If you want to run fast, EQ is your steroid of choice. I would stack it with cardarine/cardazol for max cardio boost.
400mgs EQ + 20mgs cardarine + 20 cardazol (2cap)
500-600 mgs of eq is where like it at but it has no comparison to gw50516 when it comes to increasing endurance.. you would be far better off just stacking gw501516 and sr9009