Amy Williams has announced her retirement from skeleton with immediate effect, bringing an end to a career which famously culminated in a Winter Olympic gold medal in Vancouver in 2010.
The 29-year-old Williams said it took "guts and bravery" to reach her decision not to pursue a second gold in Sochi in two years' time, after two post-Games seasons badly hit by injuries.
Williams told the Press Association: "My injuries have been causing me a lot of pain and I ruptured my knee a week ago. It has got to the point where it is not really much fun any more."
Williams became Great Britain's first individual female gold medallist at a Winter Games in 58 years when she produced four near flawless runs on the Whistler track to triumph by over half a second.
It was a victory given added poignancy by the death of the Georgian luger Nodar Kumaritashvili on the same track less than two weeks earlier. While others hesitated, Williams stormed through to victory.
She added: "I told myself after Vancouver that I would have a little break then get back on the ice and compete again, because there is still nothing I love more than getting on my sled and going down the track.
"I'm still convinced I could have gone to Sochi and won another medal, but it would take an awful lot of sacrifices and it has just come to the point where my body is screaming at me to stop.
"It is easy for an athlete to stay in their comfort zone, but it takes a bit of guts and bravery to step outside it and find another challenge in life. I am happy and content with what I have achieved in my sport."
Despite heading to Vancouver as British number two behind Turin silver medallist and rival Shelley Rudman, Williams had shown promise when winning a World Championship silver on the same Whistler track in 2009.
Her remarkable victory - in which she broke the track record in her opening run and maintained her advantage to the end - resulted in a whirl of publicity opportunities and an MBE, as well as being appointed an ambassador for this year's London Games.