animals arepolyphasic sleepers, and historically humans were

once naturally biphasic sleepers, meaning we slept for four

hours, spent a few hours awake, and returned to sleep for

another four hours [source: Campbell and Murphy].

You may have convinced yourself you need less sleep than

everyone else. That might be true, but the odds are greater

that you’ve just stopped noticing how tired you are.

© Anna Bizoń/iStock/Thinkstock

It's true that there are some people who need just a few hours of

sleep each night. However, it's probably not you or me. The

numbers are quite small; only an estimated 1 to 3 percent among

us can function just fine with only five hours of sleep each

night. Short sleepers, nicknamed the "sleepless elite" tend to run

in families; it's not that they've somehow trained themselves to

need less sleep, though (we'll get to that later). Rather, they

carry a gene variation, hDEC2, that allows them to go without,

and with no apparent consequence [source: Beck]. The rest of

us, well, we just stopped noticing how tired we are.

Too little sleep, though, makes you more than just

drowsy. Sleep deprivation is associated with some pretty severe

health problems, including obesity, heart disease and diabetes.

Get too little sleep -- five hours or fewer per night -- and you

double your risk of death from all causes [source: Peri]. And

once you've been awake for 18 hours, you may be more than

just a little tired. Get behind the wheel of your car at that point,

for example, and you could be mistaken for driving under the

influence.

You can make yourself get up early, but that doesn’t mean

your body has gotten all the sleep it requires.

© Erik De graaf/Hemera/Thinkstock

About half of American adults say they don't get enough sleep

(only 30 percent report that they get, on average, at least six

hours of sleep every day). Many of us rely on coffee or another

source of caffeine to stay awake, and fewer of us take naps. And

at least 45 percent of men polled believe that people can train

themselves to need less sleep [source: Better Sleep

Council, CDC].

Sorry guys, but we can't. Sleep isn't a waste of time, you won't

sleep when you're dead and you can't train your body to function

just fine on very little sleep. During combat, for instance,

soldiers may need to remain awake for long periods of time,

unable to get several hours at one time, perhaps needing to stay

awake for 48 hours or longer. Research conducted by the Walter

Reed Army Institute of Research found that despite all attempts,

humans are unable to adapt to getting fewer hours of shut-eye

than their body requires every day [source: Szivos]. Each of us

has our own sleep requirement, and no matter how hard you try,

your body isn't going to change its mind about that. You may

stop noticing the effects of your sleep deprivation after a while,

but less sleep is associated with heart disease and high blood

pressure in addition to depression, diabetes, weight gain and

even premature death.

Sleeping late on your day off may feel amazing, but if you’re

chronically cutting your sleep short, it won’t make up for

the lost dozing.

©Thinkstock Images

Although you may feel more refreshed after indulging in a long

night of sleep after a week of early mornings, recovering from

your sleep debt — the difference between the hours of sleep

your body requires and the number of you're actually getting —

takes time, and definitely more than just one night of good

sleep. If, for instance, your sleep patterns are similar to the

average American adult, you're sleeping 6.8 hours on weekdays

and a little more, 7.4 hours, on weekend nights. If your sleep

goal is 8 hours a night, your sleep debt ends up totaling more

than two weeks every year [source:Webster].

Eventually, you may settle that debt if it's a short-term deficit

(one all-nighter, for example). But in the case of long-term sleep

debt, you might not be able to. Even if you do repay a short-

term loss of sleep, you're still at an increased risk of developing

the health problems associated with sleep

deprivation [source: Cohen, et a].

When you’re unconscious and lost in dreamland, your brain

is active, performing vital tasks.

© Johan Swanepoel/iStock/Thinkstock

Your brain doesn't take the night off when you're asleep; it's

actually pretty busy while you doze. This is when your brain

forms new memories. It also links memories with older

memories and consolidates memories for long-term storage.

And it does the same with motor skills, too, so if you're learning

a new dance or want to improve your swing, don't skimp on

sleep — it's when you develop muscle memory. While you're

not actually physically making the movements of that new

dance while you snooze, you're processing complex information

and even making decisions — or at least making the links

between information that's important to something in your

waking life.

And, as if that's not enough to keep your brain busy while you

catch some Zs, this is also the time when your brain takes out

the trash. Literally, it's when the body's glymphatic system gets

to work, sending cerebrospinal fluid flowing through the brain

and removing waste products [source: Xie, et al]. If the brain

isn't able to clean up, it leaves you at risk for developing

neurodegenerative diseases such as Alzheimer's and Parkinson's.

Even as you mature, you still need plenty of sleep.

© michaeljung/iStock/Thinkstock

Sleep experts recommend that older adults aim for seven to

eight hours of sleep every night, which, as you can see, is not

much different than the seven to nine hours recommended for

young and middle-aged adults [source: Hirshkowitz, et al]. You

don't need less sleep as you get older, although your sleep habits

are likely to shift with age. Seniors frequently report that while

they don't regularly sleep through each night, they rely on a

daytime nap (or two).

As you age, there are also more things getting between you and

the sandman. As the years pass, your risk of developing sleep

problems increases, including common disorders such as

insomnia, restless leg syndrome and sleep apnea. Often the

cause of lost sleep in later years may look like a bout of

transient insomnia, for example, but your sleep complaint may

actually be caused by other health problems and chronic

conditions such as arthritis, depression or GERD

(gastroesophageal reflux disorder).

Tying one on may make you doze off quickly, but you’re

unlikely to get quality sleep.

© Jelena Jovanovic/Hemera/ Thinkstock

About 20 percent of Americans pour themselves a nightcap in

an effort to get a good night's sleep, and if you're one of them,

that drink you're having before bed may actually be sabotaging,

not helping, the quality of your snooze [source: Thakkar, et al].

Yes, drinking an alcoholic beverage or two before bed will help

you fall asleep faster. That's because alcohol has a sedative

effect on the body's central nervous system — but there's a

catch. If you're three sheets to the wind when you hit the sheets,

that alcohol appears to have an effect on what's known as your

brain's sleep-wake system. Through this system, your brain

regulates and balances when you feel sleepy or awake, in

addition to regulating your sleep throughout the night.

There are two sleep cycles: non-rapid eye movement (NREM)

and rapid eye movement (REM). We spend about 80 percent of

our sleep in NREM sleep; NREM sleep, which is dreamless, is

broken into multiple stages, including deep sleep when the body

is in restoration mode [source: Robinson]. It's the second piece

of your good night's sleep, REM sleep, when you'll really feel

the brunt of the booze. Once your body metabolizes the alcohol

you drank, your sleep becomes restless, and you may wake early

or multiple times during the night, and you may find it difficult

to fall back asleep [source: Thakkar, et al].

To help avoid the sleep-related side effects of alcohol, which

may include headache, night sweats, nightmares and snoring (in

addition to a growing reliance on that evening cocktail), cap

yourself at one to two drinks and don't drink alcohol within

three hours of turning in [source: AASM].

Turkey’s been getting false credit as a sleep aid for years.

©Creatas Images/Thinkstock

Here's the thing about turkey: Everyone knows that turkey

contains tryptophan, and everyone knows that tryptophan will

leave you snoring on the sofa. Well, at least we get one out of

two correct. Let's break it down.

Yes, turkey does contain tryptophan. But, then, so does cheddar

cheese. In fact, an ounce of cheese contains more tryptophan

than an ounce of turkey — and we've yet to hear anyone

complaining how tired they are after ordering the cheese plate

[source:Wanjek].

Tryptophan is an amino acid your body uses as a building block

for producing serotonin, a neurotransmitter that helps to regulate

your mood, your appetite and your sleep cycle, in addition to

melatonin, a hormone that also regulates sleep. It does play a

role in making us sleepy, but here's the thing: You're not

ingesting enough tryptophan, nor does enough of it reach your

brain after a meal — even a big holiday meal — to overtake you

with the urge to nap [source: Young].

As a sleep aid, tryptophan is thought to work most effectively

when taken as a supplement on an empty stomach — and in

much higher doses than you could eat, even with Thanksgiving

seconds (and thirds). While a 4-ounce (113-gram) serving of

turkey contains 350 milligrams of tryptophan, the supplements

popular in the 1980s contained levels as high as 2,000

milligrams [source: Mikkelson]. But a better sleep-aid snack

than cheddar or Swiss is one that contains 1 ounce (30 grams) of

carbohydrates [source:Zamosky].

Staying connected right up to the time you’re falling asleep

is not a good idea.

© monkeybusinessimages/iStock/Thinkstock

Ninety-one percent of Americans adults own a PC or laptop, and

almost half own a tablet. And then there are our phones. Eighty

percent of American adults own a cell orsmartphone; one-third

say they can't even begin to imagine living without them. And

even if you don't consider yourself a smartphone addict, we're

all using them a lot more; in 2014, on average, we used our

smartphones 45 percent more every month than we did in 2013

[sources: GlobalWebIndex, Pew, Cisco]. What are we doing

with our tech? Mostly we text, but we also browse the Web,

play games and use social media — more than we actually use

the phone as a phone.

While staying connected may feel good, nearly half of us sleep

with our phone (and that rises to as many as 74 percent for

people under the age of 34), and the consequences of that habit

aren't so good at all [Source: Pew, Lookout].

You may enjoy falling asleep watching a movie, catching up on

social media or reading an e-book, but the devices you use to do

those things all emit short-wavelength enriched light — blue

light. Research shows that light exposure disrupts the body's

circadian clock and reduces the levels of melatonin produced by

the pineal gland. Reading on an iPad before bed, for instance, is

shown to delay natural circadian rhythm by more than one hour

[source: Chang, et al].

The best advice? Wait until the morning to check your phone —

which 80 percent of us already do as soon as we wake up

[source: Stadd].

Science is still puzzling out why we yawn. It might have

more to do with temperature than tiredness.

© Giulio_Fornasar/iStock/Thinkstock

You and I, on average, will each yawn eight times today

[source: Koren]. While one or two of those yawns may be to

pop your ears after a flight or another change in air pressure,

scientists can't yet fully explain for certain why we yawn — or

why yawning is contagious. But they have ruled out the theory

that yawns mean you're tired. Yawning also won't help wake

you up by increasing the oxygen levels in your bloodstream.

Hippocrates theorized that yawning was the body's way of

releasing noxious air when body temperature began to rise.

Later theories emerged that yawning was the body's way of

increasing the level of oxygen in the blood supply

[source: Robson]. Currently, there are two leading theories as to

why we yawn. One is a social explanation: Yawning is a

primitive form of communication (although what we're trying to

communicate to each other remains unclear). The other

explanation is that yawning is a thermoregulatory function that

cools the brain when its temperature rises as little as 0.18 degree

Fahrenheit (about 0.1 degree Celsius). Humans do yawn more

frequently when they're in a warm environment and when

feeling anxious or stressed [source: Gallup].

5 Health Risks of Too Little Sleep

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running on too little sleep, but not sleeping enough has

implications beyond our general mood. Read more »

Author's Note: 10 Myths About Sleep As it turns out, we spend a lot of time on using our phone,

playing games, texting, using social media. When you total up

all the hours, it adds up to be about 23 days out of the year.

That's 23 days of looking at a small screen. I'm not judging. I

like my phone just as much as anyone else. But during my

research I also discovered that there are apps that can help

reduce the problem that light causes on our sleep cycle. They

work by filtering out blue light and are available for all your

devices, from phone to tablet to computer. And they also come

in physical filters. So if you must sleep with your phone, it can't

hurt to try out a filter.