it seems the pump can be caused by different things...some ppl say estrogen?...some ppl say not enough water?...do you stretch your back ever? (grabbing the back of your ankles knees slightly bent and pulling up) i got unbearable pumps my last cycle...this cycle the only thing different i'm doing is stretching my back...back day or not and i get no nasty lower back pumps...i used to want to lay down on my back in between sets...stretching, lots of water, ala, and an anti estrogen even should all help...how many mgs?