So I have a weak upper body, so much so that in the last 200 of a mile or 800, my shoulders and arms will be burning so much that I almost feel like my legs could go faster, but my arms cant keep up. This summer I'm going to try to fix this. I'm going to do the normal stuff for upper body (curls, bench, ect.) but how do I gain strength without putting on weight? Should I just do the normal three sets of ten, or should I do it a different way?