Sherlock Holmes was a man who seldom took exercise for exercise's sake. Few men were capable of greater muscular effort, and he was undoubtedly one of the finest boxers of his weight that I have ever seen; but he looked upon aimless bodily exertion as a waste of energy, and he seldom bestirred himself save where there was some professional object to be served. Then he was absolutely untiring and indefatigable. That he should have kept himself in training under such circumstances is remarkable, but his diet was usually of the sparest, and his habits were simple to the verge of austerity. Save for the occasional use of cocaine, he had no vices, and he only turned to the drug as a protest against the monotony of existence when cases were scanty and the papers uninteresting.