Joggers getting up early and running through the park, executives trying to work off stress with a game of squash, and people doing bodybuilding may all be shortening their lives. According to Peter Axt, a German researcher and ex-marathon runner, laziness is good for you. ‘No top sportsman’, says Axt, ‘has lived to a very advanced age.’ Among the examples of athletes who have died young, he mentions Jim Fixx, the author of The Complete Book of Running, and the man who almost single-handedl...