【It clicked】 Non-REM sleep and REM sleep

The theme this time is "Non-REM sleep and REM sleep."

To be honest, I thought I knew about them vaguely, but I didn't really understand them well.
However, as I looked into it again,
"Oh, so that's what it was."
I had a moment where it clicked, and I feel like I've found some hints for improving my sleep.

First of all, sleep is broadly divided into two types: "non-REM sleep" and "REM sleep."

Non-REM sleep is what is known as a "deep sleep" state.
Brain activity decreases, the body is relaxed and resting well, and the deep non-REM sleep that occurs especially right after falling asleep is said to be extremely important for recovering from fatigue.
Since growth hormone secretion is also active at this time, it is the central period for physical recovery.

On the other hand, REM sleep is a "light sleep" state.
While the body is resting, the brain is active to some extent, which is a characteristic, and this is also when you dream.
It is considered to be more involved in mental recovery, such as organizing memories and processing emotions.

These two types of sleep are repeated alternately throughout the night. By transitioning from non-REM sleep to REM sleep in cycles of approximately 90 to 120 minutes and repeating this multiple times, both the body and brain are recovered in a balanced way. The fact that there is this "cycle" was a pretty big realization for me.

Until now, I had been thinking,
"As long as I sleep for a long time, it's fine"
"As long as I don't wake up in the middle, it's okay"
But in reality, it was important how deeply I could enter non-REM sleep and how not to disrupt this cycle.

For example, if you wake up during the deep non-REM sleep right after falling asleep, "sleep inertia," which leaves you with strong sleepiness or sluggishness, is likely to occur. Conversely, it is said that if you wake up during the REM sleep timing, it is relatively easier to wake up feeling refreshed.

Understanding this far, it finally connected, and I realized, "So this is what sleep improvement is about." I realized that it is important not just to secure sleep time, but to be conscious of this rhythm.

For example, by fixing the time you go to bed and wake up as much as possible, it becomes easier to regulate your internal rhythm.
Also, by avoiding smartphones or strong light right before going to bed, it becomes easier to enter non-REM sleep smoothly.
I was able to understand that all these actions lead to regulating this sleep cycle.

Furthermore, what was big for me was that I came to be able to think,
"Waking up in the middle is not a bad thing."
It is said that people wake up lightly many times throughout the night, and that in itself is natural.

What is important is whether you can properly return to the next cycle after that. Because my way of thinking changed to this, I have become less excessively anxious even if I wake up a little in the middle of the night.

Since my girlfriend is a long sleeper, until now I had thought somewhere that
"Sleeping long is justice,"
but now I feel that "quality and rhythm" are just as important.

By understanding the mechanisms of non-REM sleep and REM sleep, I was finally able to grasp sleep as a "structure" rather than a "sensation."

I haven't been able to control it perfectly yet, but at least I can see the direction of "how I should improve it." From now on, based on this understanding, I would like to further improve the sleep environment and lifestyle habits that suit us.