Sleep should occupy nearly a third of our lives. Often seen as a waste of time, it is of paramount importance for our health and well-being, on par with nutrition or physical exercise.

What are his exact functions? What are the sleep cycles? What are the repercussions of poor sleep or nights that are too short? How to improve it? How can diet and micronutrition help?

Find "60 minutes for better sleep", short videos offering practical tools to regain sleep, onformation.bn-nutrition.ch ! !

Sleep - What are its functions?

Sleep is a vital function, essential to:

• the good recovery of the organism and cellular renewal
• In the production of hormones, including growth hormone, which develops muscles, bones, cartilage...
• to the strengthening of memory and learning capacity

To fully understand the functions of sleep, let's go back to the unfolding of a sleep cycle. A sleep cycle lasts about 1.5 hours and is composed of 5 phases:

Stage 1

It's the very light slow sleep (falling asleep phase).. We feel like we're on a cloud. The body relaxes, we start to recharge. We hear the noises, but do not wish to respond to them.

The brain waves associated with phase 1 sleep are the waves. Alpha, which travel at a speed of 8 to 14 Hz per second. These are the waves of relaxation and regeneration, of calm and clear thoughts. When the brain sends you these waves, you feel creative and particularly activate acetylcholine.

Stage 2

It is the light slow sleep. We still hear, but we no longer understand.

The brain waves associated with stage 2 sleep are the waves Theta, which circulate at a speed of 4 to 8 Hz per second. Under the effect of Theta waves, we become drowsy (GABA). These are the waves of nerve regeneration, synchronization of the two cerebral hemispheres, dreams, and the subconscious.

Stage 3

It is the stage of deep slow sleep. We no longer hear anything, we are cut off from the world. The whole body is relaxed, the breathing slows down, the body temperature drops.

The waves associated with phase 3 sleep are Delta waves, which travel at a speed of 0.5 to 4 Hz per second. When the brain transmits a majority of Delta waves, we then sleep deeply (serotonin), without dreaming. These are the waves of the global regeneration.

Stage 4

It's very deep, slow sleep. We sleep very deeply, it's during this phase that the body really rests, that we best produce the growth hormone, therefore the defense and systems. regeneration of the organism. The memory strengthens, it's the beginning of dreams.

The waves associated with stage 4 sleep are also the waves Delta, which circulate at a speed of 0.5 to 4 Hz per second. When the brain transmits a majority of Delta waves, we are then in deep sleep (serotonin), without dreams. These waves are associated with two anti-aging hormones, DHEA and melatonin. Delta waves help suppress the production of cortisol, a hormone linked to stress and accelerated aging.

Stage 5

It's the paradoxical sleep, these are dreams, that's where we are class and that we filter what we saw and learned the day before.. It's the reboot of his cerebral hard drive. This phase lasts between 10 and 20 minutes.

During REM sleep, the eyes move intensely under the eyelids, the neck becomes stiff, just like a man's genitals.

Remembering one's dreams is a sign of good brain function: people who remember their dreams the best are often the most creative. In fact, dreaming is essential for our brain to function properly.

The waves associated with stage 5 sleep are Gamma waves, which travel at a speed of 30 to 45 Hz per second. When the brain transmits a majority of Gamma waves, brain and neuronal activity is at its peak, such as during creative processes or solving complex problems.

What happens when we sleep poorly?

Lack of sleep weakens the immune system, which speeds up oxidative stress and ultimately increases the rate of inflammation in the body. It leads to a decline in mood, an increase in heart rate, impaired vision, a decrease in muscle strength, a decrease in learning and concentration abilities... Among other things.

Some studies and random numbers...

• During sleep (specifically during REM sleep, as mentioned above), the brain resets the connections between neurons. These connections are often overloaded during the day and can limit our learning abilities. Therefore, if you sleep poorly, there's a high chance that you will learn poorly.
• By sleeping 3 hours less than necessary for 3 days, endurance tests show a deterioration of results; alterations in the structure of some neurons can also lead to motor coordination disorders.
• Another interesting test: an Australian study shows that a person who sleeps less than 6 hours a night for two weeks has the same reaction times as an individual who has 1 gram of alcohol per liter of blood!
• The immune system is weakened in people who sleep less than 4 hours per night, which increases the rate of inflammation as long as the body has not recovered from the lack of sleep.

So what to do and how to improve one's sleep? See you tomorrow for some tips given by Lionel Fleury, BN ambassador and talented osteopath!