Sleep Science
Sleep science has developed significantly in the past 20 years, providing growing insight about how sleep works, why
it’s important, and the ways that it can be disrupted.
Despite this advancing science, it remains common to encounter misinformation about sleep that is spread online, on
social media, or by word-of-mouth. Some of this false information becomes repeated so often that it becomes a widely
held myth.
Even though these sleep myths are contrary to scientific evidence, they are often believed and can lead to poor sleep
habits and insufficient sleep.
In 2019, the National Sleep Foundation gathered a panel of experts to identify the most prominent and problematic sleep
myths. Reviewing these and other myths is an opportunity to learn the facts, set the record straight, and find ways to
help get the sleep that you need.
Myth: Your Body Gets Used to Getting Less Sleep
Research has found that a lack of sleep takes a toll over both the short- and long-term, demonstrating that your brain
and body can’t just get used to getting less sleep.
After a few nights of insufficient sleep, you’re likely to feel sleepier during the day. This increase in daytime
drowsiness may stabilize over weeks or months without enough sleep, but this doesn’t mean that your body is
functioning on all cylinders or is effectively adjusting to sleep loss.
Instead, persistent sleep deprivation affects daytime performance, harming decision-making, memory, focus, and
creativity. With time, insufficient sleep can wreak havoc on diverse aspects of health including metabolism, the
cardiovascular system, the immune system, hormone production, and mental health.
As a result, even if it seems like you are getting accustomed to sleeping too little, in reality, more serious
health problems may be accumulating because of the body’s inability to get the rest it needs.
Myth: Many Adults Need Five or Less Hours of Sleep
Recommendations from a group of experts commissioned by the National Sleep Foundation state that adults should get
between seven and nine hours of sleep per night.
While a very small number of people — estimated at around one in four million4 — are believed to have a genetic
mutation that allows them to naturally sleep for shorter periods and still wake up refreshed, these individuals are
the rare exception, not the rule.
Myth: Many Adults Need Five or Less Hours of Sleep
Recommendations from a group of experts commissioned by the National Sleep Foundation state that adults should get
between seven and nine hours of sleep per night.
While a very small number of people — estimated at around one in four million — are believed to have a genetic
mutation that allows them to naturally sleep for shorter periods and still wake up refreshed, these individuals are
the rare exception, not the rule.
Myth: It Doesn’t Matter When You Sleep As Long As You Sleep Enough Hours
Studies have demonstrated that the timing of sleep matters, and it’s best to sleep as much as possible during hours
of darkness. Sleeping at night helps align the body’s circadian rhythm, or internal clock, with its environment.
Proper circadian timing is important for sleep quality7 and affects mental health, cardiovascular function,
metabolism, and other key elements of overall health.
Myth: A Good Sleeper Doesn’t Move at Night
Minor movements of the body can occur during normal, healthy sleep. Movements during sleep are generally only a
concern if they are one or more of the following:
- Prolonged or chronic
- Abnormal (such as sleepwalking)
- Abnormal (such as sleepwalking)
- Aggressive or violent
- Bothersome to a bed partner
- Causing nighttime awakenings
Myth: Your Brain Shuts Down During Sleep
The brain remains active during sleep. Its patterns of activity change during different sleep stages, and in rapid
eye movement (REM) sleep, brain activity ramps up to a level that shares similarities with when you’re awake.
Far from shutting down, shifts in brain activity during sleep are believed to be part of why sleep is critical to
effective thinking, memory, and emotional processing.
Myth: Dreaming Only Happens During REM Sleep
The most intense dreams usually happen during REM sleep, but dreaming can occur during any sleep stage. Dreams in
REM and non-REM sleep usually have different content10 with more vivid or bizarre dreams usually taking place during
REM stages.
Myth: More Sleep is Always Better
While most concerns about sleep duration focus on sleeping too little, there are also problems that can arise from
sleeping too much.
People in specific circumstances, such as recovery from illness, may need extra sleep, but excessive sleep, in
general, can be a symptom of an underlying health problem. In addition, studies have found higher rates of
mortality11 in people who sleep too much, but more research is needed to better understand this association.
Myth: Snoring Isn’t Harmful and You Can’t Do Anything About It Anyway
Light, occasional snoring usually isn’t a problem, but loud and frequent snoring is often a cause for concern.
Chronic or loud snoring may be caused by obstructive sleep apnea (OSA), a serious breathing disorder that fragments
sleep and prevents a person from taking in the oxygen their body needs. Snoring can also disrupt the sleep of a bed
partner or roommate.
Various methods can address snoring depending on its cause. Positive airway pressure (PAP) devices that keep the
airway open can help treat OSA. Anti-snoring mouthpieces and mouth exercises can help many people reduce or
eliminate snoring, and in many cases, losing weight can cut down on snoring as well.
Myth: Adults Sleep More With Age
Older adults frequently sleep less than younger people. Aging can affect a person’s circadian rhythm and make it
harder for them to sleep as long as they want. Other health problems that increase with age, such as arthritic pain,
may also interfere with a good night’s sleep.
Myth: The Ability to Fall Asleep Anywhere and at Any Time Means You’re a “Good Sleeper”
Being able to fall asleep at any time and under any circumstances is a sign of having sleep problems, not of being a
“good sleeper.”
This myth is dangerous because it puts a positive spin on excessive daytime sleepiness, which is usually a symptom
of insomnia, insufficient sleep, or an underlying sleep disorder like sleep apnea. Sleeping at any time can also be
tied to circadian rhythm disorders and narcolepsy.
As a sleeper, your goal shouldn’t be the ability to fall asleep in any situation. Instead, it should be to strive
for a proper amount of high-quality sleep that occurs on a regular schedule that, whenever possible, involves
sleeping at night in order to reinforce a healthy circadian rhythm.
Myth: Napping Makes Up for Lack of Sleep at Night
While a quick nap can provide a boost of energy, it’s not a substitute for quality sleep at night, especially
because it doesn’t involve moving through the stages of sleep in the same way as during nightly sleep.
Many people who get insufficient sleep try to use naps to catch up on sleep, but this often just throws their sleep
schedule further out-of-whack by making it harder to fall asleep at a normal bedtime. Long naps can also mean waking
up disoriented and sluggish.
Though napping isn’t necessarily bad, relying on naps to try to cope with regular sleep deprivation isn’t a winning
approach. When you do need a nap, it’s best to keep it shorter than 30 minutes and early in the afternoon.
Myth: Teens Don’t Sleep Enough Only Because They Choose to Stay up Late
A significant number of teenagers, including up to 72% of high school students, get less than the recommended
amount of sleep. In many cases, this is because their sleep schedule involves staying up later into the night.
However, this “night owl” tendency isn’t simply a matter of choice. Instead, it’s a reflection of biological
changes that start around puberty that push the circadian rhythm of adolescents back by around two hours. Of
course, individual choices to prioritize school and work obligations, social events, and screen time over sleep may
exacerbate this biologically delayed sleep timing.
Because of the natural shift in circadian timing in teens, major organizations like the American Academy of
Pediatrics have called for school districts to push school start times back in order to give adolescents more time
to get the sleep they need.
Myth: Turning Up the Radio, Opening the Window, or Turning on the Air Conditioner Are Effective Ways to Stay Awake
When Driving
Drowsy driving is extremely dangerous, and these “tricks” are ineffective and are especially worrisome if they keep
a sleepy driver behind the wheel.
If you’re feeling tired while driving, the best and safest thing to do is pull off the road and into a safe area
where you can nap for 15-30 minutes or simply stop for the night. Caffeinated drinks may help for a short period,
but it can take time for caffeine to kick in. Even then, it’s risky to rely on caffeine to keep you alert when
driving.The best way to deal with drowsy driving is to prevent it in the first place by getting a good night’s sleep
before your trip. When in doubt, err against driving if you’re at all sleepy because the consequences can be
life-threatening to you and others on the road.
Myth: If You Can’t Sleep, It’s Best to Stay in Bed Until You Fall Back Asleep
Sleep experts recommend getting out of bed if you can’t fall asleep within 20 minutes. Instead of tossing and
turning in bed, it’s better to get up, do something relaxing in a quiet and dim setting (without using your cell
phone or other electronic devices), and then try to go back to bed.
The reason experts advise this approach is that it’s important to associate your bed with sleep. Staying in bed
while struggling to sleep can do the exact opposite, linking your bed with a feeling of frustration.
Myth: Alcohol Before Bed Improve Sleep
A drink or two can be relaxing, inducing drowsiness that makes it easier to initially fall asleep. The problem is
that the quality of sleep declines considerably after drinking alcohol. Consuming alcohol before going to bed can
throw off your sleep cycles, make it more likely your sleep will be interrupted, and worsen snoring and sleep apnea.
Because of its negative effects on sleep, reducing or eliminating alcohol consumption before bed is frequently
recognized as an important part of sleep hygiene.
Myth: A Warmer Bedroom is Best for Sleeping
Although a warm bedroom might feel cozier, studies indicate that it’s not ideal for sleep. Body temperature drops
naturally as part of the physical process of sleep, and a bedroom that’s too hot may disrupt that process. Sleeping
hot can be bothersome and interfere with sleep by causing unwanted awakenings.
It’s important to find a bedroom temperature that’s comfortable for you, but most people sleep best in a room in the
mid-60s Fahrenheit.
Myth: Exercising At Night Disturbs Sleep
Data from surveys and research studies indicates that even vigorous exercise at night does not usually affect
sleep. In fact, working out at night helps many people sleep better.
That said, for some people, it may not be beneficial to do extremely intense workouts immediately before going to
bed as this may make it hard for your body to relax and settle into sleep.
Myth: Hitting Snooze Provides Meaningful Extra Rest
The Snooze bar can provide what seems like precious minutes to keep sleeping between alarms, but this time is
unlikely to offer meaningful rest. Fragmented sleep is generally not restorative, so you shouldn’t count on hitting
snooze to help you wake up more refreshed.
Myth: Sleeping With a Light On is Harmless
Even when you’re in bed with your eyes closed, low light can increase the risk of awakenings and may have negative
effects on circadian rhythm. Studies have also found that sleeping with too much light in your bedroom can
increase eye strain and may be associated with notable weight gain.
To promote higher-quality sleep and a more stable circadian rhythm, it’s best to sleep in a bedroom that’s as close
to pitch darkness as possible.
Source: https://www.sleepfoundation.org/how-sleep-works/myths-and-facts-about-sleep
