Here is the main reaction to US cyclist Lance Armstrong's admission that he took performance-enhancing drugs throughout his career, which helped him win a record seven Tour de France titles:
"His admission that he doped throughout his career is a small step in the right direction. But 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."
- Travis Tygart, head of the US Anti-Doping Agency (USADA).
"Lance Armstrong's decision finally to confront his past is an important step forward on the long road to repairing the damage that has been caused to cycling and to restoring confidence in the sport."
- Pat McQuaid, president of the International Cycling Union (UCI).
"There's nothing new from my point of view. All he did was affirm what the US Anti-Doping Agency had put out in a very substantial and irrefutable judgement some months ago...
"He denied that until this point but there was little doubt he was doing that and all he did was confirm that today in a very controlled manner."
- John Fahey, president of the World Anti-Doping Agency (WADA).
"We at the Livestrong Foundation are disappointed by the news that Lance Armstrong misled people during and after his cycling career, including us. We accepted his apology in order to move on and chart a strong, independent course."
Livestrong, the cancer support charity that Armstrong set up.
"It felt good to hear him admit to doping... When he said he was behaving like a jerk during those years, I thought 'Lance, I could have told you that back then'...
"The more I think about the interview, the more conscious I become of the evasions and non-answers. His truth will come dropping slowly."
David Walsh, Sunday Times journalist sued by Armstrong for alleging he doped, on Twitter @DavidWalshST.
"I'm really disappointed. He owed it to me. You owed it to me, Lance, and you dropped the ball. 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?"
Betsy Andreu, wife of Armstrong's former team-mate Frankie Andreu, on CNN.
"I think it's a disgrace for the sport to have an athlete like this. He cheated the sport. He cheated many people around the world with his career, with his life story...
"It's just not the way to be successful. So I think he should suffer for his lies all these years."
World tennis no.1 Novak Djokovic.