Chess Boxing is a real sport and one that combines the physical strength of boxing and mental fortitude of chess.
"Fighters" battle through alternating rounds of both boxing and chess and the only ways to win are through knockout, checkmating your opponent, referees decision or if your opponent exceeds the chess time limit.
I think it would actually be quite fascinating to watch despite not being nearly that popular.
Check out the video below to see a bit about the world of chess boxing.
Thanks to Bleacher Report for sharing!