A period of sleep includes < b>3 main phases, themselves able to integrate up to 6 cycles of 90 minutes on average. A restorative night usually contains these stages, but their duration varies depending on your age and body type. Overview of sleep and its episodes to better understand its role in health.
The stages of sleep: an outline
The melatonin, the sleep hormone, is secreted by the body in the absence of light. Thesleep cycle lasts about 90 minutes during which the body transitions from one period to the next. All of these phases repeat up to 5 times in one night.
Normally, a cycle includes a phase of light slow sleep, deep slow sleep and REM sleep. Your sleep needs are regulated according to your internal balance and biological clock.
When you are in sleep debt, your disposition to fall asleep is high. As soon as you recover these lacks, it decreases proportionally. This is called internal balance or homeostatic regulation.
When you sleep, you experience intense sleep pressure between 1 a.m. and 5 a.m.< /b>. You may also experience this sensation during the afternoon, usually between 2 and 4 p.m. We are talking here about circadian regulation.
The Stages of Sleep: Stage 1
The light slow sleep, also called sleep phase, occurs as soon as you close your eyes. It is accompanied by a slowing of your breathing, muscle relaxation and possibly a slight sensation of falling.
At this point, sudden commotion, sound, or light may wake you up. It's the same for snoring, a problem for those who sleep together. Light sleep occupies up to 50% of your total sleep period.
The Stages of Sleep: Stage 2
deep slow sleepis manifested by a muscle sluggishness, regular heartbeat and sustained breathing. You no longer hear what is happening around you and therefore cannot react to any external stimulus. You are in this sleep state on average for 20-25% of your total night's sleep.
The Stages of Sleep: Stage 3
The deep sleep represents the third < /strong>sleep phase. It allows cellular regeneration and strengthening of immunity. It is sometimes accompanied by somnambulism in some individuals, especially during childhood.
The body is not still, as in the muscle atony of the previous phase. However, the individual wakes with difficulty and does not react to any stimulation. It is generally equivalent to 10 or 20% of the duration of sleep.
The Stages of Sleep: Stage 4
REM sleep is characterized by an irregular heartbeat, intense brain activity, muscle relaxation and breathing uneven. It also features eye movements, hence the abbreviation REM in English for Rapid Eye Movement. Your dreams typically occur during this sleep phase which forms about 25% of your overall sleep.
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