Who doesn't know it: like every morning, the alarm clock rings way too early and the unwelcome goodbye from deep sleep feels like someone has fetched you from another dimension. On the other hand, we find getting up from the light sleep phase to be much more pleasant. But what is the difference between the deep sleep phase and the light sleep phase? You can find out here which cycles our sleep goes through during the night and how you can use this knowledge for yourself!

Couple lying in bed

1. Sleep is not just sleep

While we don't consciously perceive any difference and sleep usually just seems like a strangely blurred time of absence, our body does a lot while we sleep. We also go through several sleep cycles in one night. In principle, sleep research distinguishes between two different types of sleep: REM sleep and non-REM sleep. REM stands for the English term "rapid-eye-movement" and marks the time when we sleep deeply and dream. The eyeballs under our eyelids move back and forth quickly. 

2. Non-REM sleep: falling asleep phase, light sleep phase and deep sleep

How does our body actually notice that it's evening and we can slowly get tired? Our endogenous hormone melatonin, which regulates our day-night rhythm, helps us here. The changing light conditions from bright to dark releases melatonin, which makes us feel tired. When we then lie down in bed and close our eyes, our consciousness slowly slides from being awake to asleep. During the light sleep phase, the muscles slowly relax and the ability to react decreases. In addition, our breathing becomes even and the body temperature decreases. Finally comes the deep sleep: This phase is the most important for our recovery.

Woman sleeping in bed

3. The REM phase 

In the last phase of a sleep cycle, we dream the most intense dreams that we can sometimes remember in the morning. On average, one dreams about four dreams a night, but usually only remembers a maximum of the last two dreams before waking up.  

In this phase, the wake-up threshold is highest, which means that we find it extremely uncomfortable to be woken up from this phase and feel in the morning, even though we may have even gotten enough sleep completely exhausted and tired. To prevent this, it helps if you first monitor your sleep and determine how many hours of sleep you need per night. And yes, everyone needs different amounts of sleep! While the normal sleep duration for children is 9 hours, adults only sleep about 7 hours a night on average. From the age of 55-60, most people only sleep about 6 hours on average.

But as I said: This is only an average value. The best way to find out how much sleep you need is to simply listen to how you feel. Do you always sleep around 7 hours and have to struggle to get out of bed in the morning? Then you're obviously not sleeping enough! If you now always set your alarm clock to wake you up from your light sleep phase, you will notice that you start the day much fitter and better! It's very simple: your sleep duration simply has to be divisible by 1.5 or 90 minutes. A good sleep duration is therefore, for example, 6 hours (4 sleep cycles), 7.5 (5 sleep cycles) and 9 hours (6 sleep cycles).

< span class="NormalTextRun SCXW75099589 BCX4">Author: Jane-Lee Fromm

Eliane Wikert