I have a few questions about arm workouts. What are some good exercises for the arms, my arms are getting stronger and harder but they grow at a much slower rate. It may be my sets or the amount of reps, I normally do a warm up set and then 3 reg. sets. My reps. are 10, 8, 6, increasing the weight each set. My three normal exercises are sit down curl, cables, and barbell curls. I switch cables with concentration curls every other week. Does anybody recommend any changes?