Sir Chris Hoy retires after concern he would not win in Glasgow
Six-time Olympic gold medallist Sir Chris Hoy decided to retire from cycling after using "every last ounce of energy and effort" at London 2012.
The 37-year-old Scot had been expected to compete at the 2014 Commonwealth Games in Glasgow but felt "to go on for another year would be one too far".
Hoy, who won two gold medals in London, also claimed 11 world titles.
He said: "I wanted to get a medal for Scotland. I didn't think I could so wanted someone else to take my place."
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Speaking at a news conference at Murrayfield in Edinburgh, Hoy added: "It is a hard time - it is one moment at the end of your career when you say 'enough is enough'.
"It's a decision that I didn't take lightly and I thought about it very hard. In sport at the highest level you are dealing in the smallest margins and you can tell when you are good but not good enough."
Looking ahead to next year's Commonwealth Games, he said: "Nothing would give me more pleasure than going to Glasgow, but I don't want to be there for the numbers.
"Now it's time for younger riders to experience what it is like to compete in front of a home crowd. I will be there to open it and soak up the experience."
The two gold medals Hoy won in London last summer added to the four he had won in previous Games. His sixth beat rower Sir Steve Redgrave's previous mark of five.
Asked if he was the greatest British Olympian, Hoy said: "To describe the greatest is subjective. To me, in my subjective opinion, Sir Steve Redgrave is the greatest in British history."
British Olympic Association chairman Lord Coe described Hoy as an "icon" and praised his commitment to excellence.
And Sir Dave Brailsford, the performance director of the Great Britain cycling team, said he couldn't speak highly enough of Hoy and his career.
Hoy takes pride in the development the sport has undergone during his career.
"I have been in the sport for 19 years and witnessed how the sport has changed out of all recognition.
Golden Hoy - the gold medals
2012: Team sprint & keirin
2008: Team sprint, keirin & sprint
2004: 1km track time trial
2008: Sprint & keirin
2007: Keirin & 1km time trial
2006: 1km time trial
2005: Team sprint
2004: 1km time trial
2002: 1km time trial & team sprint
2006: Team sprint
2002: 1km time trial
"It has gone from a minority sport to a major sport and to have been part of the journey is a massive honour."
Asked for his career highlight, he said: "It's tough to pick one special moment - so I'm going to pick two.
"Athens - stepping onto the podium, hearing my name read out and then hearing 'Olympic champion' after it. To me that was what my career was all about.
"I thought nothing could compare to that but in London, to end my career with my sixth gold medal, in the nature of the keirin, was a really special moment. I've had so much fun."
Hoy is an ambassador for the Glasgow Commonwealth Games and is also part of the bid to bring the 2018 Youth Olympics to the city. He also hopes to launch his own brand of bikes.
He added: "I'm looking forward to spending time with [wife] Sarra and putting something else in my life ahead of cycling.
"People say cycling is a sacrifice - it's not a sacrifice, you choose to do it. But every decision in your life is based around the sport."
Hoy won his first Olympic gold medal with victory in the one kilometre time-trial at Athens in 2004, having previously won silver in the team sprint in Sydney.
Successes in the team sprint, keirin and sprint at the Beijing Games four years later gave him three more golds and he was voted the 2008 BBC Sports Personality of the Year before being knighted in the New Year's Honours list.
He added two more by winning the team sprint and keirin events at London 2012.
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