Our Sleep Cycles: Understand Your Brain And Improve Sleep

REM cycles, non-REM cycles, delta waves, theta waves, K-complexes… Our sleep cycles are as fascinating as they are essential to our lives. As Friedrich Nietzsche said: ““. In addition, when you finally manage to fall asleep, your mind gives you what already belongs to you: your dreams.

But as you probably know, in recent decades we have become an almost sleepless civilization. Almost 40% of the population has sleep disorders and 90% have difficulty getting restorative sleep at least once a year. Our lifestyle, stress and certain habits, such as intensive use of technology, affect our sleep hygiene.

Therefore, it can be very interesting to understand what actually happens in the brain while we sleep. After all, the sole purpose of the brain is to facilitate deep sleep during these hours. Basically, night is the time when the body performs tasks that are important for your well-being. To maintain good physical and mental health, you need to sleep well to strengthen memory, remove toxins and eliminate irrelevant data and information.

Let’s dig a little deeper into our sleep cycles and their exciting world.

The five phases: our sleep cycles give us a good night’s sleep

Each sleep cycle lasts about 90 minutes. Consequently, you go through about five or six cycles each night. As you may know, this means that you wake up tired, confused and lethargic when you wake up in the middle of one of these cycles without reaching REM sleep.

Ideally, you should sleep throughout the course of the five phases. At the very least, you need to sleep long enough for the cycle to be repeated four times. Sleeping less than five hours does not give the brain enough time to perform all the necessary processes and “restart” itself.

Let’s take a detailed look at each sleep cycle.

Phase 1: Our sleep cycles begin with light sleep

The first phase begins already when you feel relaxed and comfortable in bed. It lasts about fifteen to twenty minutes. Phase 1 is the low threshold between wakefulness and sleep. If you do an electroencephalogram (EEG) on someone in the light sleep stage, their brain shows theta waves (3.5-7.5 Hz).

Step 2: Light sleep, heart rate begins to slow down

Here the breathing begins to slow down, the heart rate drops and the brain waves slow down. The only difference between phase 2 and phase 1 is that in phase 2 the K-waves or sleep spiders increase (sudden increases in brainwave frequencies). These frequencies tend to be between 12 and 14 Hz, which is very low. The purpose of these sleep spiders is to prevent you from waking up.

It is also very common during this phase that you experience a certain thing that you are probably very familiar with. We’re talking about dreaming that you’ll fall. Researchers believe that this feeling comes about as a result of low heart rate.

The brain must make sure that everything is okay and under control. Therefore, it sends a sudden stimulus that your mind interprets in the same way as it would if you fell.

Step 3: Transition

You could say that this is halfway through your sleep cycle. This is a short phase; it only lasts five minutes. During that time, the theta waves, ie slow waves, become shorter and become delta waves, which are more intense. People who go to sleep often do so during this point in the sleep cycle.

Phase 4: Deep sleep

You have reached the deepest stage of sleep, which lasts about 20 to 30 minutes. When your brain is in this phase, it is very difficult to wake up. The delta waves have completely taken over by this time, and your sleep is truly restorative, in every sense of the word.

If you wake up during this phase, you will feel groggy, disoriented and foggy. People who suffer from insomnia experience this very often. In general, they do not reach the fourth phase.

Phase 5: The REM cycle – the dream and nightmare stage

This is the most important and most interesting sleep cycle. Most people know that dreams and nightmares occur during the REM cycle. In addition, the theta waves take over again during this phase. Consequently, in an EEG, you see the same brain activity that occurs when you are awake. This is because the brain is extremely active during this sleep stage.

The REM cycle is also known as paradoxical sleep . It makes up about 25% of your sleep cycle. The earlier phases, called non-REM cycles, or slow sleep cycles, make up the rest. Thus, the entire structure of night sleep (under normal conditions) is performed in a process lasting about 90 minutes.

We emphasize “normal conditions”, because if you take medication to treat sleep disorders, it can change this cycle slightly. Chemicals can alter the flow of phases and brain waves.

Ideally, you should be able to sleep well without using medication. Instead, try some natural strategies, such as managing stress, paying attention to your schedule, and being careful about what you eat. Limiting exposure to blue light from screens is also important. Even simple things like the temperature in your room can affect your sleep.

To sleep well means to live well. Understanding the sleep cycles and aiming for a night of deep, restorative sleep will help you feel better every day.