The British 200m breaststroke record holder, a former world short course champion, cut a glum figure at the Olympic Aquatic Centre earlier this month.
And he admitted he may struggle to find the motivation to continue with training, despite the prospect of a home Commonwealth Games in Glasgow in 2014.
But he insisted he would take some time to reflect on the trials, where he was beaten by close friends and training partners Andrew Willis and Michael Jamieson, before making a firm decision.
"I still love the sport but my body won’t take it anymore," said the 28-year old.
"I know that the time is right for me and I am confident it is the right decision. The Commonwealth Games in Glasgow are just a little bit too far away.
"I am happy to stop at a time when I still love swimming. I haven’t lost any passion for it and I certainly want to stay involved.
"My plan now is to get my level three coaching qualification as I really want to give something back to the sport I love.
"I’ve worked and swum with some fantastic people over the years and I’d like to thank all those who have supported me throughout my career."