Performance-enhancing drug image

Performance-enhancing drugs

Explore current and future scenarios around controlled substances in sport

Now: Erythropoietin (EPO)

Some competitive cyclists have abused the hormone erythropoietin (EPO), which increases the production of red blood cells and allows them to transport oxygen more easily. The effect is similar to the adaptation seen in people who live at high altitudes, with reduced air pressure. Indeed, some athletes train at altitude for this reason, a practice that is not banned. The use of EPO in endurance sports is banned, but manufactured forms of the hormone are very similar to the naturally occurring chemical and were hard to detect until the turn of the century.

Now: Biological passports

In 2014, there were 46 athletes in the UK serving bans from sport following doping scandals. To combat this and to try to conquer the culture surrounding the use of performance-enhancing drugs, the biological passport was introduced. It was first used in cycling.

Previously, drug tests looked for specific compounds, and so were easily deceived by taking different isomers of substances or other similar but undetectable drugs. The biological passport instead involves regularly testing the blood of elite athletes to establish, on an individual basis, what their normal blood values are, and then looking for anomalies caused by taking performance-enhancing drugs.

The passport also allows for doping accidents to be fairly dealt with, as it makes it easy to isolate cases where someone has doped on a one-off occasion, rather than regularly or at crucial times prior to competition. Athletes with a clean record may also be able to use the passport to avoid unfair speculation and negative media attention. Athletics, football and tennis have all introduced biological passports now, and more sports are looking to incorporate them.

Future: Gene doping

Gene doping is the non-therapeutic manipulation of genes to improve athletic performance, and the first documented case of gene doping was in 2008. It involved a product called Repoxygen, which boosted EPO levels. If muscles can be tweaked genetically so that more EPO is produced, and the extra EPO is identical to that produced normally, then theoretically the products of this sort of doping are undetectable. Gene doping is therefore a growing challenge to sports, and the World Anti-Doping Association is devoting “significant resources and attention” to its detection.


About this resource

This resource was first published in ‘Exercise, Energy and Movement’ in January 2012 and reviewed and updated in August 2016.

Genetics and genomics, Physiology, Medicine, Health, infection and disease
Exercise, Energy and Movement
Education levels:
14–16, 16–19, Continuing professional development