Sleep cycles are a term that we have been hearing for some years now so what they are? How did people sleep properly 100 years ago without knowing about them? The concise explanation is that sleep cycles are the stages of sleep that we go through when we finally nod of and begin to sleep, and what happens before we wake up.
A Longer Explanation
Sleep cycles are a way to attempt to explain what our brain is doing while we are asleep, and it goes through some stages of activity before we wake up. There are generally accepted to be five different cycles of your sleep. The below is the five steps that we will usually go through as we drift off to sleep.
1) The first stage is that when you start to drift off into a light sleep as your muscles begin to relax and tensions begin to ease.
2) The second stage is when, as you fall deeper into sleep your breathing begins to develop a natural patern while the rate of your heart starts to slow. As your internals begin to slow slightly, your body temperature cools with it.
3) The third stage is when you move through the veil of light sleep and into the realm of deep sleep. This stage is where your brain starts to generate slow delta waves. These are also at times known as slow wave sleep.
4) We are now in a profound sleep with rhythmic breating. Your muscles are more relaxed than before, and your brain continues to produce the delta waves.
5) This stage is where the REM sleep that we have probably heard of occurs. REM is short for Rapid Eye Movement and denotes that period where our brain waves begin to speed up and dreaming begins to happen. Our muscles relax further, and our heart rate increases and your breathing turns to a rapid and shallow state.
The exciting thing is that we do not just go through each of these cycles the once during a nights sleep. Instead, we tend to spend 60 minutes to ninety minutes in each stage of sleep, and once the period has completed, it repeats. As it happens, we generally move to more time in phase 5, and not as much time in stage 4 as our body fulfills the need for deep sleep.
This explanation is why we recall dreaming, then nothing, then another dream. It is because we are moving through stages then back again. The above steps will also help explain why some people like myself always wake up just before the alarm, regardless of the time I went to bed or the amount of time that I have been asleep. Our brainwaves are keeping some sort of timing track and move you back into a lighter sleep as the time draws near for your alarm clock to go off, and you need to wake up and get out of bed.
I hope that the above has been informative and that you can use the information contained to gain a better understanding of your sleep patterns.