You are going to have to try both methods because what works for one person may not work for you. When I worked my arms together and 2x's a week I saw really nice improvements. Right now I'm only working them once a week; just to try something new and keep from becoming repetative, but as soon as I get my life organized and can devote my time and energy to lifting hard and eating right I'm going back to 2xs a week for arms...........Trial and error sweetie!