have nothing to do with growth they determine Ripped Muscle X which muscle(s) receive the stimulation.The 'method' you use is what will cause your muscle to become bigger, stronger, faster, etc.. Let's make sure this is clear, as many people do not understand this, and it is an important point - it is HOW you train - NOT the exercise itself - - that cause muscles to grow. Research on muscle recovery for medical reasons has been done for hundreds of years now - that's correct - 100's. Research was greatly stepped up after World War 2 - it was at this time that the benefits of resistance training began to be understood.