Fast and slow phases of sleep - characteristics and their effects on the human body. NREM and REM sleep: what does it mean and which is better? REM sleep to NREM sleep ratio

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. How long does each stage last, and what value does it bring to the human body, let's try to figure it out.

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 that has different phases, replacing 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 (drowsiness), 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 physical activity a couple of hours;
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 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 wellness, 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. Fast stage much more important, therefore 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. The eyeballs under closed eyelids periodically make rapid movements. 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 fast and slow sleep, then 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 best time for awakening - 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 the next stage for the correct rise 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 full healthy holiday 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? 🙂

A person needs night rest every day. At rest, REM sleep and deep (slow) sleep constantly alternate. Up to five such cycles take place during the night. Scientists have proven that both of these phases are needed for proper rest, and it has already been determined in what period it is better to wake up.

The resting state is divided into stages: slow and fast. Each of them plays an important biological role for the body. Normally, the first takes up about three-quarters of the total time a person spends at rest. At the moment of its onset, a complete movement into the kingdom of Morpheus is noted.

During REM sleep, a person's physiological state changes, and brain activity increases significantly. At this moment, data is exchanged between consciousness and subconscious, information begins to be filtered. Due to this, cognitive abilities improve.

With each new cycle the duration deep dive gets smaller. It is determined that for full recovery The body needs the alternation to be completed before four in the morning. In the future, rest continues, but complete sleep is no longer observed.

Stages of REM and NREM sleep

Highlight next stages slow period:

nap;
sleep spindles;
delta;
deep delta sleep.

The body's functions undergo a number of changes as it enters a state of rest. During the stages of drowsiness and sleep spindles, breathing and thermoregulation slow down, and the person is already dreaming. During complete immersion, they are not remembered, but the pulse quickens and blood pressure increases. There may be nightmares that you cannot remember after waking up. Waking up a person at this moment turns out to be very problematic.

The REM sleep phase is divided into the following stages:

emotional;
unemotional.

They change several times, and the emotional one turns out to be much longer. At this moment, movements of the body and eyes are noted. The brain works the same way as when awake. Waking a person up at this stage is easy. After waking up, he clearly remembers what he dreamed about.

The change of stages occurs through an intermediate state, similar to drowsiness, and not instantly. It takes up about five percent of the time a person spends at rest.

The stages can be recognized by muscle activity. It is noted that it gradually decreases and is practically not observed with complete immersion.

Changes in breathing rate, body temperature and blood pressure are also observed.

What is the difference

Fast and slow periods dreams have a number of differences. Among them are the following:

Features of awakening

There are certain features of awakening at different stages of night's rest. This is due to the fact that each of them differs in the degree of brain activity. It is noted that sleepers will have different sensations after waking up, depending on when they woke up.

Considered unsuitable for lifting deep stage slow sleep During this period, neurochemical processes have not yet had time to fully complete. Due to which the body does not have time to recover and prepare for next day. The result is a feeling of depression and irritability.

During REM sleep it is much easier to wake up. There is a feeling of vigor and fullness of strength. However, it is recommended to get out of bed after this stage is completed, but before drowsiness has already set in. As a rule, this happens in cases where a person wakes up without an alarm clock, but listens to his feelings.

Night rest takes place in stages. Each stage is important for the body. Only if the cycles are completed completely will the morning be easy, and the feeling of fatigue and drowsiness will not appear during the day. A failure in this well-established mechanism leads to the fact that the body does not recover properly and health deteriorates.

All people are different. So, one person will not wake up if you talk loudly next to him, vacuum cleaner or turn on music, while the second one goes into a state of wakefulness after the floor creaks. Light sleep is a state of a person in which he is able to quickly wake up, becoming very irritated. For many people and their close relatives with whom they live in the same apartment, this phenomenon becomes a real problem.

When he is constantly in one of the stages of sleep. There are two of them: fast and slow. Each phase has its own characteristics, which are shown in the table.

slow sleep	REM sleep
First stage: a state of sleep in which new ideas and interesting thoughts can unconsciously arise in a person's subconscious. He is dozing rather than sleeping. A person remains in this state for 5 to 10 minutes.	REM sleep is the fifth stage of sleep. During this period, the state of a sleeping person is as active as possible. But despite this, he remains in one position because his muscles are paralyzed. A person’s subconscious mind works very well, so he remembers all the dreams he had during the fourth stage. That is why, if you wake him up during the fast phase, he will tell you all the dreams in vivid and colorful detail. At this stage it is difficult to wake up. If you want to wake up a person who is in a state of REM sleep, it will be difficult for you to do it, much more difficult than if he was in the fourth stage. In addition, during such a period, a sharp transition to a cheerful state can disrupt the psyche. A person needs about 1 hour for REM sleep.
The second stage: a person’s consciousness completely turns off, he plunges into a full-fledged sleep. But during this phase they worsen auditory analyzers. Therefore, during this period, the mother can wake up if Small child moves in bed, and any person opens his eyes when his name is spoken next to him. 20 minutes is the average duration of this phase.
The third stage is the deeper second stage of sleep.
The fourth stage is characterized by the deepest sleep. It's hard to wake a person, he sees vivid dreams or may suffer from sleepwalking. As a rule, he does not remember any of this, moving into a state of wakefulness. The third and fourth stages last approximately 45 minutes.

When a person goes through all these stages, he completes the first cycle. For proper rest, you need to sleep through five such cycles.

Sleep must be consistent. Ideally, a person should go through each of these stages. This is why all doctors in the world insist that the ideal sleep duration is 8 hours. Don't neglect this rule to maintain your mental health. The phases of human sleep by time, the table describing which is presented above, are needed for the most productive state throughout the day. Professional doctors know what to do if a person wakes up from the slightest noise and therefore cannot go through each stage.

Causes of sensitive sleep

Light sleep time can be beneficial for a person, for example, if he wants to take a light nap without falling into a completely unconscious state. But if such a phenomenon occurs constantly, then oh normal functioning all body systems are out of the question. A person sleeps, but does not get enough sleep, does not go through all stages of sleep in order to fully rest.

The reasons for the appearance of shallow sleep are different. You have no cause for concern if one of these factors applies to you:

You recently became a mother. In this case, light sleep is induced by your body at a physiological level so that you can constantly monitor the state in which your newborn baby is.
Hormonal fluctuations occur in your body. This applies to pregnant women and girls during menstruation.
Your work takes place in night shift. In this case, the body adapts to your schedule;
You are experiencing psychological stress. This may be due to both stress at work and waking up at an earlier, unusual time for you.
If you sleep for 10 instead of the required 8 hours and it becomes a habit, your sleep will become longer, but less quality.
If you are over 50 years old, then a light sleeper can become your constant companion.

All these reasons are either natural or easily eliminated, so if one of them concerns you, do not worry, your health is safe. But it happens that the factors that cause short sleep mean that disturbances have occurred in the body. Such reasons include:

Depression and neuroses. Mental problems can disrupt the subconscious's ability to enter the sleep state.
Somatic illnesses need to be treated as they can cause sleep disorders.
Wrong reception pharmaceuticals or alcohol abuse lead to a person who has drunk alcoholic beverages falling asleep quickly, but this sleep is sensitive and superficial.

Such factors must be avoided, so try to prevent such manifestations.

What to do if you are a light sleeper

Almost every person knows what light sleep means for the body. But this concept should not be confused with insomnia. If you create ideal conditions, a person will wake up rested in case of light sleep. If you cannot get enough sleep in complete silence and darkness, then you are dealing with insomnia.

If light sleep has been bothering you for as long as you can remember, you should consult a doctor. If this phenomenon has recently appeared in your life, then you can try to overcome it yourself.

If you want to know how to deal with light sleep, take a look at the list useful tips and recommendations:

Create the most favorable conditions in the room. To do this, turn off the lights, make sure that the room is quiet, and that you are not too cold or hot.
Lay down clean bedding that will not distract you with too much odor.
Before bed, take a relaxing bath or use the services of a massage therapist.
Avoid drinking drinks that contain caffeine.
Try to pay sufficient quantity time for sports.
Avoid stress at work and at home.

If such measures do not help you, more serious measures should be taken.

Radical measures in the fight against light sleep

If no methods help you and you wake up due to any extraneous factor, even the most insignificant, try the following methods:

Buy sound generator, which is capable of producing white noise. According to psychologists, this sound can not only help a person fall asleep, but also helps you wake up more rested.
Melatonin is a medicine that is recommended for older people who have trouble sleeping. It promotes deeper, longer and more complete rest.
If the above methods are useless, try consulting a psychotherapist. A professional doctor will quickly determine what the problem is and help eliminate it.

And remember, if you have insomnia, then a visit to a somnologist is mandatory.

Sleep problems in a child

If light sleep concerns small child, it is worth taking measures to ensure that the baby sleeps more deeply. But this is normal for infants, but for older children, insufficient rest is fraught with bad consequences.

Do not teach your baby to sleep in absolute silence so that he does not react too aggressively to extraneous noise. In addition, if you are not opposed to sharing holidays, then go to bed with your child together. Usually babies feel much better with their mothers.

How to deal with short sleep in a child over 2 years old

Children over 2 years of age may also have trouble sleeping. Try the following measures:

Check that your child feels well and does not experience any discomfort while in his bed.
Make sure your child follows a daily routine. If he eats, studies, and plays at the same time, then he will fall asleep faster.
White noise is much more effective on children than adults. Use it, and your child will rest better.

It is important that all these methods are performed in combination, then you will see the result very quickly.

How to become a sensitive sleeper

Not always from the ability to fall asleep a short time people want to get rid of it. Sometimes there is a need quick rest during the day, for example, if there is a lot of work to do, but there is no energy left. During short nap the person is charged with a lot of energy and is ready to work further. Here are the basic rules for such a holiday:

Rest should last from 15 to 26 minutes. After it you will wake up rested.
To master this technique, training is required.
You need to fall asleep at the same time.
You should not use modern gadgets before going to bed.

If you are ready to follow these rules, then you can begin to master the technique. Regular training will lead you to success.

Learning to be a sensitive sleeper

To fall asleep, follow the instructions:

Set your alarm and lie down in a position that is comfortable for you.
Concentrate on calming down and turning off all mental processes.
Your brain will understand that it needs to fall asleep, and it will begin to plunge into unconsciousness.

Don't expect to be pleased with the results the first time. It usually takes at least 10 workouts to fall asleep quickly. But after you develop this habit, you will be able to arrange a quick good rest daily.

What should it be like to wake up after REM sleep?

After a light sleep there should be an awakening like this:

You need to get out of bed immediately after you open your eyes.
After waking up, it is forbidden to fall asleep again.
Have a snack, it will help you wake up completely faster.
If possible, go for a brisk walk.

The first few times you may not be able to achieve such an awakening, but do not be discouraged. Don’t give up training, although they may seem difficult to you, then very soon you will be able to take a good rest at any time, without falling out of your habitual routine for an indefinite period.

Human sleep-wake cycle

Even if a person has slept through all the necessary phases, he may feel tired. associated not only with our health, but also with biological factors environment. Body temperature drops at night, which is why we need to rest. If you slept well during the day, then when working on the night shift, your performance will still drop, because temperature regime Will not change.

During the experiment, scientists found that such rhythms always operate, even if a person is deprived of the opportunity to observe the change of day and night. Therefore, try to get enough sleep at night so that during the day your productivity increases to its maximum level. If you cannot do this due to your work schedule, then try to master the technique of sensitive sleep and use it during the night.

Sleep is one of the most amazing states, during which organs - and especially the brain - work in a special mode.

From a physiological point of view, sleep is one of the manifestations of the body’s self-regulation, subordinate to life rhythms, a deep disconnection of a person’s consciousness from external environment, necessary for restoring the activity of nerve cells.

Thanks to good sleep memory is strengthened, concentration is maintained, cells are renewed, toxins are removed and fat cells, stress levels are reduced, the psyche is unloaded, melatonin is produced - the sleep hormone, regulator of circadian rhythms, antioxidant and immune protector.

Sleep duration according to age

Sleep serves as protection against hypertension, obesity, division cancer cells and even damage to tooth enamel. If a person does not sleep for more than 2 days, his metabolism will not only slow down, but hallucinations may also begin. Lack of sleep for 8-10 days drives a person crazy.

IN at different ages people need different quantities hours for sleep:

Unborn children sleep the most in the womb: up to 17 hours a day.

Newborn babies sleep about the same amount: 14-16 hours.
Babies between 3 and 11 months of age require 12 to 15 hours of sleep.
At the age of 1-2 years – 11-14 hours.
Preschoolers (3-5 years old) sleep 10-13 hours.
Primary schoolchildren (6-13 years old) – 9-11 hours.
Teenagers need 8-10 hours of rest at night.
Adults (from 18 to 65 years old) – 7-9 hours.
Elderly people over 65 years old – 7-8 hours.

Old people often suffer from insomnia due to ailments and physical inactivity during the day, so they sleep 5-7 hours, which in turn does not have the best impact on their health.

The value of sleep by hour

The value of sleep also depends on the time you go to bed: you can get enough sleep in an hour like a night or not get enough sleep at all. The table shows the phases of a person’s sleep by time of sleep efficiency:

Time	The value of sleep
19-20 hours	7 o'clock
20-21h.	6 hours
21-22 hours	5 o'clock
22-23 hours	4 hours
23-00 h.	3 hours
00-01h.	2 hours
01-02 hours	1 hour
02-03 hours	30 minutes
03-04 hours	15 minutes
04-05 hours	7 minutes
05-06 hours	1 minute

Our ancestors went to bed and got up according to the sun. Modern man does not lie down before an hour nights, the result is chronic fatigue, hypertension, oncology, neuroses.

With the actual value of sleep at least 8 hours, the body regained strength for the next day.

Some southern cultures have a tradition nap(siesta), and it is noted that the number of cases of stroke and heart attack there is significantly lower.

Features of awakening in each phase of sleep

Sleep is heterogeneous in its structure; it consists of several phases that have their own psychophysiological characteristics. Each phase has specific manifestations brain activity aimed at restoring different departments brain and body organs.

When it is better for a person to wake up according to the phases of sleep, how easy the awakening will be depends on the phase in which his sleep was interrupted.

During deep delta sleep, awakening is the most difficult due to incomplete neurochemical processes that occur during this stage. And here It is quite easy to wake up during REM sleep, despite the fact that during this period the most vivid, memorable and emotional dreams occur.

However constant shortage REM sleep can be detrimental to mental health. It is this phase that is necessary to restore neural connections between consciousness and subconscious.

Phases of sleep in humans

Features of the brain and its changes electromagnetic waves were studied after the invention of the electroencephalograph. An encephalogram clearly shows how changes in brain rhythms reflect the behavior and state of a sleeping person.

The main stages of sleep - slow and fast. They are uneven in duration. During sleep, the phases alternate, forming 4-5 wave-like cycles from 1.5 to less than 2 hours.

Each cycle consists of 4 phases of slow-wave sleep, associated with a gradual decrease in a person’s activity and immersion in sleep, and one of rapid sleep.

NREM sleep predominates in the initial sleep cycles and gradually decreases, while the duration of REM sleep increases in each cycle. The threshold for a person’s awakening changes from cycle to cycle.

Duration of the cycle from the beginning of slow-wave sleep to the end of fast sleep healthy people is about 100 minutes.

Stage 1 is about 10% of sleep,
2nd – about 50%,
3rd 20-25% and REM sleep - the remaining 15-20%.

Slow (deep) sleep

It is difficult to answer unambiguously how long deep sleep should last, because its duration depends on what sleep cycle a person is in, so in cycles 1-3, the duration of the deep sleep phase can be more than an hour, and with each subsequent cycle the duration of deep sleep is greatly reduced.

The phase of slow, or orthodox, sleep is divided into 4 stages: drowsiness, sleep spindles, delta sleep, deep delta sleep.

Signs of slow-wave sleep are loud and rare breathing, less deep than during wakefulness, a general decrease in temperature, a decrease in muscle activity, smooth eye movements that freeze towards the end of the phase.

In this case, dreams are unemotional or absent; long and slow waves occupy an increasing place on the encephalogram.

It was previously believed that the brain rests at this time, but studies of its activity during sleep have refuted this theory.

Stages of slow-wave sleep

In the formation of slow-wave sleep, the leading role is played by such areas of the brain as the hypothalamus, raphe nuclei, nonspecific nuclei of the thalamus and the Moruzzi inhibitory center.

The main characteristic of slow-wave sleep (aka deep sleep) is anabolism: creation of new cells and cellular structures, tissue restoration; it occurs at rest, under the influence of anabolic hormones (steroids, growth hormone, insulin), proteins and amino acids. Anabolism leads to the accumulation of energy in the body as opposed to catabolism, which consumes it.

The anabolic processes of slow sleep begin at stage 2, when the body completely relaxes and recovery processes become possible.

It was noticed, by the way, that active physical labor During the day, it prolongs the deep sleep phase.

The onset of falling asleep is regulated by circadian rhythms, and they, in turn, depend on natural light. The approach of darkness serves as a biological signal to reduce daytime activity, and the time for rest begins.

Sleepiness itself precedes falling asleep: a decrease motor activity and level of consciousness, dry mucous membranes, sticking eyelids, yawning, absent-mindedness, decreased sensitivity of the senses, slow heart rate, an irresistible desire to lie down, momentary lapses into sleep. This is how the active production of melatonin manifests itself in the pineal gland.

At this stage, the rhythms of the brain change insignificantly and you can return to wakefulness in a matter of seconds. Subsequent stages of deep sleep demonstrate an increasing loss of consciousness.

Napping, or Non-REM(REM - from English rapid eye movement) - the 1st stage of falling asleep with half-asleep dreams and dream-like visions. Slow eye movements begin, body temperature decreases, heart rate slows down, and on the brain encephalogram, alpha rhythms that accompany wakefulness are replaced by theta rhythms (4-7 Hz), which indicate mental relaxation. In this state, a person often comes to a solution to a problem that he could not find during the day. A person can be brought out of slumber quite easily.
Sleepy spindles – medium depth when consciousness begins to turn off, but the reaction to calling your child’s name or crying remains. The sleeper's body temperature and pulse rate decrease, muscle activity decreases; against the background of theta rhythms, the encephalogram reflects the appearance of sigma rhythms (these are altered alpha rhythms with a frequency of 12-18 Hz). Graphically, they resemble spindles; with each phase they appear less frequently, become wider in amplitude, and fade away.
Delta– without dreams, in which the brain encephalogram shows deep and slow delta waves with a frequency of 1-3 Hz and a gradually decreasing number of spindles. The pulse quickens slightly, the breathing rate increases with a small depth, and decreases blood pressure, eye movements slow down even more. There is a blood flow to the muscles and active production of growth hormone, which indicates the restoration of energy costs.
Deep delta sleep- complete immersion of a person into sleep. The phase is characterized by a complete shutdown of consciousness and a slowdown in the rhythm of delta wave oscillations on the encephalogram (less than 1 Hz). There is even no sensitivity to smells. The sleeping person's breathing is rare, irregular and shallow, and there is almost no movement of the eyeballs. This is a phase during which it is very difficult to wake a person. At the same time, he wakes up broken, poorly oriented in the environment and does not remember dreams. It is extremely rare in this phase that a person experiences nightmares, but they do not leave an emotional trace. The last two phases are often combined into one, and together they take 30-40 minutes. The usefulness of this stage of sleep affects the ability to remember information.

Stages of REM sleep

From the 4th stage of sleep, the sleeper briefly returns to the 2nd stage, and then the state of rapid eye movement sleep (REM sleep, or REM sleep) begins. In each subsequent cycle, the duration of REM sleep increases from 15 minutes to an hour, while sleep becomes less and less deep and the person approaches the threshold of awakening.

This phase is also called paradoxical, and here's why. The encephalogram again records fast alpha waves with low amplitude, as during wakefulness, but the neurons spinal cord are completely switched off to prevent any movement: the human body becomes as relaxed as possible, muscle tone drops to zero, this is especially noticeable in the mouth and neck area.

Motor activity manifests itself only in the appearance of rapid eye movements(REM), during the period of REM sleep a person clearly notices the movement of the pupils under the eyelids, in addition, body temperature rises, activity intensifies of cardio-vascular system and adrenal cortex. Brain temperature also rises and may even slightly exceed its waking level. Breathing becomes either fast or slow, depending on the plot of the dream that the sleeper sees.

Dreams are usually vivid, with meaning and elements of fantasy. If a person is awakened in this phase of sleep, he will be able to remember and tell in detail what he dreamed.

People who are blind from birth do not have REM sleep, and their dreams consist not of visual, but of auditory and tactile sensations.

In this phase, the information received during the day is adjusted between the conscious and subconscious, and the process of distributing the energy accumulated in the slow, anabolic phase takes place.

Experiments on mice confirm that REM sleep is much more important than non-REM sleep. That is why awakening in this phase artificially is unfavorable.

Sequence of sleep stages

The sequence of sleep stages is the same in healthy adults. However, age and various sleep disorders can fundamentally change the picture.

Newborn sleep, for example, consists of more than 50% REM sleep., only by the age of 5 the duration and sequence of stages becomes the same as in adults, and remains in this form until old age.

In older years, the duration of the rapid phase decreases to 17-18%, and the phases of delta sleep may disappear: this is how age-related insomnia manifests itself.

There are people who, as a result of a head or spinal cord injury, cannot sleep fully (their sleep is similar to light and brief oblivion or half-asleep without dreams) or go without sleep at all.

Some people experience numerous and prolonged awakenings, due to which a person is completely sure that he did not sleep a wink during the night. Moreover, each of them can wake up not only during the REM sleep phase.

Narcolepsy and apnia are diseases that demonstrate atypical progression of sleep stages.

In the case of narcolepsy, the patient suddenly enters the REM phase and can fall asleep anywhere and at any time, which can be fatal for him and those around him.

Apnia is characterized by sudden stop breathing in sleep. Among the reasons are a delay in the respiratory impulse coming from the brain to the diaphragm, or excessive relaxation of the muscles of the larynx. A decrease in the level of oxygen in the blood provokes a sharp release of hormones into the blood, and this forces the sleeper to wake up.

There can be up to 100 such attacks per night, and they are not always recognized by the person, but in general the patient does not receive proper rest due to the absence or insufficiency of certain phases of sleep.

If you have apnea, it is very dangerous to use sleeping pills; they can cause death from sleep apnea.

Also, the duration and sequence of sleep stages can be influenced by emotional predisposition. People with “thin skin” and those who are temporarily experiencing difficulties in life have an extended REM phase. And in manic states, the REM stage is reduced to 15-20 minutes throughout the night.

Rules for healthy sleep

Adequate sleep is health strong nerves, good immunity and an optimistic outlook on life. You should not think that time passes in a dream uselessly. Lack of sleep can not only have a detrimental effect on your health, but also cause tragedy..

There are several rules healthy sleep that provide deep sleep at night and, as a result, excellent health and high performance during the day:

Stick to a bedtime and wake-up schedule. It is best to go to bed no later than 11 pm, and all sleep should take at least 8, ideally 9 hours.
Sleep must necessarily cover the period from midnight to five in the morning, during these hours it produces maximum amount melatonin – the hormone of longevity.
You should not eat food 2 hours before bedtime, V as a last resort, drink a glass of warm milk. It is best to avoid alcohol and caffeine in the evening.
An evening walk will help you fall asleep faster.
If you have difficulty falling asleep, it is advisable to take a warm bath before bed with an infusion of soothing herbs (motherwort, oregano, chamomile, lemon balm) and sea salt.
Be sure to ventilate the room before going to bed. You can sleep with the window slightly open and the door closed, or open the window in the next room (or in the kitchen) and the door. To avoid catching a cold, it is better to sleep in socks. The temperature in the bedroom should not fall below +18 C.
It is healthier to sleep on a flat and hard surface, and use a bolster instead of a pillow.
Stomach position is the worst position for sleeping, the position on your back is most beneficial.
After waking up, a small exercise stress: exercise or jogging, and, if possible, swimming.