He can speak with legitimate authority on diet, exercise, martial arts, and other similar topics. He knows more about those things than 99% of people. The point

He can speak with legitimate authority on diet, exercise, martial arts, and other similar topics. He knows more about those things than 99% of people. The point is he doesn't claim authority on topics related to politics and science where he's out of his depth, or at least does it a lot less often than typical partisan commentators. You seem to be reading a different definition than I am, but ok /shrug.