I've been using 3 lb weights (don't laugh) for one of my 45 min. cardio classes during the week. I used to be only able to do 2-3 songs. I can now do every other song, and sometimes more. Going to work on making my movements more full, controlled, and faster. Right now things are half-time of what my legs are doing, the motion is partial (and gets tighter as I tire), and I rely on momentum too much. I notice my shoulders are getting less fussy the day after my workouts, so that's good! Visually, I can't say that I notice a difference in the way my arms look. I'm getting older, and I'm pretty slim, so I'm a little "sinewy" looking. Not sure how to avoid that. Is there a diet that just puts a nice layer of soft on the arms and bust only?