I have been wondering about upper body mass.. I guess the muscles decrease but you still have that shoulder span. Unless your bones shrink sideways as well? Hips expand, shoulders shrink? the muscles Im worried about are the ones on top of the shoulders that connect to the neck.. just feeling them they're noticable! My hair can only hide them so much!! Also if your neck shrinks would that make your adams apple stand out any more?
I left my last job a few months ago because I had to do some heavy lifting which made me freak out about my upperbody becoming more defined! :S