

The only reason for your fatigue

Сон как причина усталости

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

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

On February 13, 1972, Michel Siffre climbed into a cave in southwestern Texas. The next six months he spent in it, never in those days without seeing the light of day. Siffre was not crazy, but a French scientist and pioneer in the field of chronobiology - the science that studies the work of biological rhythms.

The most famous rhythm is circadian , 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 served as a wooden pallet. He also had a table, a chair and a telephone - to communicate with the research team that was left outside.

In his underground there 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: on it or with him there were no watches and calendars.

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

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

The works of Siffre and his followers made scientists from the largest universities, Harvard and Pennsylvania, become interested in the nature of sleep.

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

Let's start.

How much sleep do you need?

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

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

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

That's what happened.

Those who slept for 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, and the problems grew every day. What is even more interesting, there was no noticeable difference between the members of groups “4” and “6”.

Scientists have also found that the need for sleep can accumulate.

A week later, one out of every four of those groups that did not sleep, began involuntarily "cutting out" in random places. After two weeks of the experiment, the members of the group that slept just 6 hours showed the same lack of productivity as those who did not sleep at all for two days in a row.

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

The second important note: the experiment participants themselves did not notice that their performance was decreasing.

When participants in the experiment were given the opportunity to independently assess their effectiveness, they all, as it turned out, overestimated themselves. In other words, we are not able to adequately assess ourselves and our productivity. So, it may seem to us that chronic sleep deprivation is normal. Or even that we do not need all 8 hours. But it is not.

We live our lives in bright offices, have 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.

The cost of lack of sleep

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

In the United States alone, research has shown that chronic lack of work for workers results in their employers losing a total of $ 100 billion a year due to the fact that employees regularly lack enough sleep.

Grigory Belenky, director of the University of Washington Research Center for Productivity Studies, explains: “If you don’t do work that doesn’t require any mental skills from you, then depriving yourself of sleep, you trade wakefulness at the expense of productivity” .

This brings us to an important question: how do you understand 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, it is necessary to have seven and a half or eight hours. This is if we are talking about the 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.

At Harvard Medical School, it is claimed that the average sleep duration of Americans has decreased from 9 hours in 1910 to 7 hours today. Dr. Lawrence Epstein from this institute states that 20% of Americans sleep at least six hours a day.

How to sleep

The process, called the cycle of sleep and wakefulness, determines the quality of your sleep.

He has two stages:

  • Slow sleep phase (deep sleep)
  • REM sleep phase (this is when we have dreams and when we wake up easily).

During a slow sleep, the body relaxes, breathing becomes slow and deep, blood pressure drops, the body becomes less sensitive to external stimuli. Wake up 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 gets the chance to take a break 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 shown that basketball players who sleep more than 10 hours a day demonstrate the best results in accuracy of throws and speed of response to unexpected situations.

Usually basketball players sleep 8 hours a day. But if you let them sleep ten hours, the accuracy of three-point shots 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 it is the phase of slow sleep that 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, organizes it. At this time, neurons also grow rapidly. Therefore, in the mornings your memory works better, and in the first half of the day it is easier for you to learn.

During “fast sleep”, the pulse, pressure and body temperature, on the contrary, increase. Such faces you should be from three to five 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, 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 disease, mental illness and premature mortality are.

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

Age changes

Harvard Medical School says that the older you are, the harder it is for you to fall asleep. And the worse your dream copes with its functions.

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

If old people have problems with sleep, you can be sure: the process of their aging is now accelerating rapidly. And you need to ask for help from a somnologist.

There is no doubt: a good and healthy sleep is a guarantee of protection against premature aging.

How to recover if you are not enough sleep

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 ready."

When to go to bed, and when to wake up

As you already know, the cycles of sleep and wakefulness are called circadian rhythms. He determines when you need to sleep.

But here are a few points that are common to all:

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

It is obvious that all these periods may differ 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 restart it?

The easiest and proven method: for 30 minutes to peer into the bright light. Those. You can spend half an hour on the street on a sunny day without sunglasses. Even better, wake up at dawn and spend the morning on the balcony.

How to sleep right. Some recommendations.

Avoid caffeine

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

Stop smoking or chewing tobacco

Tobacco use causes sleep problems. How to quit? They say the best book on the subject was written by Allen Carr. It's called The Easy Way to Stop Smoking .

The bedroom is a room just 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 all that distracts you: TV, laptop, tablet, smartphone. And another thing: curtains should be tight. So dense that at night in this room was absolute darkness.


If you can’t get enough sleep, try doing light exercise after returning home from work. This will help your body and brain to quickly disconnect. Doing exercises should be at least two to three hours before bedtime. Otherwise, you only harm yourself.


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


The perfect silence is the best. But if you can’t stop 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 ear plugs.


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

Stick to regular sleep

The body loves rituals. The circadian rhythm is the basis of our daily life. Go to bed and wake up at the same time on weekdays and on weekends.

Develop a bedtime ritual

Avoid light from the screens of computers, televisions and mobile gadgets before bedtime. The blue light they emit suppresses melatonin production in the body. As a result, you can not fall asleep, and your brain, every time you are in bed, drives around unpleasant thoughts.

Along the way, instead of melatonin, the body produces the stress hormone cortisol, which is the main enemy of your sleep. So, before bed, start, for example, just read a book. This is the perfect way to prepare yourself for an overnight stay.

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

You must have a relaxation technique.

Researchers estimate that at least 50% of insomnia is caused by stress. Find a way to fight it every day. It has been verified that such methods as reading magazines, deep breathing exercises, meditation, exercise and keeping a diary (they also need to write about what you are grateful for every day) work.

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 sluggish. Almost always it’s all about dehydration. The first thing I do when I wake up is drink a large glass of water.

Start the day with sunshine

Sunlight is the new coffee. If you stand on the balcony or by the window early in the morning (from the side where the sun rises) and spend a few minutes there, it will wake you up instantly. And give 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 the sun rises. The rest of the time it is better not to drink it.

In general, what are we all about?

Lack of sleep, and even more so if it is chronic, is the same robber 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 trying?