Under the Microscope: Performance-enhancing drugs are, apparently, widespread in top-level sport, whose regulatory bodies combat them with extensive testing programmes, writes Prof William Reville.
Offenders are probably always one step ahead, however, as the current experience with the anabolic steroid THG illustrates. In top-class sport, where the monetary and social rewards of success are so great, it seems certain that drug enhancement will remain with us for a long time. Malcolm Gladwell wrote a fine essay on drugs in sport in The New Yorker in September 2001.
The use of drugs in sport probably reached its low point in the cynical practices of the East German regime for the couple of decades before it fell, in 1989. The cream of young East German athletes were put on training programmes that included the systematic ingestion of performance-enhancing drugs. These produced impressive results on the sporting field, but in many cases, particularly in girls, they reaped havoc with health. A teenage girl naturally produces about 0.5 milligrams of testosterone a day, for example, but the East Germans administered them with up to 35 milligrams a day. In many cases this gross abuse led to complications ranging from masculinised physiques to depression, cancers and deformed babies.
Most people are familiar with the term anabolic steroids. These chemicals build up muscle mass; the best known example is the male sex hormone testosterone. Taking this drug doesn't directly produce better sporting performance, but it does so indirectly by allowing athletes to train harder. Hard training stresses the body and releases hormones that tend to break down muscle. Ingesting testosterone counteracts this effect, allowing the body to recover more quickly and the athlete to train much harder.
The International Olympic Committee (IOC) decided to move against testosterone supplements in the early 1980s. As males produce testosterone naturally, and as some males produce more than others, a test was devised to compare the level of testosterone in the urine with that of another hormone, epitestosterone (the T/E ratio), rather than to measure absolute levels of testosterone. For most adults, the T/E ratio is one to one. If you have been taking testosterone supplements, however, the ratio will be much higher. The IOC set the legal limit at six to one in order to take into account people who have naturally high levels of testosterone.
Until the mid-1990s most drug tests were carried out at major competitions. This allowed athletes on testosterone supplements to fool the testers simply by going off the supplements in the weeks before the competition. The authorities countered by randomly testing at training sites or athletes' homes. Cheating athletes responded by taking epitestosterone supplements in addition to testosterone, thereby maintaining the T/E ratio below the six to one limit. The authorities countered by independently measuring epitestosterone levels.
One recent ruse adopted by cheating athletes is to apply testosterone patches to the skin. These administer a continuous low dose of the hormone, but once the patch is taken off the testosterone level can drop to normal in less than an hour. Athletes can monitor how long this takes; then, when the tester arrives, they can fool the system by stalling while the level drops. Athletes can also take drugs for which no test has yet been developed.
Energy-giving oxygen is carried from the lungs to the muscles by red blood cells. Erythropoietin (EPO) is a hormone produced in the kidneys that stimulates production of the cells. EPO is administered to patients with low blood-cell counts, such as those undergoing chemotherapy. EPO is very popular with endurance athletes, particularly cyclists, as it can increase the amount of oxygen the blood carries to muscles, thereby postponing fatigue.
The proportion of blood volume taken up by red blood cells is called the haematocrit. The average haematocrit for an adult male is between 38 and 44 per cent. In 1995 the authorities announced that any cyclist with a haematocrit above 50 per cent would be suspended. The figure was chosen to protect athletes with naturally high haematocrits.
Although increasing the number of red blood cells enhances endurance, there are serious health risks. If there are too many red cells the blood becomes heavy and sluggish, putting a huge strain on the heart. Up to 20 professional cyclists died in the late 1980s under circumstances that suggested EPO overdose. The 50 per cent haematocrit limit is below the danger level.
The authorities have developed sophisticated tests to determine if athletes have used EPO recently. But as they develop such tests, the wealthiest athletes turn their attentions towards synthetic oxygen-carrying chemicals for which no tests have yet been developed.
My main problem with drugs in sport is simply that it is not sport. Sport is the competition between natural talents nurtured in natural ways. When two such athletes compete, the winning performance can be credited to a narrow human spectrum of causes, but mainly to natural talent nurtured by natural effort. When two drug-enhanced athletes compete, the winning performance may have more to do with the ingenuity of the winner's chemist than with the natural talents of the winner.
William Reville is associate professor of biochemistry and director of microscopy at University College Cork