Ratio of fast and slow sleep. Sleep phases. Norm and pathology. Age-related changes in sleep. Comparative description of the phases of fast and slow sleep How fast sleep differs from slow sleep briefly

Content

People have always been interested in the nature of sleep, because a person devotes a third of his life to this physiological state. This is a cyclical phenomenon. During 7-8 hours of rest, 4-5 cycles pass, including two phases of sleep: fast and slow, each of which can be calculated. Let’s try to figure out how long each stage lasts and what value it brings to the human body.

What are sleep phases

For many centuries, researchers have been studying the physiology of sleep. In the last century, scientists were able to record bioelectrical oscillations that occur in the cerebral cortex during sleep. They learned that this is a cyclical process with different phases that follow each other. An electroencephalogram is taken using special sensors attached to a person’s head. When the subject is sleeping, the devices first record slow oscillations, which subsequently become frequent, then slow down again: there is a change in the phases of the dream: fast and slow.

Fast phase

Sleep cycles follow one after another. During the night's rest, the fast phase follows the slow phase. At this time, heart rate and body temperature increase, the eyeballs move sharply and quickly, and breathing becomes frequent. The brain works very actively, so a person sees a lot of dreams. REM sleep activates everyone's work internal organs, relaxes muscles. If a person is woken up, he will be able to tell the dream in detail, because during this period the brain processes the information received during the day, and an exchange occurs between the subconscious and consciousness.

Slow phase

Fluctuations in the slow rhythm electroencephalogram are divided into 3 stages:

Nap. Breathing and other reactions slow down, consciousness floats away, different images appear, but the person still reacts to the surrounding reality. At this stage, solutions to problems often come, insights and ideas appear.
Shallow sleep. There is a blackout of consciousness. Heart rate and body temperature decrease. During this period, the dreamer is easy to wake up.
Deep dream. At this stage, it is difficult to wake a person. The body actively produces growth hormone, regulates the functioning of internal organs, and tissue regeneration occurs. At this stage, a person may experience nightmares.

Sequence of sleep phases

In a healthy adult, the stages of dreaming always occur in the same sequence: 1 slow phase(nap), then 2,3 and 4, then reverse order, 4, 3 and 2, and then REM sleep. Together they form one cycle, repeating 4-5 times in one night. The duration of the two dream stages may vary. In the first cycle, the deep sleep phase is very short, and last stage it may not exist at all. The sequence and duration of stages can be influenced by the emotional factor.

Deep dream

Unlike REM sleep, the deep phase has a longer duration. It is also called orthodox or slow wave. Scientists suggest that this condition is responsible for restoring energy expenditure and strengthening the body's defense functions. Research has shown that the onset of the slow wave phase divides the brain into active and passive areas.

In the absence of dreams, the areas responsible for conscious actions, perception, and thinking are switched off. Although during the deep phase heartbeat and brain activity decrease, catabolism slows down, but memory replays already learned actions, as evidenced by external signs:

twitching of limbs;
special breathing order;
playing different sounds.

Duration

Each person has an individual norm of delta sleep (deep phase). Some people need 4 hours of rest, while others need 10 to feel normal. In an adult, the deep phase takes up 75 to 80% of all sleep time. With the onset of old age, this duration decreases. The less delta sleep, the faster the body aging. To increase its duration, you must:

create a more effective wake/rest schedule;
before a night's rest, give the body a couple of hours physical activity;
do not drink coffee, alcohol, energy drinks, do not smoke or overeat shortly before the end of wakefulness;
sleep in a ventilated room in the absence of light and extraneous sounds.

Stages

The structure of sleep in the deep phase is heterogeneous and consists of four non-rem phases:

The first episode involves memorizing and understanding the difficulties that occurred during the day. At the stage of drowsiness, the brain seeks solutions to problems that arose during wakefulness.
The second phase is also called “sleep spindles.” Muscle movements, breathing and heart rate slow down. Brain activity gradually fades, but there may be brief moments of particularly acute hearing.
Delta sleep, in which the superficial stage changes to a very deep one. Lasts only 10-15 minutes.
Strong deep delta sleep. It is considered the most significant because throughout the entire period the brain reconstructs the ability to work. The fourth phase is distinguished by the fact that it is very difficult to wake up a sleeping person.

REM sleep

REM (rapid eye movement) - the phase or from the English rem-sleep is distinguished by the increased work of the cerebral hemispheres. The biggest difference is the rapid rotation of the eyeballs. Other characteristics fast phase:

continuous movement of organs visual system;
vivid dreams are brightly colored and filled with movement;
independent awakening is favorable, gives good health and energy;
Body temperature rises due to vigorous metabolism and strong blood flow.

Duration

After falling asleep a person most spends time in the slow phase, and REM sleep lasts from 5 to 10 minutes. In the morning the ratio of stages changes. The periods of deep breathing become longer, and deep periods become shorter, after which the person wakes up. The rapid stage is much more important, so if it is interrupted artificially, it will adversely affect emotional state. The person will be drowsy throughout the day.

Stages

The fast phase, also called paradoxical dream, is the fifth stage of dreaming. Although the person is completely immobile due to complete absence muscle activity, the state resembles wakefulness. Eyeballs periodically make quick movements under closed eyelids. From stage 4 of slow-wave sleep, a person returns to the second, after which the REM phase begins, which ends the cycle.

The value of sleep by hour - table

It is impossible to say exactly how much sleep a person needs. This indicator depends on individual characteristics, age, sleep disturbance and daily routine. A baby may need 10 hours to restore the body, and a schoolchild – 7. The average duration of sleep, according to experts, varies from 8 to 10 hours. When a person correctly alternates between fast and slow-wave sleep, even in a short period every cell in the body is restored. The optimal time for rest is before midnight. Let's look at sleep efficiency by hour in the table:

Beginning of sleep	The value of rest

Best time to wake up

If you look at the dream value table, you can see that the time from 4 to 6 in the morning brings less benefits for rest. This period is the best for awakening. At this time, the sun rises, the body is filled with energy, the mind is as clean and clear as possible. If you constantly wake up with the dawn, then fatigue and illness will not be a problem, and you can do much more in a day than after waking up late.

What phase is best to wake up in?

The physiology of sleep is such that all stages of rest are important to a person. It is advisable that 4-5 complete cycles of 1.5-2 hours pass per night. The best time to get up varies from person to person. For example, it is better for owls to wake up between 8 and 10 am, and larks get up at 5-6 am. As for the dream stage, everything is ambiguous here too. From the point of view of the structure and classification of phases, the best time to wake up is those couple of minutes that occur at the end of one cycle and the beginning of another.

How to wake up during REM sleep

As the cycles repeat and the duration of the slow phase increases to 70% of the night's rest, it is desirable to catch the end of the REM stage to awaken. It is difficult to calculate this time, but to make your life easier, it is advisable to find the motivation to get up early in the morning. To do this, you need to learn, immediately after waking up, not to lie idle in bed, but to spend breathing exercises. It will saturate the brain with oxygen, activate metabolism, and give a charge of positive energy for the whole day.

How to calculate sleep phases

Self-calculation is difficult. You can find circadian rhythm calculators on the Internet, but this method also has a drawback. This innovation is based on average indicators and does not take into account the individual characteristics of the body. Most reliable method calculation - contact specialized centers and laboratories, where doctors, by connecting devices to the head, will determine accurate data on signals and oscillations of the brain.

You can independently calculate the stages of a person’s sleep something like this. Duration (average) slow stage– 120 minutes, and fast – 20 minutes. From the moment you go to bed, count 3-4 such periods and set the alarm clock so that the time you get up falls within a given period of time. If you go to bed at the beginning of the night, for example at 22:00, then safely plan to wake up between 04:40 and 05:00. If this is too early for you, then next stage for proper ascent will be in the time interval from 07:00 to 07:20.

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Attention! The information presented in the article is for informational purposes only. The materials of the article do not call for self-treatment. Only qualified doctor can make a diagnosis and give treatment recommendations based on the individual characteristics of a particular patient.

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Hello, dear blog readers! I don’t know about you, but I have always been interested in the topic of sleep. I’ve heard a lot of all sorts of theories and guesses about it: about slow-wave sleep, and about fast sleep, and about all its various phases. But I’ve never “tested” this myself. I heard, and that's all. But I just didn’t have enough brains to dig deeper 🙂 (although I already wrote an article about healthy sleep before, which means I did a little digging).

So today I decided to improve and fill this gap in knowledge. Well, as usual, everyone interesting information What I find on the Internet, I openly share with you.

Classification of stages

So, the first thing I came across was the most simplest classification, known to us since school. According to it, the stages of sleep are divided into:

fast ;
and slow.

Moreover, each stage has its own “substages”. So, fast sleep is divided into:

emotional;
unemotional.

A slow on the:

nap;
sleep spindles;
delta sleep;
deep delta sleep.

I don’t see the point in going deeper into each of these points - there is little interesting there (mainly the difference in brain wave activity and all that). Better take a look at this table of differences between the stages that I compiled for you:

Well, now let's determine what happens to us when we fall asleep and how all these stages alternate with each other. Now this is a little more interesting, isn’t it?

Sequence of stages

1) After we got into bed and started to fall asleep, it activates first stage of sleep(or the drowsiness stage).

It lasts about 5-10 minutes, no more. As a rule, in this short period of time our brain does not have time to “calm down” and is still quite active: it solves the latest tasks, problems - in general, it works by inertia :)

2) Then follows second stage of slow-wave sleep.

There is a decrease in muscle activity, slowing of breathing and heart rate. The eyes remain motionless. At this stage there are a number of short moments at which the person is most easily awakened. This stage of sleep lasts about 20 minutes.

3) The third and fourth stages of sleep are very similar to each other and last about 30-45 minutes (the difference is only in the number of delta oscillations - that’s why they are called “delta” and “deep delta” dreams).

4) After this the person returns again into the 2nd stage of slow-wave sleep(described above), and after it goes into the first part of the fast* (very short - only about five minutes).

*Please note that REM sleep occurs only after passing through all 4 (or rather five: 4 forward, and one back :)) phases of slow sleep.

This entire sequence of four points described above is called cycle. The time of the first such cycle is about 90-100 minutes.

What do we do for the remaining 5-6 hours?

It’s simple: the rest of the time these phases are repeated under one condition: the proportion of REM sleep increases by reducing the proportion of slow sleep (in the morning the REM sleep stage can last a whole hour- as it is written in Wikipedia). With proper healthy rest, about five such cycles are observed.

Wow, well, it seems like I explained everything clearly :) Now that we know what is going on and why, let’s try to answer the question: “ When is the best time to wake up? ».

So when is the best time to wake up?

So, I found several ways to determine the best time to rise.

1) Here is this resource. Based on algorithms known only to them, the calculator calculates optimal time for awakening. All you need to do is enter the time you want to fall asleep and click “calculate”.

For example, if I fall asleep at 23:00 (as usually happens), it’s best for me to wake up at 6:00. Who knows, maybe this is true (since I woke up at 6:25 today and waking up was not the easiest - fortunately, a contrast shower helped out) :) Tomorrow I’ll try to get up at 6:00.

2) You can also use this table. I don’t know who its author is, but everything is presented very clearly and intelligibly - many thanks to him for that.

Green The phases of REM sleep are highlighted here, and the slow sleep phases are highlighted in red. And if you believe this scheme, then it is best to wake up at the very end of the first phase - moreover, REM sleep. This time is even marked with an alarm clock.

According to the time scale (x-axis), it is best to wake up seven hours after falling asleep. In principle, everything is the same: if you look at the screenshot above (point 1), then for me, falling asleep at 23:00, it is best to get up at 6:00 - the picture is the same here. That's it, tomorrow I get up exactly at 6:00! If I don’t forget, I’ll write to you about my successes :)

Did you know?

Well, we've sorted out the stages of sleep and determined the best time to wake up. What shall we do now? Oh, I have an idea! Let's find out how animals sleep!

Did you know, What:

cats sleep 16 hours a day;
giraffes, before falling asleep, kneel down and bend their heads around their legs;
dolphins and cetaceans have the ability to sleep unilaterally (this is when one hemisphere of the brain sleeps and the other is awake). Among marine inhabitants, this is explained by the need to surface to gain air during sleep.
Birds can sleep not only while standing, but even on the fly! (migrating birds have developed an interesting mechanism: every 15 minutes one individual flies into the very center of the flock and falls asleep, only slightly working its wings. It hovers in the air mainly due to the air flow of the flock. After a kind of rest, it returns, giving way to others) .

Agree that in our case everything is not so bad - when there is a soft bed, a blanket and a pillow under your head :)

Let's summarize

Well, I think I told you everything I wanted to talk about. I hope the article was not too confusing, although sleep phases are a rather complicated thing.

That's all. Good luck to you, dear readers, and all the best. Take care of your health, both physical and mental, and do not forget to visit my blog pages.

To be honest, I still don't understand the intention of the author of this video. Well, why, why wake up a sleeping tit, and in this way too? 🙂

Every night we all go through phases of sleep: rapid and slow sleep. Physiologically, sleep is a complex various processes, during which we can experience several cycles of these two phases.

For a long time it was believed that there was no way to study a person’s dreams and their influence on his physiology and psyche in any way. Initially they were studied on the basis of purely physical description processes - it was possible to determine the sleeper’s pulse, his blood pressure and his body temperature. But about assessing the influence of sleep on mental and physical activity there wasn't even any talk.

With the advent of encephalography in the twentieth century, the possibilities for understanding the processes occurring during sleep have expanded significantly.

Every night's rest is necessary for a person; to some extent we can say that sleep is for a person more important than nutrition. A person deprived of sleep for only two or three days becomes irritable and loses emotional stability, memory lapses begin. Against the background of fatigue and mental retardation due to lack of sleep, a person falls into a depressive state. It is believed that the maximum time a person can live without sleep is 11 days, after which irreversible changes occur in the brain, leading to death.

The main purpose of sleep for the body is to rest all its systems. For this purpose, the body “turns off” all senses and is almost completely immobilized.

Modern science represents sleep as a special period that has behavioral characteristics of the motor sphere and the autonomic nervous system. A feature of sleep is the alternating change of two states with almost opposite manifestations. They are called slow and fast sleep.

The surprising thing is that only together both phases - fast and slow sleep - can restore both the physical and mental strength of the body. By interrupting the night at the stage when only one of the cycles will be implemented, good rest the body will not receive it. The combination of fast and slow sleep renews the brain's performance and fully processes the information received during the past day. It is the complete completion of sleep cycles that facilitates the transfer of information from short-term memory to long-term memory.

Actually good sleep and is the final stage in solving the problems of the past day and a kind of “summing up” of its results.

Also, complete and proper rest during sleep improves the health of the whole body.

The following physiological processes occur only during night rest:

fluid balance is restored and the body is cleansed by removing excess moisture;
collagen protein is synthesized, which plays an important role in strengthening joints, blood vessels and skin;
The body absorbs calcium, which is necessary for bone and dental tissue.

These processes are quite lengthy, so for feeling normal You need to sleep about eight hours.

The duration of slow-wave sleep is equal to almost three-quarters of the total time of night rest, its features are as follows:

The slow phase is characterized by a general slowdown in metabolism, a significant decrease in the brain's response to external factors, relaxation of the entire body and general lethargy. Awakening is a very difficult time and leaves discomfort quite long time.

In the slow phase, muscle tissue is regenerated. It is also during this phase that the “reboot” occurs. immune system. Thus, its normal and complete completion is a guarantee of improved well-being.

Slow sleep promotes rehabilitation and healing of the body: cell renewal occurs and the functioning of all body systems improves. REM sleep is different in that it does not have such abilities.

In fact, slow-wave sleep is divided into four components, each of which has various characteristics. Let's look at the components of slow-wave sleep.

A person who falls into a state of drowsiness, despite the decrease in physiological processes, continues to work with the brain and he thinks about and improves some of the most important ideas that he dealt with during the day. The brain receives sufficient quantity oxygen and works with some excess of its capabilities: various options for solving certain situations are searched, optimal options. Often it is during the dozing phase that dreams appear that have positive and pleasant results. The final decisions of some known issues came to humanity precisely during this phase. Mendeleev, Descartes, Bohr and many other scientists admitted that the final processing of their theories occurred precisely during dozing.

Sleepy spindles

This stage is also called the sigma rhythm due to the characteristic impulses observed on the encephalogram. Her distinctive feature is an almost complete blocking of consciousness, similar to that observed during anesthesia. The duration of this stage is half of the entire slow phase. It takes a very long time for the brain to prepare for deep sleep.

Notable is the fact that this activates special cells that separately block the channel of sound transmission to the brain

Delta sleep

A kind of “prelude” to the deep, it happens relatively quickly. During delta sleep, the amplitude of impulses in the brain decreases significantly, the impulses themselves become shorter - brain activity approaches its minimum.

From this stage, which begins about an hour and a half after the start of napping, we are already completely asleep. Brain activity is minimal, there is practically no reaction to any stimuli. It is almost impossible to wake up a person who is in this stage: even loud sounds, braking and quite strong painful sensations unable to interrupt it.

Dreams are present at this stage, but it is almost impossible to remember them - only fragments of images remain in memory. If it is possible to awaken a person during this stage, the rise will be extremely difficult and the body will finally recover to next period sleep may not come.

Another name for this phase is paradoxical or fast wave. There is a significant increase in activity life processes, primarily occurring in the brain. The transition from slow-wave sleep to fast sleep occurs quickly, and serious changes occur throughout the body.

Features of the REM sleep phase include:

Increased breathing and heart rate.
Frequent arrhythmias in the heart.
Decreased muscle tone.
A significant decrease in the activity of the muscles of the neck and diaphragm.
Promotion motor activity eyeballs with closed eyelids.
Clear memories of dreams seen during REM sleep, down to the smallest details, which is completely uncharacteristic of the slow-wave sleep phase.

With each subsequent cycle, the phases of slow and fast sleep alternate, which means that the latter has a longer and longer duration, however, its depth decreases. This happens to make it easier to get out of sleep cycles when you wake up. The prejudice that sleeping better in the morning than at night is wrong. By the third or fourth change of cycles of alternating sleep phases, it is much easier to wake a person.

The REM stage of sleep is unique in its own way. It is in it that the exchange of data takes place between consciousness and subconscious, and what was thought about during dozing again enters consciousness, but now supplemented various options that may happen.

REM sleep is usually divided into two stages: emotional and non-emotional. During the REM sleep phase, they can alternate several times, with the first phase always being slightly longer.

During REM sleep there is a significant change hormonal levels. According to researchers, it is REM sleep that promotes daily readjustment. endocrine system.

Thus, REM sleep seems to sum up all the mental activity of the brain for the entire day. Rest at this stage is necessary for a person so that he can adapt to possible options for the development of yesterday's events.

This is why interrupting this phase sometimes leads to more undesirable consequences than interrupting slow-wave sleep. In this case, we are faced with the problem of not physical, but mental fatigue, leading to possible violations psyche. There is an opinion in the scientific community that if a person is deprived of REM sleep too often, it will undermine his psyche to such an extent that it can lead to death.

For the body, the fast phase is to some extent small stressful situation. The changes taking place in it are quite radical and can lead to some undesirable consequences. For example, most heart attacks, strokes and seizures occur during REM sleep. This is due, first of all, to the fact that the relaxed cardiovascular system is subjected to a sharp and sudden load.

It is impossible to say for sure which of the sleep phases - slow or fast - is better or more important, since each of them performs its own functions. If you try to imagine the entire dream in the form of a curved line, it will look like several “dives” into deep and slow sleep, followed by “ascents” into superficial, fast sleep. The time between such ascents and descents will be approximately one and a half to two hours.

According to physiologists, this one and a half hour time period is the main biorhythm of the human body; it manifests itself not only during rest, but also during wakefulness.

In an adult, the stages of night rest are distributed approximately according to the following ratios:

drowsiness - 12%;
sleep spindles - 38%;
delta sleep - 14%;
deep delta sleep -12%;
REM sleep - 24%.

The first four belong to the phase of slow-wave sleep, the last - to fast sleep. In addition, the phases of sleep are very different and do not replace each other immediately, but over the course of an intermediate state similar to drowsiness. It lasts about 5 minutes.

During the entire sleep period, 5-6 cycles occur full shift all stages. The duration of the stages may vary slightly from cycle to cycle. At the end of the last cycles, the intermediate state is the most sensitive and leads to normal awakening.

Awakening is an individual process and lasts from several tens of seconds to three minutes. At this time, the final recovery occurs normal functions organs and the emergence of clarity of consciousness.

The main differences between NREM and REM sleep

NREM and REM sleep are performed different functions. During each phase human body behaves differently. Often, the behavior of a sleeping person is purely individual, however, there are characteristics that are characteristic of all people, which are presented in the table.

Characteristic		Fast phase
State of the autonomic nervous system	Active work pituitary gland Accelerated synthesis of most hormones	Suppression of reflection spinal cord. The appearance of fast brain rhythms. Increased heart rate. The emergence of a “vegetative storm”
Brain temperature	Decrease by 0.2-0.3°С	Increase of 0.2-0.4°C due to blood flow and increased metabolism
Breathing Features	Loud and deep, there is a lack of rhythm	Uneven, often rapid breathing with delays due to dreams
Eyeball movements	At the beginning of the phase - slow, at the end - almost absent	There is constant rapid movement
Dreams	Dreams are rare; if they exist, they are calm character. It's hard to remember them	Bright and rich pictures and dreams, as a rule, contain a lot of active actions. Well remembered
Awakening	Associated with a depressed state, a feeling of fatigue. Difficulty waking up due to incompleteness chemical processes during the slow phase	Waking up at the beginning of the phase causes mental fatigue. In the end - light and fast, the body wakes up rested. In this case, the state is cheerful, the mood is good

Despite the rather large difference in the nature of the phases of slow and fast sleep, both have a deep physiological, functional and biochemical relationship and are the result of the joint work of the sympathetic and parasympathetic nervous systems.

Regulates slow-wave sleep internal rhythms brain areas and structures, fast contributes to their synchronization and harmonious functioning.

A dream, like all beautiful things, ends sooner or later. The physical and psycho-emotional state of a person depends on at what stage of sleep the awakening occurred.

The most unpleasant thing will be to awaken in the slow phase, when it has entered the deep stage. The best time awakening will be the interval between the end of REM sleep and the end of the first stage of the next cycle. Standing up during the active fast phase is not recommended.

If a person has slept well, then he is full of energy, cheerful and in high spirits. This often happens at the end of the dream.

During this period, his senses are activated, and the person responds well to external irritating factors that contribute to awakening:

Light from the window.
Sounds from the street or music.
Changes in ambient temperature.

If you wake up immediately, you will feel excellent. But, if you skip this time and take a nap a little more, then the body can “delay” into another slow cycle.

We often wake up shortly before the alarm clock. This is not surprising: the body itself adjusts its “ internal clock“under the daily routine and the cycles occur in such a sequence that the fast phase ends at a time close to the moment the artificial clock operates.

If at this moment you tell yourself that such an awakening has occurred ahead of schedule, then you can fall asleep again and wake up in deep stage, ruining your whole next day.

Therefore, the best awakening is the one that happened on its own, without any external factors. It doesn't matter what time it is. If the body symbolizes to us that it has had enough sleep, we cannot be deaf to such a message.

However, in Lately began to appear on sale " smart alarm clocks”, which are connected via wireless sensors to the human body. They read the body parameters and use them to determine the time of awakening - at the end of REM sleep or during the transition from it to an intermediate state.

In any case, even if waking up was easy, do not rush to jump out of bed. The body needs to be given a few minutes to adapt all its systems to the new day. The main thing in this process is not to fall asleep again, think about some idea, get ready for the new day and go ahead!

The phases of human sleep are divided into two types - slow and fast. Their duration is uneven. After falling asleep, the slow phase lasts longer. Before waking up, REM sleep becomes longer.

In this case, the phases alternate, forming wave-like cycles. They last just over an hour and a half. Calculating the phases by the hour will not only make it easy to wake up in the morning and improve the quality of your night's rest, but will also help normalize the functioning of the entire body.

About sleep phases

Sleep is a state in which all organs, especially the brain, work in an unusual mode. At the same time, a person’s consciousness turns off and the restoration of all cells of the body begins. Thanks to a good, full night's rest, toxins are removed from the body, memory is strengthened and the psyche is unloaded.

In order to feel good during the day, your sleep rate should be about eight hours a day. However, this amount may vary depending on the individual characteristics of the human body.

For some, six hours is enough, for others, nine hours is not enough to fully relax and get enough sleep. This difference depends on the lifestyle and age of the person. Night rest is heterogeneous and is divided into two phases - REM and deep sleep.

Slow phase

NREM sleep is also called deep (orthodox) sleep. Immersion in it begins at the beginning of the night's rest. This phase is divided into several stages:

Nap. Usually lasts from five to ten minutes. During this period, the brain is still working, so you can dream. Often there are dreams that are confused with reality, and a person may even find answers to problems that were unresolved during the day.
Falling asleep or sleep spindles. Takes approximately twenty minutes. At this stage, consciousness gradually turns off, but the brain reacts quite sensitively to all stimuli. At such a moment, any noise can wake you up.
Deep dream. This is the time when the body of a healthy person almost ceases to function, and the body relaxes. However, weak impulses still pass through the brain, and sleep spindles are still preserved.

Then comes delta sleep - this is the deepest period. The body relaxes completely and the brain does not react to stimuli. Respiration rate and blood circulation decrease. But the closer to morning, the more the duration of the delta sleep phase decreases.

Interesting ! When falling asleep and waking up, a condition such as sleep paralysis may occur. This condition is characterized by full understanding of what is happening, but the inability to move or say anything. Some people try on purpose.

Fast phase (REM phase)

REM sleep after falling asleep lasts about five minutes. However, with each new cycle, the duration of deep sleep becomes shorter, and the duration of fast sleep increases in time. This phase is already about an hour in the morning. It is during this time period that a person is “easy” to get out of bed.

The fast phase is divided into an emotional period and a non-emotional one. In the first period of time, dreams become pronounced and dynamic.

Phase sequence

The sequence of sleep stages is the same for most adults. This statement is valid for healthy people. REM sleep passes quickly after falling asleep. This phase follows four stages deep sleep. Then follows one turn, which is designated as 4+1. At this time, the brain works intensively, the eyes dart around, and the body is “tuned” to wake up. The phases alternate; there can be up to six of them during the night.

However, age or problems associated with sleep disturbances may change the picture. For example, in young children, more than 50% is the REM phase. Only at the age of 5 years the sequence and duration of the stages become the same as in adults.

In old age, the REM sleep phase is reduced, and delta sleep may disappear altogether. This is how age-related insomnia manifests itself. Some people have head injuries or don't sleep at all. Often they are just dozing. Some people wake up many times during the night, and in the morning they think that they haven’t slept at all. The reasons for this manifestation may be different.

In people with narcolepsy or sleep apnea, nighttime rest is atypical. They get it right away fast stage, they fall asleep in any position and place. Apnea is a sudden stop in breathing during sleep, which is restored after a short period of time.

At the same time, due to a decrease in the amount of oxygen, hormones are released into the blood, which causes the sleeping person to wake up. These attacks can be repeated many times, rest becomes short. Because of this, a person also does not get enough sleep; he is haunted by a sleepy state.

The value of a night's rest by the hour

A person can get enough sleep in one hour or throughout the night. The value of rest depends on the time you go to bed. The following table indicates sleep efficiency:

Time	Value
From 19:00 to 20:00	7 o'clock
From 20:00 to 21:00	6 hours
From 21:00 to 22:00	5 o'clock
From 22:00 to 23:00	4 hours
From 23:00 to 00:00	3 hours
From 00:00 to 01:00	2 hours
From 01:00 to 02:00	1 hour
From 02:00 to 03:00	30 minutes
From 03:00 to 04:00	15 minutes
From 04:00 to 05:00	7 minutes
From 05:00 to 06:00	1 minute

Previously, people went to bed and got up only according to the sun. At the same time, we got a full night's sleep. IN modern world Few people get ready for bed before midnight, which is why fatigue, neuroses and hypertension appear. Lack of sleep is a frequent companion in our lives.

Required duration of rest by age

To rest, a person needs different time, and it depends on age. This data is summarized in the table:

Elderly people often experience certain ailments. Because of them and physical inactivity, they often sleep only five hours. At the same time, in the womb of the mother, the unborn child remains in a state of rest for 17 hours.

How to determine the optimal time to wake up and why calculate sleep phases

Exist special devices that record brain activity. However, in their absence, you can calculate the phase times yourself. NREM sleep takes much longer than REM sleep. If you know how long all the stages are, you can calculate at what stage the brain will work in the morning when a person wakes up.

It is very important to get up during the REM stage of sleep, when we are light sleepers. Then the day will pass joyfully and cheerfully. This explanation is the answer to the question in which phase of sleep a person should wake up.

You can determine this stage yourself only by experiment. You need to approximately calculate the time of REM sleep. Wake up at this time and understand whether it was easy to open your eyes and get up. If yes, then in the future try to wake up at this time. This way you can determine how long a particular person should rest at night.

Important! When conducting the experiment, you should not forget about the time of going to bed. It is of no small importance.

There is a special calculator that determines the online phases of a person’s sleep by time. It is capable of calculating all stages using algorithms. This calculator is quite easy to use. You just need to indicate the hour when the person goes to bed. The program will perform a calculation and show the result at what time people will wake up well rested, that is, how many hours are needed for rest.

Rules for a healthy night's rest

There are several effective rules that will ensure a strong healthy holiday at night and will allow you to achieve high performance and wellness. They are also the answer to a frequently asked question about how to improve sleep quality:

It is advisable to stick to a routine, always fall asleep and get up at the same time.
Sleep should always take place between 00:00 and 05:00. It is during this period that the most melatonin, the sleep hormone, is produced.
You cannot have dinner later than three hours before your night's rest. If you want to eat during the specified interval, it is better to drink a little milk.
Evening walk on fresh air It will not only help you fall asleep faster, but also make your rest complete.
Before going to bed, you can take a bath with herbs (chamomile, lemon balm or motherwort). It will help you calm down and fall asleep faster.
It is necessary to ventilate the room before going to bed.
The recommended sleeping position is on your back or right side; it is not advisable to sleep on your stomach.

By following these recommendations, your sleep quality improves. You also need to do exercises every morning. Run - the best remedy for a cheerful day. However, there is no need to engage in charging “through I can’t.” This leads to overvoltage. It is better then to go in for sports in the afternoon or evening.

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, 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, 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:

Falling asleep.
Slow sleep.
Fast.
Awakening.

Each phase is characterized by a certain duration and accompanying only 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. The duration depends on the individual characteristics of a person’s 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 and heart rate slows down. The brain completely goes into rest mode.

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Duration and characteristics of sleep phases in a child of the first year of life: norms of night and daytime rest for infants

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.

At this time, the person’s eyes do not move. He is completely relaxed, but not very deeply asleep yet. In easy time It is easy to wake a person from sleep. 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.

The duration and features of the deep rest phase 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 condition 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. In the morning, the duration of the last phase of 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

General health and a person’s 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 sleep, rapid sleep, 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 the preservation of skills acquired throughout the day. Fast regulates energy resources. Its absence can lead to the death of the body.