carabin saidI can't believe people that are into working out, as above, would say there are no upper or lower pec muscles, what about clavicular vs sternal pectori
Forgive my lack of clarity. Bear with me, as I explain what I meant in greater depth.
Clavicular and Sternal heads are 2 parts of the same muscle, the Pectoralis Major.
Research indicates that you may be able to isolate the clavicular and sternal heads. HOWEVER
, the sternal head is what most people view as "the chest." From experience, when confused bodybuilders say "lower chest," they mean the nipple-area of the chest/the part where your chest makes a nice shelf above your lower ribs. This part of the chest is absolutely not
isolatable, anatomically speaking, as not only is it one single muscle, it is one single head of one muscle.
With that...Welcome to one of the most heated debates in bodybuilding!
In one corner, we have the bodybuilding nerds who research and analyze anatomy extensively. These bodybuilders largely believe that the pectoralis major cannot be isolated between parts.
In the other corner, we have the intuitive bodybuilder who goes by feel and anecdotal evidence from other bodybuilders. These folks believe that you can isolate upper (the bulk of your chest) and lower (the "shelf," as I explained above) chest.
Neither is a better bodybuilder. One simply has better facts.
Do your own research to find the troves of information on the subject.
Through my vast and extensive research, the most reasonable, rational, scientific evidence I've found on the subject leads me to the conclusion that you cannot isolate different parts of one single muscle. My citation above was simply an easy-to-find breakdown of the subject that mirrors my own finding.But, I'm not here to convince you. Do the research and draw your own conclusions.
At least now the OP has some more information, and knows which questions to ask for further research.
I suggest starting here... http://www.exrx.net/