This sequence wakes up all those little muscles in the arm, hitting each one from multiple angles (you're going to be sore!) to really tighten and tone. Do the series six times a week, and don't forget your half hour of fat-burning cardio each workout day.source
Stand with feet a little wider than hip-width, arms extended out to sides, palms down as if palming a basketball (A). Leading with pinkie, rotate arm forward from shoulder socket until palms and elbows are facing up. Reverse motion, this time leading with thumb (B). Do 30 to 40 reps.