PARIS â Chris Froome, the Tour de France winner on Sunday, was being peppered at a recent news conference with questions that furtively nibbled at a bigger issue â have you doped? â when his team director leaped into the fray, fairly bubbling with frustration.  Chris Froome rode away from the competition in Stage 8 on July 6 to claim the leader's yellow jersey in the Tour de France, which he won on Sunday.  âWeâve wracked our brains thinking about ways we can satisfy people and make these questions go away,â said Sir Dave Brailsford, the Sky Procycling team principal. âWhy donât you collectively get organized and you tell me what we could do so you wouldnât have to ask the question?â  Whether one viewed Brailsfordâs offer as cynical or sincere, there was an undeniable truth underlying his point: there really is no hard and fast mechanism by which cyclists can prove that they are not using banned substances. Testers can be fooled. Pledges can be broken.  Even when teams release doping test results and performance data to independent physiologists and journalists, as Sky did last week with information from several of Froomeâs races, no one can say definitively that he was not using a prohibited substance.  There are no perfect tests capable of catching every banned substance every time. Moreover, human physiology is so complex, and medical scienceâs understanding of its bounds so limited, that drawing a line between an exceptional but clean performance and a drug-enhanced performance is a tricky, arguably impossible, proposition.  The sports scientists and the journalists who analyzed Froomeâs data carefully put it this way: the riderâs performances were in the realm of the humanly possible. And that was the best Froome and Sky could hope for.  âBasically, it is to say these performances were very good, strong, clean sporting performances,â Froome said.  Yet no one believes the questions will stop, if only because Froome is capable of exceptional performances â as when he left the Tour field behind on a climb in the Pyrenees, recording speeds and power that rivaled riders in the doping years. Froome himself has acknowledged that as disheartening as they may be, the questions are legitimate in the post-Armstrong era.  Jonathan Vaughters, a former rider who admitted to doping years ago and is now an antidoping evangelist as team manager of Garmin-Sharp, said the sport has lost credibility. Until that changes, he asserts, the top riders will be asked questions that they can never satisfactorily answer.  âIf you took a hypothetical situation where everyone knew that the antidoping controls were 100 percent effective, then these question wouldnât be asked,â Vaughters said in an interview. âAnd it wouldnât be placed on Chris Froome.â  Vaughters argues that the onus for cleaning up the sport's image should not lie with individual riders or even teams, but with its governing body, the International Cycling Union. The union points out that its testing regime has been strengthened significantly, and many critics agree. But those critics, including Vaughters, say the union should take the additional step of ceding responsibility for testing to a fully independent agency. The unionâs president, Pat McQuaid, opposes that idea, but a challenger for leadership of the organization, Brian Cookson, has endorsed it.  Even a change in leadership would only be a start, Vaughters said. âThis is a long war, and this isnât going to resolve itself with one or two definitive actions,â he added. âRe-establishing credibility is incredibly hard. Losing it is easy.â  Like Froome, other riders in the peloton say they understand the skepticism about their performances. But they are also frustrated by their inability to put the questions to rest.  Andrew Talansky, an American rookie on the Tour this year with Garmin-Sharp, said he hopes some middle ground will emerge between blind faith and equally blind skepticism.  âIf you want to look at it with a skeptical eye and say, âO.K., I see a performance that I donât 100 percent believe in,â thatâs fine,â he said, âas long as thereâs room in there for people to eventually see that the performances they are witnessing in the Tour are real.â
Cyclingâs loss of credibility has made it impossible for riders to satisfactorily answer questions about performance enhancing drugs.