Why do you want to increase arm size hitmandonny? I just get the impression power is not a weak point for you and even if it was I have gathered from a lot of the recent posts that power mostly comes from other body parts.

How much time have you got until your nationals? Do you think now is the best time to be trialling a new weights routine if it might make it harder to make weight or risk making you slower?

There's some lean little African pro guys i know who seem to incorporate plyometrics into their training a lot. They just randomly insert jumps into their warm up etc. I still have to be careful of injury and can't copy what they do (so unfortunately haven't spied their routine) but I'd guess that type of thing is more like to help over the short term than weights?