Many accuse Landis of seeking revenge amid bitterness that he was singled out for doping in a sport that for many years tolerated, if not condoned, systemic drug use. Armstrong has also called into question the credibility of Landis, who recently admitted lying about his own doping in an autobiographical book and in arbitration hearings over the failed drug test that stripped him of his 2006 Tour de France crown.
In a statement after the most recent Landis allegations, Armstrong said that he had too much work to do in his “continued fight against cancer” to reply to the charges – a tactic he's frequently used to deflect criticism.
“This has been a constant thing with him, anytime he comes under pressure he takes out the cancer flag,” says Paul Kimmage, a sports journalist for the Sunday Times in London.
But Armstrong rarely finds himself on the defensive; he has worked hard to proactively control his image in the media.
He’s limited media access to the point where reporters regularly rely on his Twitter feed for quotes. He has also punished disloyalty from former teammates and associates.
“There’s a very harsh price to pay [for speaking against him] because of his power within the sport,” says Mr. Kimmage, a former professional cyclist who revealed his own doping experiences in the book Rough Ride.
When negative stories have been published, he’s responded quickly and harshly.
In 2005, French newspaper L’Équipe accused Armstrong of using the banned drug EPO in the 1999 Tour de France.
The paper reported that France's Châtenay-Malabry antidoping laboratory, which is accredited by the World Anti-Doping Agency, had decided to retest samples from 1999 after developing an EPO test in 2000. Of twelve samples analyzed, six were Armstrong's and showed EPO use, the paper reported. It ran an in-depth feature, quoting lab director Jacques de Ceaurriz as saying that there was "no possible doubt as to the validity of the results."