system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 - If the brain releases chemicals that paralyse the body during sleep, how come people still turn around many times throughout the night?
gpt
That is because sleep always goes in cycles. 
These chemicals are released during a REM cycle. You get about 4 of them and they last around 20/30 minutes. 
These are the times where your brain activity is high but you get paralyzed becaude otherwise your body would act upon your brain activity. 

Otherwise you are not paralyzed but your brain activity is extremely low. These are the times where you turn around.