7 essential information to know about sleep
1.What is sleep? How is it represented in a day?
Sleep is the activity of the brain exerted by our internal clock . It is she who signals to our body the time at which you should go to bed or the time at which to wake up.As a reminder, our body assimilates the day into 2 distinct parts: sleep which takes place (on average) from 11 p.m. to 7 a.m. and awakening (on average) from 7 a.m. to 10 p.m.
2. What happens in our body when sleep comes?
When night falls, our brain produces more melatonin (the sleep hormone), giving us that feeling of sleep and putting certain areas of our brain to rest.When falling asleep, our body temperature drops to 36.5 degrees (which is usually 37.5 degrees) but will rise again from 5am .
There are 4 sleep phases which come in the form of 4 to 5 cycles per night:
- The slow wave sleep phase lasts about 90 minutes , the sleep is very light, we can easily be awakened.
- The slow wave sleep phase comprises 50% of our sleep time . Our brain activity is slowed down and during this phase we tend to wake up more easily.
- The slow deep sleep phase lasts about 1 hour, it corresponds to restorative sleep (the sleep that allows us to be in good shape the next day).
- The paradoxical sleep phase lasts about 30 minutes, it reproduces the activity of wakefulness but our body can no longer move (only the eyeball is still in action) and it is also the moment when we dream.
3.Why do we have dark circles when we are tired?
Do you see these dark circles, bags or any other wacky nicknames to define these traces under our eyes? Yes, those that we no longer support or try to hide by all imaginable means...
Their presence under our eyelids is justified by the circulation of a translucent liquid (from our blood) which is none other than the lymph (ah the vicious one). It is the beating of our heart and the contractions of our muscles which work in slow motion and which thus allow the good blood circulation of the lymph.
In the case of poor blood circulation, an excess of liquid will slightly deform the skin under our eyes and form these famous "pockets". Don't worry, they generally subside when you wake up.
But when there is a surplus of fatigue, the liquid no longer circulates or with difficulty and our pockets remain (oh the sadness). As for the color of our dark circles, the fault is poor circulation, which will make them appear more or less dark, depending on our skin color.
4.Why is getting enough sleep important?
When we sleep, we allow our body to rest, to regenerate physically. A lack of sleep can create additional stress, weight gain, fatigue (temporary or long-lasting)… Remember that we recover from the fatigue accumulated during the day.
Getting enough sleep (7 to 8 hours a night) allows our brain to record information accumulated throughout the day, creating new nerve connections and improving our memory . It also helps to release pressure : our breathing, digestion and heart rate slow down, the muscles relax. We feel our whole body soften!
5.Why do we rub our eyes when we are sleepy?
Sign of fatigue, rubbing your eyes has become a reflex for many of us! To visualize well, our eyes are protected by the tear film , which is made up of a watery layer and a thin fatty layer, thus preventing the evaporation of tears and the drying out of the eyes.
For their proper functioning, our eyes must have this film in perfect condition, it is for this reason that we very often blink our eyes without noticing it.
When we're tired, we tend to blink less, which makes them more irritated and gives them that tingly feeling. When we rub our eyes, we remove dust or other foreign bodies present on the surface of the eye and the film will thus be able to regenerate by protecting our eyes.
6. Why shouldn't we look at our screens before going to bed?
As seen previously, our body, at nightfall, produces melatonin (sleep hormone) which promotes falling asleep ... But screens (tablets, television, smartphones...) turn out to be real harmful for the quality of our sleep. The blue light emanating from it sends the wrong message to our brain, suggesting that the body is in the waking phase, which will alter the production of the precious sleep hormone and delay falling asleep.
7.Why should we take a nap?
The nap is a short episode of sleep, not to exceed 10 to 20 minutes (we're not talking about a 3 hour sleep!) if we exceed, we risk being even more tired than before and disrupt our biological clock! This nap is a time of rest that will recharge our batteries, relax our muscles, fight against possible stress but also improve our concentration.