My arms are really lagging especially my biceps. They are flat, soft with almost no peak. The problem is that I can work them everyday, I never feel that my biceps are tired or sore. I train arms only 1 a week at the moment but I tried 2 arm days before with no success.
I am constantly changing my arms workout but it would look like this:
EZ cheated curls 5-6 sets, close grip (4 of them very heavy)
Preacher curls 4 sets
Hammer curls 4 sets

or

Db curls 5-6 sets, shoulder wide grip (4 heavy sets)
Incline DB curls 4 sets
Concentration Curls 4 sets or high cable curls

Triceps:
Skull crushers 5 sets
Overhead extension 4 sets
Push down 4 sets

or

CGBP 5 sets
skull crushers 4 sets
push downs 4 sets



This is not about the: eat more or train harder problem cause I always go to failure and sometimes I use a spotter to lift the weight for me and I just let it down slowly. I also use to do drop sets on my final sets. Anyway, I always leave the gym with a crazy pump but they are not growing... Every other muscle group is growing but arms are not... Also I have a huge thoracic box which makes them look even smaller.