He met with United States Anti-Doping Agency officials, including Travis Tygart, the agency’s chief executive, last month to discuss what he needed to do to mitigate his ban. Several people with knowledge of the discussions said Tygart would be willing to reduce Armstrong’s punishment if Armstrong would testify against the people who helped him dope. That would possibly include Pat McQuaid, the president of the cycling union, and Hein Verbruggen, who was the cycling union’s president from 1991 to 2005, a time when doping in the sport was rampant. Verbruggen, who is close with the International Olympic Committee president, Jacques Rogge, is also the cycling union’s honorary president and an honorary member of the I.O.C.

David Howman, director general of the World Anti-Doping Agency, said in a telephone interview Monday that he would not believe that Armstrong would testify in other cases to help clean up the sport until it happens.

“This guy is an enigma and nobody really knows what he is going to do, no matter what he says,” Howman said. “I think he’s got his own demons to deal with, but nothing can be done about his lifetime ban when he hasn’t done anything to help us yet.”

Last fall the United States Anti-Doping Agency called Armstrong the kingpin of the doping program on his Tour de France winning teams when it made public evidence that he had doped and had encouraged his teammates to dope. During his interview with Winfrey, Armstrong rebutted the claim that he was a leader of the doping program, saying he just did what his teammates were doing, according to the two people who did not want their names published because they are not authorized to speak about the interview.

Before heading to the Winfrey interview in downtown Austin, Armstrong stopped at the headquarters of his cancer charity, Livestrong, and apologized to the staff. He told them he was sorry for letting everyone down and for putting so much stress on the organization because of his doping scandal.

He did not confess to using performance-enhancing drugs, but spoke for about 20 minutes in the organization’s boardroom, eliciting tears from some of the employees, said Rae Bazzarre, a spokeswoman for Livestrong.

“It was emotional and he choked up for a moment,” she said. “But we were all glad to see him.”

Armstrong had not been at the headquarters since Oct. 21, Bazzarre said, about two weeks before he resigned from Livestrong’s board of directors.