Chess Boxing seems to be getting a lot of attention lately. The basic premise of this sport is that you play chess for four minutes, and then you box for two minutes. Then you go back to playing chess, followed by another round of boxing. And this goes on and on for eleven rounds until someone is either knocked out, or checkmated. The website of the World Chess Boxing Organization states that:

One of the goals of this new sport is the old ideal of a healthy mind in a healthy body: mens sana in corpore sano. During a chessboxing fight the control of aggression plays a big role. That's why WCBO's motto is: "Fighting is done in the ring and wars are waged on the board".

A search of news articles about chess boxing confirms that this is, indeed, a real sport. Though it may be a while before it gets included in the Olympics. The Wikipedia article about Chess Boxing provides this history of the sport:

The concept was invented in 1992 by cartoonist Enki Bilal, and a match of chess boxing was a major plot point of his graphic novel Froid-Équateur. Iepe "the Joker" Rubingh, a Dutch artist, inspired by Bilal's book, brought the concept to life in the spring of 2003... The first world championship was held in Amsterdam in 2003 and was won by Iepe Rubingh himself. The 1st European Chess Boxing Championship took place in Berlin on 1 October 2005 when Tihomir Titschko of Bulgaria defeated Andreas Schneider of Germany after the latter conceded defeat in the seventh round.

(via The Presurfer)