What size weights do you use while working out?
I know it probably depends on what type on workout you are doing. Today I did the 30 Day Shred level 1 with 5 pound weights and my arms feel like they're going to fall off! LOL Yet the other day I was trying out P90X and used 10 pound weights most of the time. I guess the big difference is in the Shred you are also moving your legs which makes it more difficult then just standing still. And for my triceps I can still only use 3 pound weights most of the time.