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The one and only reason you are tired

Сон как причина усталости

Sleep (Latin somnus) is a natural physiological process of staying in a state with a minimum level of brain activity and a reduced response to the surrounding world, inherent in mammals, birds, fish and some other animals, including insects (for example, Drosophila).

In this article, the famous scientist and trainer James Clear has collected everything that science knows about the nature of sleep and gives practical recommendations on how to get enough sleep and become more energetic.

On February 13, 1972, Michel Siffre climbed into a cave in southwestern Texas. He spent the next six months in it, not once in these days seeing daylight. Siffre was not crazy, but a French scientist and pioneer in the field of chronobiology - a science that studies the work of biological rhythms.

The most famous rhythm is the circadian rhythm, it regulates the cycles of sleep and wakefulness. Siffre climbed into the cave to find out how this mechanism works. Siffre lived in a tent. The role of the bed for him was performed by a wooden pallet. He also had a desk, a chair and a telephone - for communication with the research team, which remained outside.

In its underground was one light bulb, which always shone with the same soft light, a large supply of frozen food and a couple of tons of water. And most importantly: there were no watches or calendars on him or him.

His task was to monitor the body, which does not know whether it is day or night, which means that he should sleep or not. So Siffre lived alone in this cave for six months. All this time he was trying to figure out how his biological clock works.

Here is what he wrote in his diary: “I finally got a perfect dream! My body now chooses when to sleep, and when to eat. It is very important. We used to have 24 hours in a day. But the internal clock of our body gives the day a little more - 24 hours and 30 minutes. ”Siffre kept setting new experiments on himself. And he found the perfect formula in the 48-hour cycle: 36 hours of continuous wakefulness, and then 12 hours of sleep.

The work of Siffra and his followers made scientists from the largest universities - Harvard and Pennsylvania - interested in the nature of sleep.

Given the fact that we sleep a third of our lives, it is hard to believe that this topic has become seriously interested in scientists only in recent decades.

Let's start.

How much sleep do you need?

To answer this question, let's look at an experiment conducted by researchers from the University of Pennsylvania and specialists from the University of Washington.

They collected 48 healthy men and a woman who slept an average of 7-8 hours a day. Then they divided into four groups. The first group - volunteers who were deprived of sleep for three consecutive days. The second group - those who slept per day for only four hours. The third group - people who slept for 6 hours a night. Finally, the members of the fourth group had to sleep for 8 hours - no more, no less.

The experiment lasted two weeks. And then all respondents passed tests for mental and physical performance.

Here is what happened.

Those who slept 8 hours a day remained “cucumbers” and passed the tests as well as before the start of the experiment. Meanwhile, those who slept for 4-6 hours showed a steady decline in cognitive abilities, with problems growing every day. More interestingly, there was no noticeable difference between the members of the groups “4” and “6”.

Scientists also found that the need for sleep can accumulate.

A week later, one in four of those groups that did not sleep enough began to “cut down” in random places involuntarily. After two weeks of experiment, members of the group that slept only 6 hours showed the same productivity deficit as those who had not slept at all for two days in a row.

Let me repeat: if you sleep only six hours a day for two consecutive weeks, your mental and physical abilities decrease to the level as if you were awake for 48 hours in a row.

The second important point: the participants in the experiment themselves did not notice that their performance was declining.

When the participants in the experiment were given the opportunity to independently evaluate their effectiveness, then all of them, as it turned out, overestimated themselves. In other words, we are not able to adequately evaluate ourselves and our productivity. So, it may seem to us that chronic lack of sleep is normal. Or even that we don’t need all 8 hours. But this is not so.

We live our lives in bright offices, conduct social conversations and consume a huge amount of caffeine. Those. we have a lot of tools that allow us to feel awakened, although in reality everything is more serious.

Lack of sleep

The irony of the situation is that many of us consciously deprive ourselves of normal sleep in order to increase our productivity, in order to do more. But in fact, we only harm our plans.

In the United States alone, studies show that chronic lack of workers causes their employers to lose a total of $ 100 billion a year due to the regular lack of sleep.

Grigory Belenky, director of the Research Center for Productivity Studies at the University of Washington, explains: “Unless you are doing work that doesn't require any mental skills at all, by depriving yourself of sleep, you are trading waking hours to the detriment of productivity” .

This brings us to an important question: how do you know if you have enough sleep or not?

A wide range of studies has shown that, as a rule, for 99% of people on the planet, seven and a half or eight hours are needed. This is if we are talking about optimal values.

Experts agree that 95% of adults in order to live a normal life should sleep every night from 7 to 9 hours. If they sleep less, they will begin to lose their mental and physical performance. Children and the elderly, as a rule, need to sleep even more. Meanwhile, people sleep less and less.

Harvard Medical School claims that the average duration of sleep for Americans has decreased from 9 hours in 1910 to 7 hours today. Dr. Lawrence Epstein of this institute claims that 20% of Americans even sleep less than six hours a day.

How to sleep

A process called the sleep and wake cycle determines the quality of your sleep.

He has two stages:

  • Slow sleep phase (deep sleep)
  • REM sleep phase (when we have dreams, and when it is easy to wake us up).

During slow sleep, the body relaxes, breathing becomes slow and deep, blood pressure drops, the body becomes less sensitive to external stimuli. Waking up is hard.

This stage is crucial for the restoration and "repair" of the body. During slow sleep, the pituitary gland actively secretes growth hormones. They stimulate tissue growth and muscle repair.

Researchers also believe that the body’s immune system also has the opportunity to rest during this stage. This dream is especially important if you are an athlete.

It is known that before important competitions, LeBron James and Roger Federer sleep 11-12 hours a day. And this is no accident. Researchers at Stanford University have proven that basketball players who sleep more than 10 hours a day show better results in shot accuracy and speed of response to unexpected situations.

Basketball players usually sleep 8 hours a day. But if you let them sleep for ten hours, then the accuracy of three-point throws increases by 9%, and in the sprint by 80 meters they turn out to be faster by 0.6 seconds faster than usual. It's a lot. And all because the phase of slow sleep helps us recover our muscles faster.

Now let's talk about the phase of slow sleep .

At this time, your brain creates dreams and reorganizes information, systematizes it. Neurons also grow rapidly at this time. Therefore, in the morning, your memory works better, and in the morning you find it easier to learn.

During REM sleep, heart rate, pressure, and body temperature, on the contrary, increase. You should have three to five such faces per day. If you deprive yourself of any of these two phases of sleep, your body literally begins to die.

If you lack sleep, you cannot recover yourself physically. Your immune system weakens, your consciousness becomes foggy. You have an increased risk of contracting a viral infection. You gain weight, you begin to develop diabetes, problems with pressure.

A little more - and you will learn what heart diseases, mental illness and premature mortality are.

A brief conclusion: you need a slow sleep for physical recovery, fast - for the mental. Since the quality of your sleep worsens over the years, in order to stay young longer, you need to sleep even more.

Age changes

Harvard Medical School claims that the older you are, the more difficult it is for you to fall asleep. And the worse your dream is doing with its functions.

Based on the above data, it can be said that the average 80-year-old man gets a whopping 62% less “slow” sleep than the average 20-year-old man. And this is one of the reasons why cell tissues age so quickly in adults.

If old people have trouble sleeping, you can be sure that their aging process is now accelerating rapidly. And you need to seek help from a somnologist.

There is no doubt: a good and healthy sleep is the key to protection from premature aging.

How to recover if you are sleep deprived

Specialists from Harvard Medical School give only one recommendation: you need to sleep during the day . At least a little: 20-30 minutes . This will be enough to help your brain "get together."

When to go to bed, and when to wake up

As you already know, sleep and wake cycles are called circadian rhythms. It determines when you need to sleep.

But here are a few common points for all:

  • At 6am, cortisol levels increase, which helps wake your brain and body.
  • At 7 a.m., the body stops producing the sleep hormone melatonin.
  • At 9am - Your sex hormones are at their peak performance.
  • 10 am is the peak of your mental activity.
  • 2.30 days - peak for your systems responsible for motor skills and coordination.
  • 3.30 days is the time when you have the best reaction time.
  • 5.00 a.m. - the time when your cardiovascular and muscle systems work best.
  • 7 pm is a time of high blood pressure and fever.
  • 9 pm - the time of the start of production of melatonin. The body prepares the body for sleep.
  • 10 pm. - You often want to use the toilet. The body continues to prepare for bed.
  • 2 a.m. - The time of the deepest sleep.
  • 4 a.m. - The time when you have the lowest body temperature. Waking at this time is especially harmful.

Obviously, all of these periods may vary slightly for different people. But they show the big picture.

How to reset?

Circadian rhythms change depending on how you behave and what you do during the day.

How to reset this “clock” and start it again?

The easiest and most proven way: peer into bright light for 30 minutes. Those. You can spend half an hour outdoors on a sunny day without sunglasses. Better yet, wake up at dawn and spend the morning on the balcony.

How to sleep properly. A few recommendations.

Avoid Caffeine

If you have trouble falling asleep, remove caffeine from your diet. If you are not able to deny yourself a morning cup of coffee, then do not drink it at least in the afternoon.

Quit smoking or chewing tobacco

Tobacco use causes sleep problems. How to quit? They say the best book on the topic was written by Allen Carr. It is called "An Easy Way to Quit Smoking . "

The bedroom is a room only for sleeping and sex.

Spend a lot of time in the bedroom? Watch TV in it? This is your main mistake. Remove from the bedroom everything that distracts you: TV, laptop, tablet, smartphone. And one more thing: curtains should be tight. So dense that at night in this room was absolute darkness.


If you can’t get enough sleep, try light exercises after you get home from work. This will help your body and brain disconnect faster. You need to do exercises at least two to three hours before bedtime. Otherwise, you will only harm yourself.


Most people sleep best in a cool room. The ideal range is 18-21 degrees Celsius.


Perfect silence is the best. But if you can’t drown out the sounds of the street, use white noise. You can turn on a regular fan or install a special application on your smartphone. Another good option is earplugs.


This is a slippery slope. Yes, many people get drunk at bedtime to quickly disconnect. But at the same time, alcohol reduces the quality of sleep and delays the phase of "fast" sleep. As a result, your brain is resting, but your body is not. That is why in the morning you often wake up completely broken.

Stick to regular sleep

The body loves rituals. Circadian rhythm is the foundation of our daily lives. Go to bed and wake up at the same time on weekdays and weekends.

Develop a bedtime ritual

Avoid the light from computer screens, televisions, and mobile gadgets before going to bed. The blue light they emit suppresses the production of melatonin in the body. As a result, you cannot fall asleep, and your brain drives unpleasant thoughts in a circle every time you are in bed.

Along the way, instead of melatonin, the body produces the stress hormone cortisol - and it is the main enemy of your sleep. So before going to bed, for example, just start reading a book. This is an ideal way to prepare yourself for a night's rest.

Another option is to download the F.lux application, which in the evenings reduces the brightness of the monitor and removes, as far as possible, the blue color from its spectrum.

You must have a relaxation technique

Researchers estimate that at least 50% of cases of insomnia are caused by stress. Find a way to deal with it every day. It was verified that such methods as reading magazines, deep breathing exercises, meditation, physical exercises and keeping a diary work (there you need to write about what you are grateful for every day for).

How to get more energy in the morning

Drink a large glass of water early in the morning. Your body was without water for six to eight hours. That's why in the morning you feel so lethargic. Almost always, it is all about dehydration. The first thing I do when I wake up is to drink a large glass of water.

Start the day with sunshine

Sunlight is the new coffee. If you early in the morning stand on the balcony or at the window (from the side where the sun rises) and spend a few minutes there, this will instantly wake you up. And it will set the brain the right mood for the whole day.

Coffee is a way to wake up on cloudy days and in winter, when you have to get up before sunrise. The rest of the time it is better not to drink it.

In general, why are we all this?

Sleep deficiency, and even more so if it is chronic, is the same burglar who takes away your working capacity, mind, physical health and good mood.

Our culture underestimates the importance of good sleep. So try to sleep more. Sounds easy, right? How about a try?