The sleep cycle is a set of phases that begin from the moment the person falls asleep and progresses and becomes deeper and deeper, until the body enters REM sleep.
Normally, REM sleep is the most difficult to achieve, but it is at this stage that the body can actually relax and where the rate of brain renewal is higher. Most people follow the following sleep phase pattern:
- After being in the REM phase.
- The body returns to phase 1 and repeats all phases until it returns to the REM phase.
- This cycle is repeated during the night.
- But the REM sleep time increases with each cycle.
Learn about the top 8 disorders that can affect the sleep cycle
The body goes through several sleep cycles during one night, the first lasts about 90 minutes, then the duration increases, up to an average of 100 minutes per cycle.
An adult usually has between 4 and 5 sleep cycles per night, which ends up getting the necessary 8 hours of sleep.
Sleep can be divided into 4 phases, which are interspersed
This is a very light sleep phase that lasts about 10 minutes. Phase 1 of sleep begins when you close your eyes and your body begins to fall asleep, however, it is always possible to easily wake up with any sound that occurs in the room, for example.
Algumas características desta fase incluem:
Durante esta fase, os músculos ainda não estão relaxados e, por isso, a pessoa ainda se movimenta na cama e pode até abrir os olhos enquanto tenta adormecer.
A fase 2 é a fase a que quase todo o mundo se refere quando fala que tem um sono leve. É uma fase na qual o corpo já se encontra relaxado e dormindo, mas a mente está atenta e, por isso, a pessoa ainda consegue acordar facilmente com alguém se mexendo dentro do quarto ou com um barulho na casa.
Esta fase dura cerca de 20 minutos e, em muitas pessoas, é a fase na qual o corpo passa mais tempo ao longo de todos os ciclos de sono.
This is the deep sleep phase in which the muscles relax completely, the body is less sensitive to external stimuli, such as movement or noise. At this point, the mind disconnects and therefore there are no dreams either. However, this phase is very important for the repair of the body, since the body tries to recover from the small lesions that appear during the day.
REM sleep is the last phase of the sleep cycle, which lasts about 10 minutes and usually begins 90 minutes after falling asleep. At this point, the eyes move very fast, the heart rate increases and dreams appear.
It is also at this stage that a sleep disorder called sleepwalking can occur, in which the person can even get up and walk around the house, without even waking up. The REM phase takes longer with each sleep cycle, reaching up to 20 or 30 minutes.
Learn more about sleepwalking and 5 other strange things that can happen during sleep.