This time next year the 2016 Olympic Games will be in full swing in Rio. Whatever surprises the sport may throw up, one issue is bound to be in the headlines: doping. Even this summer alleged cheating by taking performance-enhancing drugs has rarely been out of the news. The latest furore surrounds hundreds of blood tests leaked from the database of the International Association of Athletics Federations, which some experts claim are evidence of widespread doping.

Underlying the whole debate is a misplaced sense of moral outrage — a feeling that sport is intrinsically a clean contest between unenhanced athletes, being corrupted by evil drug pushers. The reality is that ever since people began competing for athletic honour and glory they have been willing to improve their speed, strength and accuracy in any way they can. Recently, the growing concentration of money and media attention on elite sports, together with the increasing opportunities to boost performance offered by science, has added to the pressure but not brought fundamental change.

Once we acknowledge that enhancing human capabilities is an integral part of athletic competition, then the authorities in each sport have to lay down rules and decide how to enforce them. First, they have to regulate the external equipment used, from racing cars to racehorses, bicycles to tennis rackets. This is far from straightforward. Usually, the aim is to smooth out the introduction of new technology, so competitors do not suddenly gain access to something markedly superior that would unbalance the contest.