Well Malt, It seems as SemperFi gave you my answer. I use Taurine and liquid orals to combat wicked pumps, Cramping. It sounds like you just trained them like a champ... Don't listen to the guy in the gym about genetics. Of course a lot of it is genetics but if you train hard and eat right you can grow any muscle group. If I listened to that guy i'd be a fat slob. Instead, I train hard and watch my diet...