Speaking from experience, tren will crush your cardio in a very short time. I used it through college ball and just always thought my cardiovascular sucked due to my size. Nay I say to you, twas the fina.
Quite a few drugs have the potential to decrease certain kinds performance. Heavily aromatizing steroids can cause high BP which can cause pulmonary edema. That can kill your endurance.
You have to be mindful about what you take and how you take it--including ancillaries--if you want to become better across the board.