Commonly referred to as "doping", one of the biggest problems in modern sports is the use of performance enhancing drugs. As you might imagine, the organisations that regulate major competitions take a dim view of this kind of behaviour; taking a drug to build your muscle growth or to give you a boost of energy is hardly fair competition after all.

Even if you take the view that doping is no more of a threat to fair competition than high-technology materials in sports clothing and equipment, performance enhancing drugs can present a substantial threat to health in both the long term and the short term. With the pressure of competition, it's not unknown for athletes to cause major damage to their health in a bid to go beyond the limits of natural endurance and performance.

It took a little while for public opinion and sporting bodies to take a stance against drug use in sports though. In the 19th century and early 20th century, the practice wasn't something swept under the carpet - it was openly used. As incongruous as it might seem, they were even used in endurance walking races - one contestant in an 1807 race openly used laudanum to stay awake for upwards of 24 hours.

It was the widespread use of nitroglycerine - the drug used to stimulate the hearts of cardiac arrest victims - in the bicycle races of Europe and America that put 'doping' out of fashion though. Although the drug kept the riders alert and active beyond the limits of human endurance, the side effects were fairly disruptive.

One champion of the American circuit, Major Taylor, was unable to finish a race in New York because of the hallucinations his drug use and sheer exhaustion had caused. As he put it, "I cannot go with safety, for there is a man chasing me around the ring with a knife in his hand.''

Although few cases of doping have had such dramatic effects as this case, almost every major sporting body has implemented a drug testing programme for competitive events in the wake of the public backlash against this kind of activity. The first was the International Association of Athletics Federations, who banned the practice in 1928 - even though they lacked any kind of drug testing kit and had to rely upon good sportsman ship and an honest word. It took decades but eventually the policy was adopted by FIFA, the Union Cycliste Internationale and the International Olympic Committee in 1966.

Ever since there has been an ongoing battle between pharmaceutical science on one side of the doping divide and advances on the other. Drug designers keep trying to find workarounds for detection methods whilst the authorities and the more reputable elements of the science world try to find new ways of detecting them.

In 1999, regulatory efforts around the world were combined for the very first time and the Word Anti Doping Agency was founded. Today, drug testing kits are developed to a universal high standard and increasing numbers of athletes are caught in the act.