Do you know how your sleep cycle works?
If you thought that going to sleep was as straightforward as drifting to sleep and waking up in the morning, then you would be wrong! There’s actually four stages of sleeping and one full cycle of sleep only takes 90 minutes. You will go through this cycle anyway between 4-5 times, depending on how long you usually sleep for. So what are these four distinctive stages of sleep? We’re going to go through them now…
Stage one – non-rapid eye movement (NREM) sleep
As you’d imagine, this first stage is very light sleep in bed where your eye and muscle activity are slowly decreasing. You’re easy to wake up in this stage, and it’s here that you’re likely to experience twitching or the infamous hypnic jerk.
Stage two – NREM2 sleep
This is the period which prepares you for deep sleep, muscle activity decreases further and your heart rate and temperature drop further too. Brain waves slowly decrease however there will be small bursts of brain activity in this stage still.
Stage three – NREM3 sleep
In this stage you’re in a much deeper sleep, the brain emits delta waves which prepares you for the final stage. You would also be fairly difficult to wake up at this point, as this is the period of sleep which helps you feel refreshed in the morning. With restoration happening in this phase, it makes sense that this stage occurs for longer periods earlier in the night.
Stage four – REM sleep
This is the most intense stage of sleep where your eyes move from side to side quickly, whilst your eyes are closed of course. In this phase you’re most likely to have dreams, which are caused by extreme brain activity in which the frequency isn’t so far off that of being awake. Also an interesting fact about this stage of sleep is that our limbs become paralyzed temporarily, and that’s to stop us acting out our dreams!
Both NREM and REM sleep are important for our memories and being able to attain them, as well as feeling refreshed in the morning. A good night’s sleep occurs when you go through this cycle 4-5 times a night.
It’s quite bizarre and funny how we experience such fluctuations in brain activity when we sleep, right? Did you know this is how the sleep cycle worked before reading this blog? Let us know in the comments!