You are paralysed while you are asleep: iLIVE

Believe it or not, when you are asleep your body is virtually paralysed, probably to prevent your body from acting out aspects of your dreams.

According to a Wikipedia article on dreaming, “Glands begin to secrete a hormone that helps induce sleep and neurons send signals to the spinal cord which cause the body to relax and later become essentially paralysed".

Source: http://www.uphaa.com/blog/index.php/dreams/