AUSTIN, Texas (AP) -- A person familiar with the situation says Lance Armstrong confessed to Oprah Winfrey during an interview Monday that he used performance-enhancing drugs to win the Tour de France.

The person spoke on condition of anonymity because the interview is to be broadcast Thursday on Winfrey's network.

Armstrong was stripped of all seven Tour titles last year in the wake of a voluminous U.S. Anti-Doping Agency report that portrayed him as a ruthless competitor, willing to go to any lengths to win the prestigious race. USADA chief executive Travis Tygart labeled the doping regimen allegedly carried out by the U.S. Postal Service team that Armstrong once led, "The most sophisticated, professionalized and successful doping program that sport has ever seen."

After a federal investigation of the cyclist was dropped without charges being brought last year, USADA stepped in with an investigation of its own. The agency deposed 11 former teammates and accused Armstrong of masterminding a complex and brazen drug program that included steroids, blood boosters and a range

Oprah Winfrey said today that disgraced cyclist Lance Armstrong came well prepared for their highly anticipated interview, although he "did not come clean in the manner [she] expected."

Winfrey, who discussed the interview on "CBS This Morning" today, said, "We were mesmerized and riveted by some of his answers. I feel that he answered the questions in a way that he was ready. … He certainly had prepared himself for this moment. … He brought it. He really did."

Armstrong had apologized to staffers at the Livestrong Foundation before the Monday interview with Winfrey at a hotel in Austin, Texas, and reportedly admitted to them that he used performance-enhancing drugs throughout his storied career.

Armstrong also confessed to Winfrey to using the drugs, sources have told ABC News. Winfrey said this morning that the entire interview, for which she had prepared 112 questions, was difficult.

"I would say there were a couple of times where he was emotional," she said. "But that doesn't describe the intensity at times."

As for the cyclist's sense of remorse, Winfrey said that will be for viewers to decide. "I would rather people make their own decisions about whether he was contrite or not," she said.

The interview will air on the OWN network for two nights, starting at 9 p.m. ET Thursday and continuing Friday.

BOULDER, Colorado (VN) — A game that was once painfully slow and perfectly managed by Lance Armstrong is now at warp speed, and it seems the fallen champion finds himself on more unstable sporting and legal grounds than ever before.

Armstrong’s public confession — taped with Oprah Winfrey on Monday in Austin, Texas — is coming on Thursday night in front of an international television and online audience. The move to confess in the taped interview was seen as yet another tactical maneuver by a man as calculating off the bike as he was on it. But his famous control appears to be unraveling, as media reports exploded late Monday, sketching an unfamiliar scene for Armstrong, one of loss of control and increasing velocity.

Armstrong famously won the Tour de France seven times and was infamously stripped of those wins last fall after the U.S. Anti-Doping Agency loosed a 1,000-page report chronicling systemic performance enhancing drug use at the U.S. Postal Service team.

Throughout his career, Armstrong has been able to exert unbelievable control over the media and the flow of information. Even when under investigation by the U.S. Attorney’s Office, he was able to merge his legal and public relations strategies to weave a narrative that he was treated unfairly by the government, liberally using the “#unconstitutional” hashtag on Twitter to imply an unfair — and even illegal — fight. The feds didn’t see it that way, of course, but they did walk from a two-year investigation on a Friday night without a whimper.

His power seemed as firm as his denials. But the game has changed, and quickly. The Wall Street Journal reported Monday night that Armstrong’s legal team was negotiating a settlement with former teammate Floyd Landis, who filed a whistleblower suit on the grounds that public money was used to buy doping products while Armstrong raced for U.S. Postal. Armstrong could be on the hook for as much as $100 million in that case — three times what the Postal Service paid the team. The Department of Justice reportedly has until Thursday — the day of the interview broadcast — to decide whether or not it will join the suit. The department recommended on Monday that federal attorneys pursue the case, according to a CBS News/Associated Press report.

Another element of that story? Armstrong may even testify against others involved in doping activities — something that seemed unthinkable as recently as October. Armstrong’s denial machine fought off accusations for a decade, but now he feels compelled to drag others into the muck with him. But who’s left to line up?

The New York Times reported on Monday that Armstrong was considering testifying against UCI officials and former Postal Service team owner Thomas Weisel and other Postal cycling team officials.

Confessions, or even plea bargains, generally come when one party knows the outcome of the confession, otherwise there is no incentive to tell the truth. The Wall Street Journal reported that USADA CEO Travis Tygart told Armstrong it was too late to come clean with the perks of an effective plea bargain, and that the minimum he could hope for was an eight-year ban rather than the lifetime barring he’s currently saddled with — an effective death knell for his endurance career.

It’s all in sharp contrast to the message Armstrong used to send, which was his way or the highway. He would blacklist reporters, including those on VeloNews staff, and even buried Greg LeMond’s bike brand due to LeMond’s suspicion Armstrong used PEDs.

That’s why the current landscape surrounding the fallen champion is remarkable. The ground beneath him is cracking faster than he can run.

Just an example: Should the feds join the Landis suit, the game changes for Armstrong hugely. Rather than fight only Landis in court with a cadre of $1,000-an-hour lawyers, Armstrong would find himself staring down Uncle Sam, and all that goes with him, from manpower to financial resources to an increasingly pessimistic court of public opinion. He’s long called Landis a liar, and now all of the sudden seems keen to settle?

The fact he’s even considering turning on those who’ve long run the show, from the Postal Service to the UCI, indicates a desperation unseen before from a man who just a few months ago tweeted a photo of himself on a couch, beneath a spate of yellow jersey’s, will the simple message, “just layin’ around.”

There is a chance that all of this has been mapped in Armstrong’s inner-circle, that a course of action has been charted and the media is merely ghost-writing a script that’s already been roughed out. But something seems different this time; the veneer is gone, and leaked attempts to settle with Landis and testify against the UCI deviate from the devastating control Armstrong has always craved and always exerted.

What has made the Texan unflappable, both on and off the bike, was his calculation, his ability to intimidate a rival, determine a weakness and ride away. But Armstrong always knew his enemy, and knew where the attacks would come from. He had a run of remarkable luck in France, and when the U.S. Attorney’s office abandoned a deep investigation. Simply, Armstrong never had bad days.

Until now.