The man who oversaw the Lance Armstrong doping investigation has called the disgraced cyclist's confession a step in the right direction.
US Anti-Doping Agency chief executive Travis Tygart said Armstrong now must give more formal evidence about his doping past.
Reaction to Armstrong's much-anticipated interview with talk show host Oprah Winfrey was as wide and varied as the opinions of him have always been.
There was fascination, great sadness, indifference and revulsion.
Tygart was matter-of-fact.
Armstrong once called the USADA investigation that Tygart oversaw into his cycling career a "witch-hunt" but chose not to contest its exhaustive report when it was published last August.
The Texan was stripped of his record seven Tour de France titles, his Olympic bronze medal from 2000 and banned from all sanctioned sport for life.
"If he is sincere in his desire to correct his past mistakes, he will testify under oath about the full extent of his doping activities," Tygart said in a statement.
Retired Australian Tour de France star Robbie McEwen, who organised charity rides with Armstrong in this country only a couple of years ago, said he felt deceived.
"It's changed everyone's opinion of him," McEwen said of the confession.
"Everyone wanted to believe in the hero, the fairytale story.
"I don't think there's a person on the planet who even remotely follows cycling who hasn't changed their opinion of what we thought Lance was."
Fellow Australian cycling great Stuart O'Grady was among those who stressed the sport had changed since Armstrong's Tour reign.
"The damage has been done, there's no getting around that," O'Grady said.
"But what we can do now is look to the future."
Phil Liggett, the veteran commentator nicknamed the voice of cycling, was another prominent figure who used to strongly support Armstrong.
"It was not a deep and sincere apology if that's what we were looking for," Liggett said.
"He has to name names.
"He doesn't seem to realise the incredulous crime he's committed."
Businessman Jaimie Fuller is a key figure in Change Cycling Now, a group established in the wake of the Armstrong scandal that wants an overhaul of the sport's top levels.
"My expectations were very low and I've been pleasantly surprised," he said.
"The whole thing was in the last five minutes, where he said if there is a truth and reconciliation, I will be the first person through the door.
"It just shows the importance of that process and the frustration we have ... that the UCI continue to block that."
Cycling's world body is in the midst of an argument about whether there should be a truth and reconciliation process for the sport.
UCI president Pat McQuaid said in a statement that Armstrong's interview was disturbing.
"Armstrong also rightly said that cycling is a completely different sport today than it was 10 years ago," McQuaid added.
"In particular the UCI's introduction of the biological passport in 2008 - the first sports federation to do so - has made a real difference in the fight against doping.
"Finally, we note that Lance Armstrong expressed a wish to participate in a truth and reconciliation process, which we would welcome."
Livestrong, the cancer charity that Armstrong founded, said it was "disappointed" that he had cheated.
Australia's Tour de France pioneer Phil Anderson, a teammate of Armstrong's in the early 1990s, said the interview had not told him much new.
"I don't think anything was really revealed, beyond what had been leaked," Anderson said.
"Finally we hear it from him.
"You look at his body language, he doesn't look any different to his usual interview."
Betsy Andreu, the wife of Armstrong's former teammate Frankie Andreu and one of the first to publicly accuse the Texan of doping, agreed.
"I'm really disappointed," Andreu, who was repeatedly attacked by Armstrong over the years, told CNN.
"After what you've done to me, what you've done to my family and you couldn't own up to it. And now we're supposed to believe you?" she said.
ABC television presenter Leigh Sales didn't hold back: "I've watched enough. That was depressing. I've rarely seen such a soulless psychopath," she tweeted.