Blood transfusions have long been the only available care for people with anemia due to kidney disease. In the long run it is both troublesome and dangerous. Over time, elevated iron levels can damage the body's organs.

The discovery of the hormone erythropoietin (epo) led to an alternative treatment. The substance strengthens the body's own production of the red blood cells needed to transport oxygen from the lungs to the rest of the body.

Sports had a new problem

"I realized immediately that it was wonderful for the patients - and at the same time that we had a new problem in sports," says Arne Ljungqvist, a doping physician with a past position as a member of the International Olympic Committee and chairman of the World Anti-Doping Agency (WADA).

He was worried. During the 1988 Winter Olympics in Calgary, Canada, he raised the issue of doping with colleagues. It was obvious that an athlete could increase their oxygen uptake capacity by taking syringes with epo. The problem was that there was no way to detect that kind of cheating.

Cyclists though

In the early 1990s, Arne Ljungqvist suspected that cyclists actually doped with epo.

- Professional cyclists have always been inclined to try to find their own cocktails to dope with. And several young healthy cyclists died suddenly of blood clots, he says.

Slightly high doses of the early epo preparations involved a significantly increased risk of blood clots.

Johann Mühlegg got stuck

A breakthrough in the pursuit of cheating athletes came in 1995. Then, Leif Wide, a biochemist at Uppsala University, found a way to distinguish artificial variants of the epo from the body.

In the Olympic context, the test was used for the first time in 2002 during the Winter Games in Salt Lake City, USA. The test proved positive for two Russian skiers and for the Spanish-German ski king Johann Mühlegg, who easily sprinted from Swedish Per Elofsson. Johann Mühlegg was later disqualified and removed his medals.

- Today the test method has been tried and tested. It is an expensive but effective way to expose cheaters, says Arne Ljungqvist.