Sleep is one of the most mysterious processes that occur in human body. And one of the most significant, since we spend almost a third of our lives sleeping. And complete sleep deprivation, even for a relatively short period of time of a few days, can lead to neurotic disorders and imbalance of the entire body. Sleep is very difficult process, in which brain activity changes and vital important functions body. Scientists were able to identify the phases of slow and fast sleep, which have their own characteristics and purposes.

A little history

They tried to study sleep back in Ancient Greece. True, the explanation of what was happening at that time was more mystical than scientific. It was believed that during sleep the immortal soul could rise to higher spheres and even descend to kingdom of the dead. Slightly modified, this interpretation of sleep lasted in scientific circles until the mid-19th century.

But even after scientists established that sleep is caused by the functioning of the human nervous system and brain and has nothing to do with the immortal soul, it was impossible to conduct full-fledged research due to the lack of suitable equipment. It was only in the second half of the 20th century that it became possible to record nerve impulses emanating from muscles and the brain, which made it possible to determine the level of their activity.

With the help of electrical devices, many important discoveries have been made in the field of sleep. Rapid and slow-wave sleep were discovered, various types of insomnia were studied, and the processes occurring in the body during lethargic sleep were studied.

Scientists were able to reveal that human activity is regulated by circadian rhythms - daily alternations of periods of sleep and wakefulness, which continue to work even if it is impossible to navigate in time due to the lack of clocks and sunlight.

Computed tomography and magnetic resonance imaging have allowed us to study in more detail brain activity, which looks completely different during REM and slow-wave sleep. Interesting processes happen to a person when falling asleep, when the body and brain begin to slowly switch off and plunge into a state of deep relaxation, but at the same time certain parts of the brain continue to work.

But the most ambitious discovery was that the reactions of the brain and body to a vivid dream that a person sees in the REM phase are practically no different from reactions to real events. And this means that a person is literally“lives” his dream physically and mentally. But first things first.

Falling asleep

A person who wants to sleep is always easy to recognize, even if he tries to somehow hide his condition. Signs of drowsiness include:

A sleepy person begins to stretch, rub his eyes, and turn around in search of a position comfortable for falling asleep. This condition is associated with an increase in the concentration of a special hormone in the blood - melatonin. It gently inhibits the activity of the nervous system, promoting deeper relaxation and speeding up the process of falling asleep.

The hormone has virtually no effect on the quality of sleep itself. Melatonin is only a natural regulator of circadian rhythms.

The process of falling asleep in a healthy adult lasts from 20 to 40 minutes. If the duration of falling asleep remains constant for more than an hour, we can talk about the presence of one of the many forms of insomnia and it is better to take measures to eliminate it before it turns into chronic form. Natural products can help with this sedatives, taking additional doses of melatonin or proven folk remedies.

Slow phase

Having gone through the stage of falling asleep, a person plunges into slow-wave sleep. It got its name because of its slow rotation eyeballs, which can be observed in a sleeping person. Although it's not just them. During slow-wave sleep, everything vital signs the body is slowed down - the body and brain relax and rest.

As they studied this phase, scientists made more and more new discoveries. As a result, it was discovered that in infants slow sleep has only two stages, and in children over 1-1.5 years old and adults - as many as four, through which the body sequentially passes:

All four stages of the slow phase take approximately one and a half hours, plus or minus 10 minutes. Of these, about a fifth of the time is occupied by deep and very deep dream, and the rest is superficial.

Moreover, a person usually goes through the first stage of slow-wave sleep only after falling asleep, and when slow and fast sleep alternate during the night, it “falls out.”

Fast phase

Scientists have not fully figured out what REM sleep is, how such strange processes can occur in the body, and what significance it has for humans. If everything is more or less clear with slow sleep - this is a period of active recovery of the body and complete relaxation, then the reactions of the brain and the vital functions of the body during REM sleep are completely different.

During REM sleep, a person's eyeballs under closed eyelids begin to move quickly along a chaotic trajectory. From the outside it seems that a person is closely watching something. In fact, this is so, since it is in this phase that dreams appear. But eye movement is not the only and far from the main difference between REM sleep.

What was seen on the encephalogram, and later on the tomogram of the brain during the fast phase, so amazed scientists that it received another name: “paradoxical sleep.” All readings during this period may be practically no different from those taken in a state of active wakefulness, but at the same time the person continues to sleep:

In fact, the entire body is “turned on” in the dream as if it were a real event, and only the person’s consciousness is turned off. But if you wake him up at this moment, he will be able to tell the plot of the dream in great detail and at the same time will experience emotional experiences.

Interestingly, it is during REM sleep that changes occur hormonal levels. Some scientists believe that it is necessary for emotional “reset” and balancing of the endocrine system.

Having experienced exciting events again during sleep, a person then sends these memories to the subconscious, and they stop bothering him.

REM sleep also helps in regulating the level of sex hormones. Nocturnal erections, wet dreams and spontaneous orgasms occur during this phase. Moreover, they are not always accompanied by dreams of an erotic nature.

At the same time, most heart attacks or strokes occur, due to the fact that the relaxed heart and blood vessels are subjected to sudden stress.

At the beginning of the night, the fast phase does not last long - from 5 to 10 minutes, and a person spends most of the time after falling asleep in slow-wave sleep. But in the morning the phase relationship changes. The periods of REM sleep become longer and longer, and the periods of deep sleep become shorter and shorter, and at one point the person wakes up.

Proper awakening

An interesting fact is that a person’s activity and condition, especially in the first half of the day, depends on how he woke up. If he is awakened by external stimuli (alarm clock, bright light, sharp sounds, shock) during the slow phase of sleep, he still needs some time to “come to his senses.” In the first seconds, he may not even understand where he is, some parts of the brain are still so inhibited.

It is a completely different matter if the awakening occurs during REM sleep. The body is already alert and active, you just need to turn on your consciousness. A person who wakes up in this phase feels great, can quickly get out of bed and go about his business. At the same time, he perfectly remembers the last dream and can write it down or retell it.

The modern rhythm of life demands high requirements to the level of physical activity. Perhaps that's why in Lately The so-called “ smart alarm clocks", which read the body's readings and send a signal just in the stage of REM sleep.

The advantage of such a device is that it greatly facilitates awakening, but the disadvantage is that it can wake a person up 20-30 minutes before the set time, since it begins to track sleep phases in advance, calculating the appropriate moment.

But even if you woke up easily, doctors do not advise jumping out of bed right away. Give the body 5-10 minutes for all organs and systems to smoothly start working. Stretch, lie down, tune in to the new day, go over your plans in your head again. And when you feel that you are completely ready for active actions- get up and start your morning routine.

Prevention of insomnia

Healthy quality sleep is considered to be a state in which a person quickly falls asleep and smoothly moves from one phase to another, waking up at the end of the night at his usual time on his own, without an alarm clock. Unfortunately, few people can boast of this today. Chronic fatigue, stress, poor nutrition, negative emotions greatly reduce the quality of sleep and become increasingly common reasons development of chronic insomnia.

To avoid this problem and the multiple troubles associated with it - from neuroses to serious psychosomatic diseases, try to take at least basic measures that can ensure normal quality of sleep:

And most importantly, do not reach for sleeping pills even if you have been unable to fall asleep for several nights in a row. Similar drugs They quickly become addictive and in most cases deprive a person of the rapid phase of sleep.

Under the influence of a sleeping pill, a “heavy”, very deep sleep without dreams occurs, which is very different from normal - after it the person still feels broken.

If problems with falling asleep or frequent awakenings at night have become protracted, you are often tormented by nightmares, or your loved ones talk about you walking at night, go to the doctor. The problem cannot be solved without finding out the cause that provoked it. And this can only be done after examination and consultation with several specialists: a neurologist, an endocrinologist, a somnologist.

But in most cases, temporary insomnia occurs as a result of stress or severe fatigue and can be easily dealt with using folk remedies: warm baths, milk at night, relaxing massage, aromatherapy. A positive attitude is equally important. You can significantly improve the quality of your sleep simply by weaning yourself from thinking about problems in the evenings.

Most people only know in general terms what phases of sleep exist and what happens in the body after we close our eyes. Moreover, each phase is important and affects the quality of rest and human health in general.

Sleep is an unusual state of the body, which is sometimes compared to death. In fact, they have little in common. In contrast to the complete death of the body, rest, on the contrary, promotes long life. It renews all systems, helps restore physical and moral strength.

At the same time, sleep is not something homogeneous in structure. There are different phases, each of which performs a specific function and lasts a very specific amount of time. Everyone knows that deep sleep is beneficial. But when it occurs, how it affects the body - only a few know about it.

Sleep functions

While awake, people and animals spend a lot of energy. Sleep is one of the body’s self-regulation mechanisms that helps restore this energy. Its main functions are:

• relaxation of the nervous system;
• restoration of physical strength;
• “rebooting” the brain (at night the information received during the day is processed, systematized and stored);
• cleansing the body of toxic substances(it’s not for nothing that doctors recommend that sick people sleep more);
• restoration of immunity;
• cell renewal;
• an opportunity to wait out the period of darkness with benefit for the body.

Prolonged deep sleep helps improve memory, burn excess fat, and overcome stress and illness.

What is the functional difference between deep and REM sleep?

During different phases, the brain processes information differently. REM and NREM sleep help you remember events that have happened and plan your future, but each in their own way.

The slow-wave sleep phase “switches on” memory resources. When a person falls into deep sleep (aka slow sleep), all the information received during the day begins to be systematized and “sorted out.” This phase improves memorization and logical thinking.

The REM sleep phase is a real “workshop” of the future. With its help, the brain simulates possible options development of expected events. It’s not for nothing that they say that you had a “prophetic” dream. In itself, of course, it is not prophetic. It’s just that during the period of REM sleep, a person developed models of the future, one of which he realized when he woke up. All this happens on a subconscious or intuitive level. However, human rest is not limited to these two phases. It has a more complex structure.

Phases and stages

There are 4 main stages of sleep:

1. Falling asleep.
2. slow sleep.
3. Fast.
4. Awakening.

Each phase is characterized by a certain duration and accompanying physiological processes.

Falling asleep

1st phase - falling asleep. While a person falls asleep, his sensitivity decreases sensory systems and heart rate, consciousness gradually “turns off.” Even the glands begin to work less actively. This can be noticed by burning eyes and dry mouth. The approaching phase of falling asleep can be easily determined by obsessive yawning.

Night owls who stay up late reading or watching TV often notice such sensations. If all the described signs are present, it’s time to give the body a rest. The falling asleep phase is the shortest. It usually lasts about 10 minutes. Then slow-wave sleep begins, which in turn is divided into several stages.

What is slow wave sleep

Slow rest is a rest in which brain activity remains in the low amplitude range. Scientists record this using an EEG (electroencephalogram).

All phases of human sleep take time different durations. If it takes 10 minutes to fall asleep, then the slow-wave sleep phase requires from 80 minutes to 1.5 hours. Duration depends on individual characteristics human physiology, as well as on his rest regime. Unlike REM sleep, the NREM sleep phase is divided into several stages.

Stages

Slow wave (aka slow wave) sleep has the most complex structure. It is divided into the following 3 phases (or cycles):

Light sleep phase

It occurs immediately after falling asleep and lasts about half the time of slow sleep. At this stage, the person’s muscles completely relax, breathing becomes calm and deep. Body temperature drops slightly, slows down heartbeat. The brain completely goes into rest mode.

The EEG records sleep spindles at this time. This is what scientists called theta waves, which form the sigma rhythm (12-14-20 Hz). Such brain activity indicates a complete shutdown of consciousness.

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At this time, the person’s eyes do not move. He is completely relaxed, but not very deeply asleep yet. During easy sleep It's easy to wake a person up. Loud sounds or physical impact can return him to a state of wakefulness.

NREM sleep phase

During this time, brain activity is expressed in the production of delta waves, the frequency of which is 2 Hz. This is the calmest and slowest mode.

It takes about half an hour. During this phase of slow-wave sleep, a person sometimes experiences dreams.

Deep sleep phase

At this time, a person sleeps deeply and soundly. The EEG is dominated by delta wave oscillations with a frequency of 2 Hz. NREM and deep sleep are often combined under the umbrella term delta wave sleep. The duration of the deep sleep phase takes up approximately 15% of the entire night's rest.

Duration and features of the phase deep rest They have been closely studied by specialists for a long time. It was found that at this time the brain actively produces dreams (about 80% of all visions that a person has during the night). Dreams appear in the form of pleasant images or nightmares. Most of them a person forgets when he wakes up.

Even though the deep sleep stage does not take very long, it has a profound effect on the body. For example, in young children suffering from enuresis, involuntary urination may occur at this time. In persons prone to sleepwalking, it is at this stage that attacks of this disease can occur.

REM sleep stage

This phase was discovered not so long ago (in 1953) and is still being comprehensively studied. It was found that the state of quick rest follows immediately after the deep one and lasts about 10-15 minutes.

REM sleep is the time when brain activity is expressed in the production of waves close in frequency to beta waves. Oscillations brain activity during this period they are very intense and fast. Hence the name - “fast”. Also, this period in the scientific literature is called the REM phase, or REM sleep.

A person in this stage is completely motionless. His muscle tone drops sharply, but his brain activity is close to a state of wakefulness. Eyeballs move under closed eyelids.

The connection between vivid, memorable dreams and this phase is the clearest. While staying in it, a person sees the most colorful images and scenes. If awakening is initiated during REM sleep, in 90% of cases the person will be able to retell his visions.

Scientists cannot give a clear answer to the question of how long this sleep phase lasts. Its duration is approximately equal to 20-25% of the total time of night rest. The phase of REM, like slow-wave sleep, has a cyclical structure. The cycles are similar in the nature of brain activity, but differ in duration.

The first cycle occurs approximately 1.5 hours after falling asleep. The time of the next one increases a little and so on. Early morning duration last phase REM sleep can reach several tens of minutes. In this case, the person sleeps shallowly until he finally wakes up completely.

As morning approaches, all systems in the body become active. Begins to work more actively hormonal system. Men have an erection of the penis, women have an erection of the clitoris. Respiration and heart rate changes. Alternate rises and falls in blood pressure alternate.

Waking up in different phases and rest cycles

A person’s general health and well-being directly depend on the quality and duration of night’s rest, which has a heterogeneous structure. Overnight, the human brain needs to go through the stages described. Only under this condition will the body fully recover.

Moreover, all phases are equally important. Slow, fast, deep sleep - they all perform important functions. Having learned what human deep sleep is, scientists have found that it is necessary for normal mental activity and maintaining the skills learned throughout the day. Fast regulates energy resources. Its absence can lead to the death of the body.

What is slow-wave sleep and how long should it last? Delta sleep is one of the phases of night rest, occupying one fifth of it. During this time, all cells are restored, and the brain processes the information accumulated during the day. The significance of this stage is difficult to overestimate, since a person’s physical and intellectual abilities depend on it.

What is deep sleep

On night rest accounts for about a third of a person’s life, 7-8 hours a day. This physiological process promotes recovery of the body and goes through 4 or 5 consecutive cycles of changing fast and slow phases.

The first (also paradoxical) takes up to 15 minutes. The second - orthodox or slow-wave sleep - lasts about an hour and a half, occurs immediately after falling asleep, and has 4 stages. The last one has the greatest effect on the body; the fourth one is deep or delta sleep.

The Importance of Deep Sleep

Why is the delta phase important in the process of night rest? During the day, the brain receives and processes a huge amount of varied information, and its memorization occurs in the delta phase. That is, the effectiveness of training and the level intellectual development directly depend on the quality and duration of deep sleep. In addition to transferring acquired knowledge from short term memory into a long-term great importance have physiological processes.

During scientific research It was found that maximum muscle relaxation is observed in the deep stage. At the same time, catabolism slows down and anabolism – the restoration of body cells – is activated. It removes toxins, other harmful products vital activity, immunity increases.

Thus, a person fully rests during the period of delta sleep. A change in its duration or a failure of the entire cycle leads to chronic fatigue, drowsiness, a weakened immune system, and a decrease in intellectual abilities.

Structure

NREM and REM sleep alternate throughout the night cyclically. Falling asleep begins with the first, orthodox phase. It lasts about an hour and a half and takes place in four successive stages:

• Decreased alpha rhythm on the EEG, appearance of low-amplitude theta rhythms. At this time, the person is in a state of half-asleep, which may be accompanied by the appearance of dream-like hallucinations. Thought processes continue, manifesting as daydreams and reflections on the events of the day. Often there is a solution to pressing problems.
• The electroencephalogram records the predominance of theta waves, as well as the occurrence of characteristic increases in rhythm - “sleep spindles”. At this, the longest, stage, consciousness turns off, the threshold of perception increases, but it is still possible to awaken the sleeping person.
• The appearance of high-amplitude delta waves on the EEG. In the third phase of slow-wave sleep (from 5 to 8% of the total duration) they take up less than half the time. As the delta rhythm predominates, the deepest delta sleep occurs.
• In the fourth phase, which accounts for up to 15% of the night's rest, consciousness is completely turned off, and it becomes difficult to wake up the sleeper. This period accounts for the majority of dreams; at the same time, the likelihood of manifestations of disorders (somnambulism, nightmares) increases.

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Orthodox sleep is replaced by REM sleep, the ratio is approximately 80% and 20%, respectively. In the paradoxical phase, characteristic mobility of the eyeballs is observed; if the sleeper is awakened, he will remember a vivid dream of the sleep phase. The EEG shows electrical activity, close to the waking state. Morning awakening occurs after 4 or 5 complete cycles in the “fast” stage.

Normal duration

What is the norm for deep sleep? Its duration and quality are determined by the individual characteristics of the human body. For one, 4 hours of rest is enough, for another, to get enough sleep, you will need at least 10. The duration is also influenced by the age of the sleeper: in childhood it is up to 9-10 hours, in youth and maturity – about 8, and in old age it is reduced to a quarter of a day. Average perfect time night rest is 7 or 8 hours, and the norm of deep sleep for an adult is determined by the percentage of phases.

If we take 8 hours of sleep as a basis, the duration of the deep period is healthy person will average 20%. That is, in general it will take at least 90 minutes, and each of 4-5 cycles will take 20-25 minutes. When night rest is shortened or increased, the time of each phase decreases or increases accordingly. However, their ratio in percentage terms does not change, and the body recovers fully.

Processes in the body

The electrical activity of the brain is described in the corresponding section on sleep structure. How do all phases manifest themselves physiologically? As you begin to fall asleep, your muscles relax, your blood pressure and temperature drop, and your breathing slows down. In the second period, these indicators increase, but it is still possible to wake a person, despite the partial blackout of consciousness and an increase in the threshold for perception of external stimuli.

The deep phase, which combines the 3rd and 4th stages, is normally characterized by complete muscle relaxation and a slowdown of all metabolic processes. It's hard to wake up, but physical activity indicates the presence of disorders.

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How sleep phases affect human health and what is the secret to good sleep

Reasons for violations

Sometimes life circumstances require reducing the time of deep sleep (exam session or time pressure at work). A short-term increase in physical activity or mental activity is quickly compensated for. But if the duration of this phase decreases over time, chronic fatigue appears, memory deteriorates, and somatic diseases develop.

The reasons may be:

• psycho-emotional overload, stress;
• diseases of internal organs, nervous or endocrine systems;
• forced awakenings at night (with prostatitis to empty the bladder);
• arterial hypertension.

All of these conditions require treatment medical assistance and treatment, since delta sleep is vital for a person.

How to normalize deep sleep

The deep sleep phase should be at least 20% of the total amount. If you have chronic feelings of lack of sleep, weakness and fatigue, it’s time to think about increasing your total time sleep. It is important to follow a routine, try to stick to the chosen time for falling asleep and waking up. Physical activity during the day and a calm atmosphere in the evening, combined with a light dinner, also help normalize sleep.

2013-03-05 | Updated: 2018-05-29© Stylebody

Scientists have long proven that good sleep, which includes two main phases - slow and fast - is extremely important for human health and well-being. And this fact must be taken into account when creating a daily routine. There is an old folk saying, which claims that “the morning is wiser than the evening.” And indeed, to accept important and complex solutions It's much easier in the morning than at night. In addition, each of us has noticed how lack of sleep affects well-being and performance. A sleepless night may entail not only a sharp decline mental activity, but also headache, weakness, weakness and other unpleasant symptoms.

Physiology of sleep

The human body is designed in such a way that all processes occurring in it are tied to a certain daily time and largely depend on the change of day and night. Sleep and wakefulness constantly alternate between each other and occur at approximately the same time. And if the normal sleep-wake rhythm is suddenly disrupted, this has the most negative impact on work various systems and human organs. From chronic lack of sleep First of all, the nervous and immune system, which can lead to the gradual disabling of the entire organism.

Wakefulness and sleep are two opposite and, at the same time, interconnected states. When a person does not sleep, he actively interacts with the environment: he eats, exchanges information, and so on. During sleep, on the contrary, there is an almost complete disconnection from the outside world, although important processes in the body itself do not stop. It is estimated that sleep and wakefulness are in a 1:3 ratio, and any deviation from this norm is dangerous to health.

Scientists were able to record changes occurring in human brain during sleep, using a research method such as electroencephalography. It allows you to make a graphic recording in the form of waves, the decoding of which provides information about the quality of sleep and the duration of its different phases. This method is mainly used for diagnosis various violations sleep and to determine their degree negative influence on the body.

When the mechanism that regulates the frequency of sleep and wakefulness is disrupted, various pathological conditions, such as narcolepsy (an irresistible desire to fall asleep that occurs during the day), as well as hypersomnia (an exaggerated need for sleep when a person sleeps much more than normal).

Sleep is characterized by a quality called cyclicity. Moreover, each cycle lasts an hour and a half on average and consists of two phases - slow and fast. For a person to get enough sleep, four to five such cycles must pass. It turns out that you need to sleep at least eight hours a day.

The main differences between the phases are:

Duration The predominant phase is the slow phase. It takes up approximately 80% of the time of the entire sleep process and, in turn, is divided into four stages. The fast phase takes significantly less time, and its duration increases in the morning, closer to awakening. Purpose The purpose of sleep phases is different. During the slow phase they are restored internal organs, the body grows and develops. The fast phase is needed to activate and regulate the nervous system, to organize and process accumulated information. During REM sleep, children form the most important mental functions- that’s why in childhood we so often see vivid, memorable dreams.

Brain activity The differences between the slow and fast phases in terms of brain activity are very interesting. If during slow-wave sleep all processes in the brain slow down significantly, then in the REM sleep phase they, on the contrary, are extremely activated. That is, a person is sleeping, and his brain is actively working at this time - that’s why REM sleep is also called paradoxical. Dreams People see dreams throughout the entire cycle, but those dreams that occur during the fast phase are better remembered. The dynamics of dreams also strongly depend on the phase - the slow phase is characterized by restrained dreams, during the fast phase they are more vivid and emotional. Therefore, it is morning dreams that most often remain in memory after waking up.

How does the sleep process proceed?

When a person becomes drowsy and falls asleep, the first stage of non-REM sleep begins, lasting a maximum of ten minutes. Then, as the second, third and fourth stages occur, sleep becomes deeper - all this lasts approximately 1 hour 20 minutes. It is the fourth stage of the first phase that is characterized by such well-known phenomena as sleepwalking, talking in sleep, nightmares, and childhood enuresis.

Then, for a few minutes, there is a return to the third and second stages of slow-wave sleep, after which the fast phase begins, the duration of which in the first cycle does not exceed five minutes. At this point, the first cycle ends and the second cycle begins, in which all phases and stages are repeated in the same sequence. In total, four or five such cycles change per night, and each time the REM sleep phase becomes longer and longer.

In the last cycle, the slow phase may be exceptionally short, while the fast phase is predominant. And it’s not for nothing that nature intended it this way. The fact is that waking up during REM sleep is very easy. But if a person is woken up when slow-wave sleep is in full swing, he will feel exhausted and sleep-deprived for a long time - one can say about him that he “got off on the wrong foot.”

NREM sleep phase (4 stages)

REM sleep phase

When a person enters the REM phase of sleep, it can be seen even from the outside. His eyeballs begin to move actively, his breathing either quickens or slows down, and facial movements may be noticeable. The devices record a slight increase in body and brain temperature, increased cardiovascular activity. During this phase, the process of exchanging information accumulated during wakefulness between consciousness and subconscious occurs, and the energy that the body managed to accumulate during slow sleep is distributed. A person sees colorful dreams that he can remember and retell after he wakes up. Waking up during REM sleep is the easiest and fastest.

How much sleep do you need to get enough sleep?

According to scientists, a person needs to sleep from 8 to 10 hours a day, which equals 4-6 sleep cycles. It should be taken into account that the duration of the sleep cycle is different people is not the same and, depending on the individual characteristics of the nervous system, can vary from 1.5 to 2 hours. And for the body to get proper rest, there should be at least 4-5 such complete cycles. How much sleep a person should have is largely determined by his age.

Here are the approximate sleep norms for different age groups:

• Most long sleep for unborn babies in the mother's womb - about 17 hours a day.
• Newborn babies spend 14 to 16 hours sleeping.
• Babies aged 3 to 11 months need to sleep 12-15 hours.
• One- and two-year-old children sleep 11-14 hours a day.
• It is advisable for preschoolers to sleep at least 10-13 hours.
• The body of primary school children under 13 years of age requires 10 hours of rest at night.
• Teenagers are recommended to sleep between 8 and 10 hours.
• Sleep duration of an adult from 18 to 65 years, depending on personal characteristics body, is 7-9 hours.
• The need of people after 65 years decreases slightly - they need to sleep from 7 to 8 hours.

How to sleep less and get enough sleep

The quality of sleep is very dependent on what time a person goes to bed. Sleeping until midnight from 19.00 to 24.00 is extremely beneficial. People who are accustomed to falling asleep early feel refreshed and well-rested, even if they get up at dawn. In this case, a person can sleep less, but still get enough sleep. And the trick is that the value of sleep in a certain period of time is different.

Sleep value table by hour

What time is best to get up in the morning?

It is believed that the best time to wake up is from 4 to 6 am. People who rise with the sun are not afraid of fatigue, and they manage to do a lot during the day. But, of course, in order to get up early, you need to develop the habit of going to bed early. Besides, people have different biological rhythms. As you know, people are divided into “night owls” and “larks”. And if a person is a night owl, then it is better for him to wake up around 8-9 in the morning.

How to correctly calculate your wake-up time

It is very difficult to independently calculate the time for which you need to set an alarm clock in order to wake up in the REM sleep phase. As mentioned above, each person's sleep phases have an individual duration. Therefore, before carrying out such calculations, you must first contact medical Center so that specialists can determine your personal sleep rhythm using special instruments.

Although you can calculate the approximate time when it is best to wake up. To do this you need to take average duration slow sleep phase (120 minutes), as well as average duration fast (20 minutes). Then you should count 5 such periods from the moment you go to bed - this is the time you set the alarm clock. For example, if you fell asleep at 23:00, then best time The time for you to wake up will be from 7:20 to 7:40 am. If you decide to sleep longer, for example on Sunday, then the time to get up correctly will be between 09:00 and 09:20.

The importance of sleep for the body

• The main purpose of sleep is to allow the body to rest and recover. Prolonged insomnia is fraught with serious health problems. Animal experiments have shown that complete absence sleep through certain time causes cerebral hemorrhages. People who are chronically sleep deprived soon experience increased fatigue, and then problems with the cardiovascular system join.
• Sleep affects metabolic processes in organism. While a person is in slow-wave sleep, growth hormone is produced, without which protein synthesis cannot occur - therefore, lack of sleep is especially dangerous for children. In people who lack sleep, the cleansing and restoration processes in the body are also disrupted, since during sleep, organ cells are actively supplied with oxygen, and the work of the liver and kidneys, which are responsible for neutralizing and removing harmful substances, is activated.
• During the fast phase, the distribution, processing and assimilation of accumulated information occurs. By the way, as it turned out, you can’t learn or remember anything while you sleep (learning method foreign languages sleeping people did not justify itself), but the information that entered the brain immediately before sleep is actually better remembered.
• REM sleep promotes the activation of all neurohumoral processes - nervous system person tunes in active work. It has been noticed that a lot of nervous diseases appear from lack of sleep.

The effect of sleep on the cardiovascular system

Many of us are accustomed to regularly invigorating ourselves with tonic drinks - strong tea, coffee. Yes, this way you can really cheer yourself up for a short period of time. But then, when caffeine stops working, the person feels even more tired, drowsiness and weakness appear. Therefore, there is nothing better for cheerfulness than normal sleep. People who systematically cut down their sleep time, thereby force their body to work under overload and lead it to exhaustion, as a result of which such problems arise. serious illnesses like ischemia, chronic, and so on.

The effect of sleep on appearance

Medical scientists unanimously claim that lack of sleep provokes oxygen deficiency in the body and inevitably leads to early aging and significant deterioration. appearance. A well-rested person, as a rule, can boast not only of vigor, but also fresh look, good complexion. By the way, metabolic disorders, which can lead to chronic insomnia, often entails increased appetite and. Therefore, athletes and actors, for whom it is vital to always be in good physical fitness, strictly adhere to the sleep-wake schedule.

Sleep and human behavior

It has been noticed that in people who do not get enough sleep, such negative character traits as capriciousness, short temper, irritability, and aggressiveness become more acute. And all because their nervous system is not ready for stress and is constantly on edge. But among those who get good sleep, it prevails great mood and full psychological readiness to overcome life problems. Therefore, if your work involves night shifts, be sure to compensate for the lack of sleep during the day. Drivers should never get enough sleep. A huge number of accidents occurred due to the fact that a sleep-deprived driver was distracted or fell asleep at the wheel.

And finally, we should remember one more function of sleep - through dreams, our subconscious often sends us hints and insights that help us solve important life problems.

The whole dream is divided into two fundamentally various types- This is slow sleep and rapid sleep. In turn, slow-wave sleep is divided into 4 phases. It turns out that there are only 5 different phases of sleep.

slow sleep

It is also called the dormancy stage. It is characterized by thinking and experiencing problems that arise during the day. The brain, by inertia, tries to find a solution to the problems it was working on while awake. A person can see images that implement a solution to a problem.

There is a further decrease in muscle activity, pulse and breathing slow down. The brain gradually stops working. This stage is characterized by short bursts of auditory sensitivity. Several times a minute a person is in a state where it is very easy to wake him up.

Is transitional. The difference between stages three and four of sleep is the number of delta oscillations. But we will not delve into such details.

Characterized by the deepest sleep. It is considered the most important, since at this time the brain receives the most complete rest and restores its performance. In the fourth stage of sleep, it is difficult to wake a person. Cases of talking in a dream or sleepwalking occur precisely in this phase.
The first two phases are considered shallow slow-wave sleep, and the second two are considered deep sleep. NREM sleep is also called orthodox sleep or non-REM sleep.

On the website http://androidnetc.org/category/neobxodimye you can download applications for android. For example, one of the proposed Sleep Time applications will analyze your body vibrations and determine in which phase of sleep you are this moment You are at. When the time of awakening comes, the most appropriate moment for your awakening will be chosen. So many useful applications! Visit the site and see for yourself.

Rapid eye movement sleep (REM sleep)

This stage is also called REM sleep (from the English rapid eye movements, which means “rapid eye movements”). As you may have guessed, REM sleep is characterized by accelerated movements of the eyeballs under closed eyelids - this is the first fundamental difference from slow sleep.

The second difference is that in the REM sleep phase the brain does not rest at all, but on the contrary, it is activated. The heart rate also increases, but the large muscles are completely relaxed.

And the most interesting thing is that in the REM sleep phase it is most difficult to wake a person, although his state is closest to the state of wakefulness. That's why REM sleep is also called paradoxical sleep.
The purpose of REM sleep is not entirely clear. There are several assumptions about this:

1. During the REM sleep stage, the brain sorts out the information received.
2. The brain analyzes conditions environment, in which the organism is located and develops an adaptation strategy. Indirect confirmation of this judgment is the fact that in newborns REM sleep is 50%, in adults - 20-25%, in older people - 15%.

But there is one fact that does not cause controversy - the most vivid dreams come to us in REM sleep! In other stages, dreams are also present, but they are blurred and we remember them very poorly. Scientists also say that you will only remember a dream well if you wake up in the REM phase.

Sequence of sleep stages

Sleep begins with phase 1, which lasts approximately 10 minutes. Then the 2nd, 3rd, and 4th phases follow sequentially. Then in reverse order- 3rd, 2nd and the REM sleep phase begins. Together they form a cycle that repeats 4-5 times a night.

This changes the duration different phases from cycle to cycle. In the first cycle, REM sleep is very short, longer time occupies deep slow-wave sleep. But in the last cycles there may be no deep sleep at all. Typically one cycle is 90-100 minutes.

Now comes the fun part. Your well-being depends on what phase of sleep you wake up in. The worst place to wake up is deep sleep. When you wake up from a deep sleep, you will feel groggy.

It is best to wake up after the end of the REM sleep phase, that is, at the beginning of the first or second phase. Waking up from REM sleep is not recommended.
Now you probably have a question about how to make sure you wake up in the right phase.

I will express only one thought on this matter. As already mentioned, it is quite difficult to wake a person in the deep sleep stage. So if your sleep is interrupted in a natural way, and not the sound of an alarm clock, then you are most likely to wake up in the right phase.

Now a little about the importance of fast and slow sleep. Some scientists say that REM sleep is a relic of the past, supposedly a person does not need it, just like the appendix.

The following facts are cited in support of this statement:

If you forcibly limit the duration of sleep, then the duration of the deep phase of sleep practically does not change; the brain primarily reduces the duration of REM sleep.

But this only proves that deep sleep is more important than fast sleep - no more!

Experiments have been conducted where people were completely deprived of REM sleep for two weeks. However, their health did not deteriorate in any way.

Two weeks is not that long, considering that some people can live that long without sleep at all.

But other scientists conducted experiments on rats. As a result, after 40 days without REM sleep, the rats died.

The sleep process is a very little studied phenomenon. In the future, sleep scientists will have to find answers to many controversial questions.
Well, we need to take care of our sleep and lead healthy image life!