According to the World Anti-Doping Agency (WADA)’s 2005 report, the sport of cycling produced the most failed drug tests of any Olympic sport. With 3.78% tests being positive, cycling just edged out baseball (3.69%) with boxing and triathlon tied for third (3.41%).

Cycling has the dubious honor of having not only the highest percentage but also the most positive tests - 482 out of 12,751 combined samples for both road racers and mountain bikers.