Deep sleep – how long should it last and how does it guarantee good rest
One of the basics of a good rest, without which our body will not be able to regenerate properly, is a deep sleep. Let’s say frankly, that apart from proper diet, it is one of the basics of our existence, that’s why it is so important to provide ourselves with proper conditions for rest. Deep sleep means that we will sleep through the night without any disturbances, insomnia and other disorders will not frighten us, and in the morning we will get up full of energy and desire to act, all-day activity in our private and professional life.
- 1 Sleep – what it actually is
- 2 In what phases does sleep run
- 3 Deep sleep – disorders disturbing its course
- 4 Deep sleep – discomfort caused by its absence
- 5 Deep sleep – how you can guarantee it
Sleep – what it actually is
Before we specify, what we understand by the word “depth” and how long deep sleep should last, we should find out, what actually sleep is. Equally useful may turn out to be the information, in what phases does it run, why is it so important for our health and how serious are the consequences of its deficiency. There are many different definitions of sleep, and most of them are unfortunately fully understandable only for specialists in the field of treatment of its disorders. However, we will try to explain this concept in the most accessible and understandable way for everyone.
Defining the concept of sleep, we can say that it is one of the biological needs ofour body, without which we are not able to function normally. It is a physiological state, occurring cyclically each day, during which the central nervous system passes into the so-called resting state. The organism can at any time go back to the state of consciousness and in this way we distinguish sleep from unconsciousness or coma.
Symptoms indicating that we are asleep are:
- a reduced response to external stimuli;
- a decrease in bioelectrical activity of the brain;
- decreased skeletal muscle tone;
- Lack of conscious contact with the environment;
- involuntary eye movements;
- lack of motor activity, and the body assumes a characteristic posture that allows full rest.
In what phases does sleep run
Many people misinterpret sleep as dreams, which, admittedly, are often its part, but in fact it is a complex process divided into several stages. These are the phases of sleep that run consecutively throughout the night and a normal sleep, in which there are no disturbances, we can divide into two consecutive phases:
1. NREM (Non-Rapid Eye Movement)
This is the first phase of sleep, also called slow-wave sleep, into which the body passes immediately after falling asleep, and also the longest, because it lasts about 80 – 100 minutes for one cycle, repeating four to five times a night. Its characteristic feature, from which the name comes, is the complete lack of eye movements, or they move in a practically imperceptible way. This is a deep sleep and it is during this phase that the body begins to regenerate, releasing into the blood the necessary hormones and other substances. In this phase of sleep we can distinguish four separate stages:
- stage 1, the shallowest, during which gradually decreases the sensation of external stimuli, muscle tension, the body calms down, theta waves appear in the brain. In this phase, however, we are not yet fully asleep, and it is easy to awaken us from it;
- stage2, which also cannot yet be called real sleep, although any movement of the eyeballs ceases and we do not react to stimuli, but we are still prone to rapid awakening;
- stage 3, when we fall into deeper and deeper sleep, which is also signalled by the work of our brain, in which delta waves appear, there is a drop in body temperature, blood pressure and heart rate;
- stage 4, which is exactly deep sleep. In the brain delta waves completely dominate, eyeballs do not move, but there are involuntary body movements. In this phase of sleep first dreams appear, which are a prelude to the REM phase.
2. REM (Rapid Eye Movement)
As its name suggests, combined with involuntary , rapid movements of the eyeballs. It is also much shorter than the NREM phase, lasting only 5 to 30 minutes per cycle. Another name for the REM phase, which can be encountered, is paradoxical sleep, also does not have its division into separate stages, occurs alternately with the NREM phase, changing with it on average every mentioned 80 – 100 minutes, several times a night. In the REM phase, brain activity, heart rate, blood pressure increase, and dreams appear. At the same time, the whole body undergoes a relaxation, called sleep paralysis, which occurs in order to protect us from the possible negative consequences of violent movements.
Studies, carried out by specialists in the treatment of sleep disorders, have clearly demonstrated the importance of this phase for human health, affecting, among other things:
- the maintenance of mental well-being;
- the proper functioning of the brain and the nervous system;
- mental abilities, especially the ability to remember and learn.
Deep sleep – disorders disturbing its course
Let’s say frankly, that without a few hours of quiet, deep sleep, most of us are not able to function properly the next day. We feel sleepy, we often don’t have strength or desire to perform even the simplest activities. Unfortunately, our rest, or simply a deep sleep, which we need after many hours of daily activity, is disturbed by various disorders that prevent us from sleeping, such as:
To which we include disorders consisting primarily in the occurrence of disturbing symptoms during them, which are:
- involuntary body movements;
- sleepwalking, or somnambulism, or walking around the apartment while remaining in the NREM phase of sleep;
- night terrors, especially in children, who wake abruptly and are accompanied by crying or screaming;
- nightmares, occurring during the REM phase, when we wake up with a feeling of terror caused by the dream, occurring several times during the night;
- sleep paralysis, occurring just after waking up, manifested by difficulty in speaking and moving, lasting from a few seconds to as long as a few tens of minutes.
There are many causes of parasomnias, and as the most common is mentioned stress, a social disease that has a negative impact on virtually every part of our body, which, if untreated, can completely ruin our health.
Another large group of sleep disorders including, above all, difficulties with falling asleep or waking up. These disorders occur either at the end or the beginning of sleep and we divide them into two main groups:
- internal, consisting of disturbances in the daily rhythm of sleep and wakefulness, disruption of our internal biological clock making it difficult for us to fall asleep and have a proper rest;
- external, manifested primarily by insomnia, a difficult to treat disease with a variety of causes. Other, equally troublesome symptoms include sleep apnea, or snoring. We can also encounter narcolepsy, a neuropsychiatric disease whose symptoms include excessive sleepiness and falling asleep several times a day, independent of the patient’s will.
Deep sleep – discomfort caused by its absence
Diseases causing disorders of both phases of sleep, especially NREM responsible for this essential deep sleep are many. Its lack has an immediate negative impact on our health, and may itself become the cause of numerous ailments, and by not getting enough sleep we soon start complaining about problems with:
- disorders of cognitive functions, resulting from fatigue affecting the work of the brain, so that our memory, concentration, learning ability and logical thinking suffer. There may also be problems with speaking;
- weight gain, and few people realize that lack of sleep is one of the causes of overweight and obesity, resulting from disorders in the secretion of hormones responsible for our appetite. The level of ghrelin increases, causing more frequent snacking, reaching for extremely fattening, high-calorie snacks, and lack of sleep also contributes to the development of type 2 diabetes;
- a feeling of fatigue, caused by a lack of regeneration of the body at night;
- lower immunity of the body, which is strengthened by undisturbed deep sleep, and a weakened one opens the way for inflammations, infections and more serious diseases. It is responsible, among other things, for the decreasing level of natural melatonin, a hormone produced in the pineal gland of the brain only at night, in the absence of light;
- greater susceptibility to stress, which destroys the whole health, has a negative impact on our physical and mental condition, the symptoms of which are growing problems with falling asleep leading in consequence to insomnia;
- risk of getting neurodegenerative diseases, especially Alzheimera disease, in elderly people symptoms of dementia may also intensify;
- sight disorders, manifesting themselves in various ways, and these may include a feeling of tiredness, burning eyelids turning into pain, increasing bruises under the eyes, and even double vision, glaucoma, photophobia, and particularly dangerous swelling of the optic nerve, the cause of which is an increase in intracranial pressure, also causing severe headaches;
- improper functioning of the digestive system, weakening of intestinal work, reduction in the number of bacteria building a healthy intestinal microflora, which with further neglect of the quality and hygiene of sleep leads to inflammation, and even diseases such as inflammatory bowel disease or Crohn’s syndrome;
- diseases of the heart and the entire cardiovascular system, an increased risk of myocardial infarction, stroke and a health-threatening increase in blood pressure.
Deep sleep – how you can guarantee it
Taking into account the number of diseases that can be caused by chronic lack of sleep, it is better to spare ourselves and if we belong to the group of people who have problems with sleep, we should take care to provide ourselves with proper conditions for regenerative rest. Our organism to maintain health and full mental and physical efficiency needs from 7 to 9 hours of sleep per night, however we rarely manage to sleep that much.
The NREM phase, or deep sleep, takes up only about 20% of the time we spend sleeping, so it can be disturbed by many factors, of which we are sometimes guilty. So if we want to finally get some sleep, taking care of our daily sleep hygiene, we need to remember about:
Going to bed at the same time
An integral part of a regular lifestyle that is definitely worth living. Going to bed and getting up at the same time should become a habit, as should not taking a nap during the day, which can disrupt our daily rhythm.
The right diet is not only important in the fight against obesity, it also has a significant impact on how we sleep. Properly selected diet is at least half of the success in the fight against sleep disorders, and the principles that should be followed when choosing the evening menu are:
- eating products with a low glycemic index, less protein and more carbohydrates, which are provided by dark, whole grain bread, brown rice, groats and fruit;
- eliminate foods that are hard to digest, full of fat, and spicy;
- ensuring the right amount of nutrients that make it easier to fall asleep and regenerate the body, including melatonin and Omega – 3 fatty acids, which have a beneficial effect on the work of the nervous system;
- not eating the last meal too late, the optimum time is 2 – 3 hours before going to bed so that the body has time to digest dinner;
- not drinking large amounts of liquids before bedtime, which can cause overfilling of the bladder and the need to get up at night to go to the toilet;
- avoiding alcohol, after which we will not be able to sleep, and other stimulants, black tea and coffee;
- using dietary supplements to supplement the lack of natural melatonin, to get rid of problems with falling asleep once and for all, and to guarantee a strong sleep, such as Melatolin Plus.
A large dose of exercise in the fresh air not only promotes better condition. Physical activity also makes it easier to fall asleep, causes greater fatigue, discharge of excess energy and adrenaline accumulated during the day. A tired man usually falls asleep quickly and sleeps soundly, fully regenerating his body. Of course, no one is talking about exhausting, long hours of exercise, because the effect can be the opposite, but a long evening walk is highly recommended.
A comfortable bed and mattress
The basis of good rest, of course, is a comfortable bed and ergonomic mattress, absolutely suited to the body, giving it the right support points, of the most suitable hardness. Lying on it should give relaxation, especially to the spine, make us get up in the morning rested and without any ailments. Similar rules should apply to the selection of bedding, made only of natural, breathable materials, which should be changed once a week.
Bedroom temperature and lighting
The temperature in the bedroom is another issue guaranteeing a deep sleep, which cannot be omitted and should preferably not exceed 18 – 20 degrees. You should also avoid harsh light before going to bed, instead of browsing the Internet on a laptop or tablet, it is better to read a book, give your tired eyes a rest, thanks to which they will not be red and swollen in the morning.