Will running 400 meters lose muscle mass or gain some muscle?

Question

like is it a good way to build leg muscle

Answer 1

h**l yea dude! try doing 3 500m one after the other with only a 300m walk recovery and then doing another 3 500m only having 5 mins break between the two sets. now thats really hurts.

Answer 2

gain.

weight machine better for building muscle.

Answer 3

It will help you gain muscle mass. In technicle terms it does decrease muscle mass but then the tissue rebuilds itself bigger.