Supination has a definite purpose and is not something you want to leave out of your program.Having said that, it will not "add more to your peaks." It will just insure full development of what is already there.It's often said that supinating your hands while doing DB curls will really "peak" your biceps. Well, assuming you believe that peaks are the results of genetics and not exercises, is supinating a waste of time? Would one be better off sticking to normal BB curls or just regular DB curls keeping your palms facing foward throughout the movement?