Where did the myth about “8 hours of sleep” come from, and how much sleep do you really need? Myths about sleep: why you shouldn’t sleep eight hours a day I sleep more than 8 hours, what to do

Research says it takes about 10,000 hours to become proficient at something. Considering that the average life expectancy today is about 78 years, and that we spend a third of our lives sleeping, it turns out that a person is capable of mastering the art of sleep twenty times in his life.

So why do so many people today have trouble sleeping? And why aren't they taking it more seriously? In fact, many people don't think about sleep. Our body usually forces us to sleep if we don't have enough of it. It's an involuntary fact of life. But not always.

Somewhere between 50 and 70 million Americans suffer from sleep deprivation, but ask them why and they'll probably say they don't know. For some reason I can’t fall asleep, sleep longer, or for some reason I don’t have enough time to rest.

Fortunately, sleep is still a kind of science, and there are formulas for success and formulas for failure. This means that there are steps to improve it.

Firstly, It's important to dispel the myth of the ideal eight hours. Roger Ekirch from Virginia Tech University at the end of the last century published a study from which it follows: traditionally, people slept in two stages, with a break. Perhaps this was necessary - waking up in the middle of the night allowed you to do other important things: add wood to the fire, keep an eye on whether someone is robbing you, pray, go to the toilet, and even reproduce. Only in the last hundred years or so have we switched gears and started sleeping through the night.

Given all this, it makes sense to tie your daily biorhythms to a more traditional reference point - the sun. Going to bed around sunset and waking up around dawn leads to greater productivity and creativity. If you wake up just an hour earlier, this gives you as much as 15 extra days of conscious existence in a year.

What about improving sleep quality??

There is also science here. A 2002 study found that people who sleep less than 5 hours a day have noticeable cognitive decline. For those who slept 5-7 hours, cognitive abilities initially fell, and then stabilized over time, although at a level below normal. And those who slept at least 9 hours a night continued to function cognitively at the maximum level.

To do this, it is important to practice what any normal scientist or doctor would recommend - hygiene. Sleep hygiene relies on a number of factors, and the more you use them, the better rested you will be and the more alert you will feel in the morning.

Some tips:

— Go to bed and wake up at the same time every day to set your daily biorhythm.

- Use the bed only for sleep and sex to mentally prepare yourself for this.

— Keep the bedroom cool and dimly lit.

- Avoid eating anything heavy, consuming caffeine, alcohol and nicotine close to bedtime.

— Avoid all screens for several hours before bed, especially those that glow in the blue spectrum (smartphones, TVs).

— Drink plenty of fluids, but don’t drink right before bed.

- What if you woke up? Be gentle with yourself, don’t stress too much about this. Do something relaxing—read something light or drink some decaffeinated tea.

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Did you know that over the past 50 years, humanity has reduced its sleep by an hour and a half? After all, who wants to sleep 1/3 of their life? Therefore, we have learned to work while half asleep, and just drink a cup or two of coffee and you will feel invigorated. Of course, one sleepless night will not do us much harm, but chronic lack of sleep can destroy our health.

Chronic lack of sleep has serious consequences for our health: it can lead to diseases such as depression, bipolar disorder, Alzheimer's disease, schizophrenia, diabetes, etc. And ten or more days without sleep can kill us altogether.
Let's find out why we need 8 hours of sleep so much.

Professor Russell Foster, a neuroscientist at the University of Oxford, conducted research that showed that sleep without rapid REM phase weakens our ability to master new tasks and creativity by 3 times. Also, without it, we lose the ability to regenerate. At the beginning of deep sleep, a significant amount of growth hormones are released into the blood, which are responsible for tissue regeneration.

Lack of sleep impairs our cognitive abilities such as attention, concentration, thinking and problem solving, which significantly reduces productivity at work.

Researchers from TIMSS and PIRLS International Study Center in Boston compared the sleep duration of children in different countries of the world. It turned out that where children slept longer, their school performance was better. During sleep, the body releases growth hormone, which children need for proper development.

During sleep, our brain organizes memories and acquired knowledge. If you don't get enough sleep, then there is a high probability that you will not learn new knowledge or information acquired during the day.

More recently, scientists from the University of Rochester in New York have identified the basic function of sleep, which has long remained a mystery to us. It turns out that sleep helps the brain get rid of toxins produced during metabolism. This happens with the help of cerebrospinal fluid. Based on the results of studies in mice, scientists have determined that cerebrospinal fluid flows through the brain and collects “waste” left behind during life. This entire “cleansing” process occurs during sleep. When the brain goes to sleep, cells contract, leaving spaces that allow cerebrospinal fluid to flow and remove waste.

Chronic lack of sleep or insomnia increases the risk of heart attack, arrhythmia, hypertension, stroke, diabetes, and cancer. According to recent studies, lack of sleep contributes to the development of Alzheimer's disease, weakened immunity and can lead to mental disorders. Therefore, if you or your loved ones suffer from insomnia, then be sure to do an electroencephalography, or EEG - a graphic test of brain activity. This is a completely harmless and painless examination that will allow you to quickly identify and diagnose disorders and pathologies in the functioning of the brain.

A person who does not get enough sleep will experience a decrease in reaction speed while driving in the same way as under the influence of alcohol.

According to a published study conducted in 2007, people who sleep less than five hours a day are twice as likely to die prematurely, especially from cardiovascular disease.

Women who sleep only six hours a day are 12 percent more likely to be overweight. With only 5 hours of sleep, this risk increases to 32 percent.

A study conducted in Sweden found that people who sleep little are more likely to choose higher-calorie, unhealthy foods that contribute to excess weight.

A 2007 study of 10,000 people found that people who don't get enough sleep have a five-fold increased risk of depression.

Lack of sleep leads to the body producing large amounts of the stress hormone cortisol, which contributes to the formation of wrinkles. During sleep, the body releases growth hormone, which adults need to increase muscle mass, maintain healthy skin and strong bones. If you sleep too little, your skin has no chance to recover.

A sleepless night wreaks havoc on the human body at the deepest, molecular level and affects its functioning, from hormone levels and mood to brain performance.

Many scientific studies have shown a cause-and-effect relationship between lack of sleep and infertility.

And lack of sleep leads to decreased potency.

According to the observations of experts, chronic lack of sleep leads to a decrease in vitality and performance. Causes malaise, lethargy, decreased mental abilities, depression, and exacerbation of existing diseases. This is probably why with the arrival of weekends or a long-awaited vacation, everyone tries to get enough sleep.

But, as it turns out, prolonged sleep is fraught with unpleasant consequences. The latest numerous observations by scientists show that excessive love for long sleep can even harm human health.

Why can't you sleep more than 8 hours? What are the consequences of long sleep?

According to medical research, prolonged sleep can provoke a number of negative consequences:

reduce your socio-economic status, because the longer you sleep, the more opportunities you miss for successful advancement both in life and in your career;
provoke mental and physiological disorders in the human body;
create favorable conditions for the emergence of many diseases, for example, diabetes;
Sleeping for more than 8 hours can significantly increase the likelihood of developing a stroke;
excessively long sleep - 8 hours or more per day, can easily cause headaches, weakness, lethargy, malaise, nausea, dizziness, darkening of the eyes;
the habit of staying in bed for a long time, especially in the daytime or immediately after eating, can lead to excess weight, simply obesity, and this, as a consequence, leads to prolonged depression, tears, and low self-esteem;
sleep lasting more than eight hours allows blood pressure to become capricious, which, in turn, leads to a lot of side effects;
During sleep, all physiological processes of the human body slow down, blood pressure decreases, blood flows slower, and if you remain in a state of sleep for a long time, the formation of blood clots can begin. Cardiovascular problems due to long sleep will not bring anything good to anyone;
According to many scientists, long sleep significantly shortens life, and this is especially true for those who strive for longevity.

Preventive measures to improve sleep

For an active life, a middle-aged person needs to sleep 7 hours a day and in no case more than 9.
If a person sleeps more than eight hours a day and wakes up tired, there are reasons for this. To obtain professional advice, you should consult a doctor, who will prescribe a medical examination to determine the cause of oversleeping.

Nevertheless, we need to reconsider our attitude to life, give up bad habits (smoking, alcohol), and strong coffee at night. Create an individual daily routine, find a place for exercise, proper balanced nutrition. Ventilate the bedroom every night.
It is equally important to know that not only too much sleep is harmful, but also lack of sleep.

Are you sleeping correctly? How much rest do you get during sleep? What happens in the body when we sleep? These questions are natural, because a person spends about 24 years of his life in sleep! Agree, you need to get the maximum benefit from this - well, you can’t spend 24 years of your life somehow. Scientists conduct numerous sleep studies, doctors use therapeutic sleep in their work, even traditional healers claim that sleep is health. But speculation is speculation, and in studying a topic one can and should rely only on scientific facts.

Oversleep or undersleep – which is better?

How much sleep do you need to get enough sleep? Almost everyone knows that a night's sleep should last at least 8 hours - that's what doctors tell us. Indeed, many of us will agree that only after 8 hours of sleep do we feel rested. Better yet, sleep 9-10 hours... But psychiatrist, Professor Daniel Kripke specifically conducted research on sleep duration and came to an interesting conclusion:

People who sleep 6.5 to 7.5 hours a night live longer. They are more productive and happier. And excessive sleep can even be harmful to health. And you may feel worse after sleeping for 8.5 hours than if you slept for 5.

Try to conduct an experiment on yourself and sleep not 8 hours, but only 7.5 - just listen carefully to your inner state, to your well-being. Kripke claims that with this sleep pattern the body feels more energetic, the person is ready to literally “move mountains,” and the mood will be excellent.
Are you more often content with 4 hours of sleep a night and consider yourself a hero? You are wrong! Lack of sleep is just as bad as oversleeping. Moreover, it is not known for certain what will have a more negative impact on health. It’s like choosing the size of underwear - each person needs an individual approach. Therefore, you should gently and unobtrusively experiment with your own body - if you sleep 8 or more hours every night, then safely reduce this time by half an hour. Do you feel that 7.5 hours is enough to rest? Try reducing the duration of rest by another half hour. Important:less than 6 hours of sleep a night is harmful. Therefore, when experimenting, do not overdo it - you need to find a “golden mean”. An interesting fact is that a person who has slept for 4 hours will be quite adequate and even so attentive that he can compare with a person who has slept for 7.5 hours. And even tests/exercises performed on these two people will give the same results. What's the catch? The fact is that even with complete sleep, the human brain periodically loses focus on the task. And this is where the difference between the two people that was mentioned at the beginning appears - with a full amount of sleep, the brain returns attention, but if there is a lack of sleep, then there will be no refocusing. In order not to put pressure on you, the readers, with scientific terms, but to convey the idea, we can formulate this:

The brain of a sleep-deprived person works normally, but from time to time something similar to a power failure in an electrical appliance happens to it.

The quote belongs to Clifford Saper: a Harvard professor who, together with a team of other scientists, studies sleep. Just look at the table below:
As soon as a person loses focus, activation processes automatically begin in the brain - they are indicated in yellow in the figure. If a person has not slept enough, then such activity is manifested very weakly or completely absent. But the so-called “center of fear” begins its work (amygdalas - they are highlighted in red on the table) and the brain works in a specific mode - as if the person is in danger from all sides. Physiologically, this is manifested by sweating of the palms, rapid breathing, rumbling and colic in the stomach, and tension of certain muscle groups. Important:The danger of sleep deprivation is that a person loses attention and focus without realizing it. He believes that he reacts adequately to the current circumstances and his productivity does not suffer. This is why doctors recommend not driving a vehicle if you are sleep deprived.

Research on the effects of sleep on humans

Research into the effects of sleep on humans has led to several stunning conclusions:

Sleep disturbance, namely its insufficiency, leads to memory impairment. An experiment was conducted with bees - after they were forced to change their usual route of flying around the territory, the disruption of rest (bees do not sleep in our understanding of the word) led to loss in space - not a single representative of these insects was able to repeat the flight path studied for the day before.
Lack of sleep leads to increased... This is also confirmed by research; scientists associate this manifestation of lack of sleep with what an overworked/unrested body experiences.
Normal, full sleep significantly increases creativity. For example, in a dream one dreams of unexpected solutions to global problems, a person comes to an understanding/vision of some theories - and one does not have to look far for an example: Mendeleev dreamed of a table of chemical elements!
Sleep disturbance can be caused by increased background lighting in the evening. Quite serious research has been conducted on this matter by the University of Chicago Medical Center. It was found that this fact provokes a later bedtime and reduces the duration of the sleep phase that precedes awakening.

In addition, sleep duration may influence food preferences. An experiment was conducted with children aged 6-7 years: with regular lack of sleep, children began to eat more meat, carbohydrates and fats, almost forgetting about fruits and vegetables. All this happened against the background of the absence of any diet - scientists noted classic overeating in a group of tested children. It has long been known that the lack of adequate sleep negatively affects neurotransmitters in the brain - they are simply depleted. The result of such exposure can be stress, because it is the neuroregulators that are responsible for a good mood. It turns out to be a chain: lack of sleep - irritability - stress. And the consequence of a stressful state can be a dangerous and complex condition that must be subjected to professional treatment.

How to regulate sleep

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Too much sleep is harmful, but not enough sleep is also dangerous. What to do and how to determine how much sleep you need specifically? Firstly, if a person feels constantly tired and always wants to sleep, then this means only one thing - it is necessary to adjust the time of daily sleep. And this does not mean that you need to set aside a day, simply sleep, turn off the phone and the doorbell - this will only have a short-term effect. It is necessary to increase the duration of night sleep:

try to go to bed as early as possible;
Before going to bed, do not watch TV or engage in too active work;
It is advisable to take a short walk in the fresh air before going to bed (without beer or strong coffee!), you can read a book - is this advice too banal? But it is very effective - it has been tested, as they say, for years.

Secondly, train your body to rest during the daytime. Some people absolutely need to sleep for at least an hour and a half during the day - they will feel great in the evening and not experience fatigue. But it would be wiser to gradually accustom yourself to rest for a maximum of 30 minutes during the day - don’t be surprised, such a quick sleep is quite enough to restore the normal functioning of the whole body. Thirdly, you need to adjust your sleep routine. You need to go to bed and get up at the same time - if this is problematic, then use an alarm clock. And even if it’s very difficult to get up at 7 am, don’t stay in bed - a couple of minutes of active wakefulness (going to the toilet, hygiene procedures, making coffee and a sandwich) is enough to wake up. If you don’t know how much sleep you need, then pay attention to the data below:

Age/position
Babies	At least 16 hours a day. More often than not, babies require up to 18 hours of sleep per day.
Preschool age	Children should sleep at least 11 hours a day. It is better if the child gets an average of 12 hours of sleep.
School age (up to 15 years)	Schoolchildren should sleep at least 10 hours a day. Taking into account the activity of children and existing associated factors, sleep duration can be increased to 12 hours.
Adolescence	Sleep takes at least 9 hours a day, but no more than 10 hours.
Adults	Sleep should take at least 7 hours per day, ideally you should sleep 8 hours in a row.
Old men	Daily sleep should last 7-8 hours. But given frequent awakenings and intermittent sleep (a feature of age), you definitely need to rest during the day - at least 1 hour.
Pregnant women at any stage	The duration of sleep is 8 hours; during the day you should definitely rest for at least 1 hour, but no more than 2.
Sick	Sleep duration is 8 hours, additional hours of sleep are necessary.

Of course, the table cannot be taken as indisputable data - these are just recommendations. But you can “start” from them when creating an individual sleep and wakefulness schedule. In some cases, the body requires more sleep than indicated in the table. This may indicate health problems, or simply be a necessity in a particular case. For example, pregnancy, emotional outbursts (exams, competitions, etc.), too much physical activity - all this is considered normal, but automatically prolongs sleep time. Note: If sleep disturbances, fatigue and irritability suddenly appear for no apparent reason, then you need to consult a doctor. Most likely, these signs will indicate health problems. Sleep is unconditional health. Therefore, you should not ignore emerging problems with falling asleep, intermittent sleep, or feeling tired after waking up. And it also makes no sense to take sedative and hypnotic medications - they should be selected by a specialist, and these medications will not solve the problem. Even with minor but persistent sleep disturbances, it is necessary to undergo a full examination - the cause of this condition may lie in any organ/system. Tsygankova Yana Aleksandrovna, medical observer, therapist of the highest qualification category.

At first glance, everything seems simple: in order to get a good night’s sleep, you just need to sleep longer. But if you are a fan of such “simple” solutions, Lifehacker has bad news for you.

Why sleeping a lot is just as bad as sleeping a little

Lack of sleep has a lot of side effects: from fatigue and loss of concentration to the inability to feel like a person without being completely overwhelmed. They are known to anyone who has passed difficult exams or is too familiar with the phrase “tomorrow morning is the deadline.” However, oversleeping is fraught with serious troubles.

During a large-scale study Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies, covering almost one and a half million adults, an interesting statistical pattern was established. People who sleep less than 6 hours a night have a 12% greater risk of dying prematurely from any health problem than those who get the standard 8 hours of rest. But for those who like to sleep longer than 9 hours every day, the risk of dying prematurely is even higher - up to 30%!

And the desire to spend more than 8–9 hours in sleep, if it accompanies a person constantly, is a dangerous marker Self-Reported Sleep Duration and Quality and Cardiovascular Disease and Mortality: A Dose-Response Meta-Analysis cardiovascular diseases.

In general, sleeping longer is sometimes, of course, a good option. But it’s better not to play around and try to keep your sleep within certain norms. Moreover, these norms have already been calculated.

How much sleep do you need to be productive and healthy?

Specialists from the American National Sleep Foundation took this issue seriously. They formed an expert group of the world's leading scientists - sleep professionals, as well as representatives of the most authoritative organizations in the field of health care: neurologists, psychiatrists, gerontologists, pediatricians...

For two years, researchers carefully studied scientific publications and reports related to sleep and its effect on the body and well-being. As a result, updated recommendations appeared How Much Sleep Do We Really Need? regarding the duration of rest depending on age.

Here's how much sleep you need to stay healthy:

Newborns (0–3 months) - 14–17 hours.
Infants (4–11 months) - 12–15 hours.
Toddlers (1–2 years) - 11–14 hours.
Preschoolers (3–5 years old) - 10–13 hours.
Junior schoolchildren (6–13 years old) - 9–11 hours.
Teenagers (14–17 years old) - 8–10 hours.
Boys and girls (18–25 years old) - 7–9 hours.
Adults (26–64 years old) - 7–9 hours.
Seniors (65 years and older) - 7–8 hours.

The variation in numbers is due to the individual characteristics of each person. And this is understandable, because the amount of sleep we need depends not only on age, but also on lifestyle, activity level, and general health.

However, the boundaries of healthy sleep are still quite categorical. If you sleep more or less than the amount of time indicated for your age group, we are most likely talking about sleep disorders - with certain health consequences.

The only way to start is to try to “fit” your sleep duration into a healthy framework.

When to go to bed to get enough sleep

Most often, the problem of lack or excess sleep is caused by two things:

You can't go to bed on time.
You can't wake up on time.

And if the solution to the first point is largely related to self-discipline, then in the second case the situation is more complicated. It often happens that, having honestly gone to bed at 23:00, we wake up when the alarm clock rings, for example, at 6:30. But at the same time we feel completely overwhelmed - although the recommended norm seems to have been met.

The reason is that sleep is a cyclical phenomenon. It consists of 5–6 time periods lasting about 90 minutes https://www.psychologytoday.com/us/blog/between-you-and-me/201307/your-sleep-cycle-revealed every. At the beginning of the cycle we fall asleep, closer to the middle we sleep soundly. And by the end, the body is ready to easily wake up - from an alarm clock or, say, sunlight.

Summary: to wake up quickly and vigorously, set your alarm clock correctly. You can calculate the time to start it yourself - for example, with the help of Lifehacker.

Another option is to use one of those that track your sleep quality and wake you up at the most opportune moment.