About doping in professional sports, especially cycling, Dr. San Millán has pointed out that no sport is more carefully surveyed than cycling, and that the more you test, the more you catch, so the sport will look "dirtier."
He has said: "Imagine here in Denver, there's an alcohol test at every traffic light, and there could even be random tests even before you put your key in the car, boom, there's the police there to test you. In absolute numbers Denver would be the city with the highest index of drunk drivers in the world. Imagine on the other side, in New York City, there's only two policemen, two traffic lights, and everybody knows where they are. In raw numbers, New York's positive numbers would pretty much be zero. At the end of the day, you'd be much safer driving here in Denver because there's so much control compared to New York.
That's pretty much what happens in sports. We hear about more doping cases in cycling just because they do so much more with the tests. We see in other sports they either never test for foreign substances, or they test for only a few substances, so you don't see the whole picture there. Many people miss the whole picture there. The statistics for doping in cycling are probably the lowest in sports. They do about 10,000 tests per year and we only see only 4 or 5 cases per year. So we're talking .04-.05%." While a number of his former employers have been beset by doping scandals, San Millán is widely regarded as an exponent of a clean cycling.