Oprah: Armstrong 'forthcoming' in interview about drug use Despite denials made in interviews and a deposition, legendary cyclist Lance Armstrong has come clean about using performance-enhancing drugs. NBC's Ann Thompson reports on his admission to Oprah Winfrey. Oprah Winfrey says Lance Armstrong was "forthcoming" in their 2.5 hour interview, a session during which the disgraced cyclist admitted using performance enhancing drugs to win the Tour de France, NBC News has confirmed. "I think the entire interview was difficult" for Armstrong, Winfrey said. He was pretty forthcoming. "It was surprising to me," she said of his approach to the interview, adding that "we were mesmerized and riveted by some of his answers." Winfrey appeared on CBS Tuesday morning to discuss her sit-down with the disgraced cyclist. When asked if Armstrong was contrite, she demurred. "I feel that he answered the questions in a way that he was ready," Winfrey said. I choose not to characterize. I would rather people make their own decisions about whether he was contrite or not. The interview will be aired in full over two nights, Winfrey said. Armstrong, 41, had for more than a decade denied doping. He was stripped of his seven Tour de France titles earlier this year, and was banned for life from competing in Olympic sports after a scathing 1,000-page report by the United States Anti-Doping Agency. "I have never doped," Armstrong said in a 2005 interview with Larry King. I can say it again ... but I've said it for seven years. It doesn't help. Those years of denial followed him to a Four Seasons hotel in Austin, Texas, where Armstrong, accompanied by friends and family, sat down for his revelatory interview with Winfrey. Armstrong shared a personal apology on Monday with staffers at the Livestrong charity he founded, Livestrong director of communications and external affairs Rae Bazzarre confirmed in a statement to NBCNews.com "Lance came to the Livestrong Foundation's headquarters today for a private conversation with our staff and offered a sincere and heartfelt apology for the stress they've endured because of him and urged them to keep up their great work fighting for people affected by cancer," Bazzarre said in the statement. As news of Armstrong's admission emerged, critics blasted the one-time role model on Tuesday. New York Daily News columnist Mike Lupica talks about Armstrong's revelation that he did take performance-enhancing drugs after years of denials, calling it a "giant athletic Ponzi scheme," and attorney Lisa Bloom discusses the legal implications. People just fell in love with the legend. They like that story better than the reality," columnist Mike Lupica said on TODAY. Most reasonable people think that ... this is like an announcement saying that the ocean is deep. "I believe that he's completely insincere except for this," Lupica said. He is starting to repair his own brand. People have overlooked the real story here - lives that had to be destroyed to keep the lie going. To me this is like some giant, athletic Ponzi scheme that went on and on and built and built. Depending on the precise nature and scope of Armstrong's admissions, he could be subject to defamation charges as well as suits from former sponsors seeking to recoup some of his fortune, attorney Lisa Bloom told TODAY. Armstrong has been reported to be worth as much as $100 million. "This could keep lawyers in business for many, many years," Bloom said. I'm sure that all of his attorney were against it. Legally, confession is a bad thing to do. Morally, it's a fabulous thing to do. Despite the controversy over his use of performance-enhancers, Armstrong's charity work is still drawing praise from some. ESPN anchor Stuart Scott tweeted on Monday that he remains "grateful" as "1 of millions of (cancer) survivors he's helped." The full interview with Armstrong, which Winfrey taped Monday, will air on her OWN network starting on Thursday evening. Just wrapped up with @lancearmstrong More than 2 ½ hours. Winfrey tweeted after the taping. She said Tuesday it was the "biggest" interview she has ever done in terms of exposure.