Quote Originally Posted by kostakv
i DONT UNDERSTAND HOW RECEPTORS HAVE ANYTHING TO DO WITH IT....I UNDERSTAND SCAR TISSUE, BUT I ALWAYS THOUGH IT JUST SLOWLY SEEPED INTO THE BLOOD STREAM...WHAT IS WITH THESE "receptors"

Receptors are sites on DNA were steroid hormones attach and cause genes to be activated in each muscle cell. In the case of steroids, they cause protein synthesis to take place which is what increases the size of your muscles. Keep in mind this is a very very basic explanation and there are a multitude of things that occur.