I can't put this into words properly cos' I'm not right clever but to use a slightly related analogy, if you look at pit dogs, the ones that train for muscle mass with resistance training ie heavy reps such as weight pull and even to a certain extent pulling hard on a lead, build more mass, same as in humans. Heavy weight, short reps and your mass increases as you are pushing more volume of blood through the capillaries. For endurance and stamina you'd do the exact opposite ie lighter weights for a longer time.
To get back to the pit dog analogy, the muscle bound dog needs more oxygen to f