Theoretically? Hard to say.
Real world? American Football. The NFL is the only athletic league with 6'8", 350lbs monsters who can still run down the vast majority of people. It's just simple physics; no one will hit you harder than a defensive or offensive lineman - or a linebacker (who weighs 1/3 less but travels 50% faster). Now imagine these people colliding with each other hundreds of times per game - and realize that their actual skin, organs, and bones are no stronger than yours.
Real world? American Football. The NFL is the only athletic league with 6'8", 350lbs monsters who can still run down the vast majority of people. It's just simple physics; no one will hit you harder than a defensive or offensive lineman - or a linebacker (who weighs 1/3 less but travels 50% faster). Now imagine these people colliding with each other hundreds of times per game - and realize that their actual skin, organs, and bones are no stronger than yours.