Winckless went on to win world championships in 2005 and 2006 as part of the quadruple sculls crew that also featured fellow Olympic medallist Katherine Grainger.
But despite overcoming a knee injury that kept her out of the 2007 season and helping GB to fifth place in the eights final at the Beijing Olympics, she has resisted the continuing until London 2012.
She added: "Staying on for the London Games would have been a big attraction, but I hope to be able to stay in the sport and contribute in other ways."
Marketing consultant Winckless, who has worked part-time throughout her rowing career, was an athletes' representative and part of the committee that designed the 2008 Olympic kit to make it more user-friendly.
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