No other cyclist has won as many Tour de France titles as Armstrong
Seven-time Tour de France winner Lance Armstrong has confirmed he has retired from competitive cycling for good.
The American, 39, retired from cycling in 2005 but returned for the 2009 Tour, where he finished in third place behind winner Alberto Contador.
"I can't say I have any regrets. It's been an excellent ride," he said.
Armstrong is facing a US federal investigation into allegations of doping after former team-mate Floyd Landis claimed he used banned drugs.
The investigation is examining whether Armstrong used government money to dope and win his seven Tours while riding with the now-disbanded US Postal team.
It follows allegations made by Landis, who was stripped of the 2006 Tour de France title following a positive drugs test.
But Armstrong, who has never tested positive for performance-enhancing drugs, has consistently denied the allegations.
His contribution to cycling has been enormous, from both the sporting point of view and his personality
UCI president Pat McQuaid
"I can't control what goes on in regards to the investigation," said the Texan. "That's why I hire people to help me with that. I try not to let it bother me and just keep rolling right along. I know what I know.
"I know what I do and I know what I did. That's not going to change."
Armstrong finished in 67th place in his final competitive race of his career in last month's Tour Down Under in Australia, finishing six minutes and 42 seconds behind race winner Cameron Meyer.
In 1996 Armstrong had been given less than a 50-50 chance of survival after being diagnosed with testicular cancer as the disease spread to his lungs and brain.
However, after an aggressive bout of chemotherapy, he made a full recovery and returned to the sport in early 1998, going on to dominate the race from 1999 to 2005.
He set up the Livestrong cancer charity which gained international recognition as the organisation's distinctive yellow wristbands were worn by millions of people worldwide.
Last year he rode for the Astana team but after a public dispute with team-mate Alberto Contador he left to form his own team, backed by American retailer RadioShack, finishing the blue riband race in 23rd place.
"I have no regrets about last year either," added Armstrong. "The crashes, the problems with the bike - those were things that were beyond my control."
Armstrong remains the only rider in the history of cycling to win the Tour de France on seven different occasions.
"His contribution to cycling has been enormous, from both the sporting point of view and his personality," said International Cycling Union president Pat McQuaid.
"All sports need global icons and he has become a global icon for cycling. The sport of cycling has a lot to be thankful for because of Lance Armstrong."