I was wondering. I see these long distance runners and they are mostly very skinny, and then I see these sprinters and they are very well built and cut. Why is this? Does long distance running cut back on your lean muscle tissue?
*Another Question is: If I want to build up my calves/legs, is it better to do stair climbing cardio for 10-15 min or running on the cardio machine for 10-15 min; What are the pros and cons of these two? :withstupi