Britain's 2010 Winter Olympic gold medallist Amy Williams has announced her immediate retirement from skeleton.
The 29-year-old had been struggling with injury and form and quits two years after her victory in Vancouver.
Williams said it had been a hard decision to make but added: "My injuries have been causing me a lot of pain.
"I ruptured my knee a week ago. It has got to the point where it is not really much fun any more."
She added: "I feel it is now time for me to see what other challenges lie ahead.
"I am extremely proud to have represented my country and have enjoyed every moment."
Speaking to the BBC, Williams admitted: "I'm not sure what I'll do next. I'd love to do adventure challenge TV work and use that craziness that you need in our sport.
"I'm going to dive into the London Olympics because I'm one of the ambassadors for that.
"Enough is enough after a while. I still want to have a fit body to do other things in life."
Williams was the only medallist for Team GB at the 2010 Games, breaking the track record twice to win by half a second from Germany's Kerstin Szymkowiak.
In doing so she became Britain's first solo Winter Olympic gold medallist since ice skater Robin Cousins in 1980.
She said: "I'll never forget that moment when I won the gold medal, 10 years of training got me there. I sometimes like to think I'd do it all over again, but I know I need to move on."
After winning gold, Williams returned to Bath a national heroine but, after taking time out from her sport the following season because of her new-found fame, which included taking part in television programmes 71 Degrees North and Alone in the Wild, she admitted the hunger and desire to compete at the top level had gone because she had already achieved the ultimate prize.
Williams, awarded an MBE in 2010, did return to the World Cup scene but found her British team-mates, 2006 silver medallist and current World Cup champion Shelley Rudman and Lizzy Yarnold, continually outperforming her.
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.
"After achieving my lifetime goal of winning an Olympic gold medal, I feel the time is right that I make way for the next generation of athletes to come through."
Skeleton is one of Britain's most successful Winter Olympic sports after winning medals at the last three Games.
Rudman is the current World Cup champion while Yarnold is the junior World Champion, won a bronze medal at the World Championships this year, and two World Cup races in her first year on the senior circuit.
The 2014 Winter Olympics will take place in Sochi, Russia.