Synthetic EPO is banned in sport. It drastically improves oxygen delivery to muscles and is used illegally by endurance athletes. Lance Armstrong admitted to using synthetic EPO during his Tour de France successes.
In the lead up to Mountain Bike Cross Country World Championships in Vallnord, Andorra, at the end of August 2015, SAIDS authorised its Spanish counterparts to conduct drug testing on the South African cycling team preparing for the international competition. Of the South African athletes tested in Andorra, only Croeser’s sample was found to contain Recombinant EPO.