ive been training for almost two years now........im a completely natural trainer (never taken any supplements of any sort or any steroids or performance enhancing drugs). I havent taken any length of time off in this 2 year period. All is going well with my training. Only thing that bugs me, is that the peaks of my biceps just dont seem to be growing. If i flex the arm, then its hard to see the peaks of the biceps. My arms have definately got bigger though. Its not as if im not lifting much. For example, heres a breakdown of what i commonly perform on bicep day.
single arm dumbell curl:- (3*8) 22kg (could do 24kg now)
single arm preacher curl (concentrated curls):- (3*8) 20kg (could do 22kg now)
double arm ez bar curls:- (3*8) 55kg
etc. you get the idea.
i cant understand why i cant seem to develop a peak. When my gym buddy flexes his arm, you can clearly see the peaks of his biceps.