We spend a good third of our lives asleep. But what are the reasons? Why is it not enough for regenerating to lie and rest on the couch? Why do we have to change our state of consciousness in order to remain able to survive?
Sleep is a fascinating topic – linked with many unanswered questions. However, what we know now is that highly complex repair processes take place during sleep. These are indispensable for our physical and psychological well-being. Our body temperature, for example, drops during sleep. Pulse and respiration also calm down. An exception to this is the so-called REM sleep (REM = rapid eye movement). This sleep phase is characterised by rapid eye movements beneath the closed eyelids. The REM sleep phase is the phase of most intense dreaming and the body is paralyzed. Pulse and respiration become more irregular again. Apparently our body is resting. But does it really rest?
To answer this question a short digression into biology is helpful: The pineal gland (epiphysis) is a pea-sized gland in the brain that significantly controls the sleep-wake rhythm through the production of the "sleep hormone" melatonin. The release of melatonin is also dependent on darkness, with light exerting an inhibitory effect in this context. Darkness promotes the production and secretion of melatonin into the bloodstream. This also explains why artificial light disturbs our natural sleep rhythm and should therefore be reduced to a minimum before going to bed. There are also initial indications that melatonin can have a positive effect in the case of certain cancerous diseases. However, further clinical studies are needed to confirm these effects.
Apart from melatonin, a number of other hormones are released during sleep. A well-known hormone is the so-called somatotropin, also known as the growth hormone. It is produced in the pituitary gland. Its concentration rises after falling asleep and reaches its peak during the deep sleep phases. For children and adolescents sufficient sleep is particularly essential since the somatotropin promotes ageappropriate longitudinal growth. In addition, gonadotropin, a hormone that stimulates the gonads, is secreted mostly during puberty and promotes the development of the sex organs.
There are some other hormones that control our metabolic functions at any time of the day or night. Within the scope of this information sheet, however, we have limited ourselves to the most important hormones.
A 24-hour long sleep deprivation affects the body just like about 1.0 per mille alcohol in the blood.
The aforementioned somatotropin is not only responsible for longitudinal growth, but also for a whole range of other metabolic functions. As an anabolic hormone, it has amongst others a positive effect on muscle development. Under certain circumstances (e.g. regular, demanding training and a balanced diet), this can result in an increase in muscle mass.
This is important, for example, after a strenuous diaphoretic workout. Our organism then needs time and sleep to repair the muscle fibres strained during the training. Unfortunately, somatotropin is increasingly used as a doping agent due to its positive effects on muscle building.
Growth hormones also promote protein biosynthesis in our body, meaning the formation of new proteins. Proteins are vital and for example in the form of structural proteins, enzymes, receptor proteins and/or immunoglobulins involved in many body processes. Sufficient and qualitatively good sleep is absolutely essential for cell regeneration in the whole body. Insufficient sleep leads to a deficient release of corresponding hormones, which in turn has the consequence that our body is no longer maximally efficient on the following day.
Does sleep even help against Alzheimer's?
Moreover, scientists also discovered that sleep also has an effect on brain metabolism. In simple terms, the so-called "glymphatic system" is a drainage system formed by special glial cells in the central nervous system. This system is mainly active during sleep and ensures that the intermediate products that accumulate in the course of the day are channeled out from our brain and are ultimately supplied to the lymphatic system. This can be of particular importance in relation to neurodegenerative diseases (e.g. Alzheimer's). However, the effectiveness of this system decreases with increasing age which explains why predominantly elderly people are affected by neurodegenerative diseases.
Sleep is particularly important after vaccinations
Sleep is not only important for the functioning of our brain but also for the immune system. Lack of sleep is often accompanied by a weak immune system. This increases the susceptibility to infections. Once we have fallen ill, there is often an increased need for sleep. This can be traced back to the fact that our body uses every means at its disposal to render the pathogens in the organism harmless. Furthermore, sleep also has an influence on the so-called " immunological memory". Studies have shown that vaccinations followed by short-term sleep deprivation produce a worse vaccination effect. Exciting to know in this context: Even one year after the vaccination the amount of antibodies in the blood of "well-rested" test persons was significantly higher than that of "tired" test persons.
Furthermore, sleep and psychological well-being are closely linked. If we have not slept well enough, we quickly give a resty reply and are less able to concentrate. Our psyche can also suffer from this in the long term. Sleep disorders are often accompanied by mental illnesses such as depression.
Apparently our body rests at night. Yet, this is not the case. During sleep our body - to put it crudely - is in a state of full blast! Organ systems and muscles are repaired, the immune system is strengthened. During sleep, the body frees itself from harmful metabolic products. And many other processes are set in motion that ensure that we can master our everyday challenges. For active people and athletes sleep has a very special meaning because only those who sleep sufficiently will be able to increase their performance in the long term. You can find out what "sufficient sleep" exactly means in our free webinars and video chats.