Because I have a really bad back and wrist xD Lol.
130 actually hurts both of them, but I do it from time to time. I broke my wrist and now two of the bones in it are still jammed, and I tore a muscle in my back about a year ago. As in, I ripped the thing in half. And the tendon in my right thigh popped off, and I had to get it snapped back in place. I've had so many injuries, that it makes it really painful to swing absolutely as hard as I can. My maximum speed is 140, but the last time I did that, I had to go get a cast for my wrist :/ So I don't do that anymore. Kinda sucks.