text: what happened to your body muscles when  you sleep?   in deep sleep nothing your muscles are relaxed,in rem sleep they become paralyzed unless you have a disorder that damged that mechanism in your brain then you would sleep walk or eat during them rem cycle or act out your dream,without being conscious of your actions ,sleep occurs in cycles and stages and it the rem stage is short but gets a little longer which each progressive cycle, i think this is the phase where the body repairs itself but i am still reading up on it so dont take my word for it