The 28-year-old successfully defended the Olympic coxless four title he won with Andy Triggs Hodge, Pete Reed and Steve Williams at Beijing 2008 at London 2012 last summer.
James joined forces with Triggs Hodge and Reed once again at London 2012 as well as Alex Gregory as the British four won their heat, semi-final and then the final to take gold.
That maintained Britain's record of winning the coxless four title at every Olympics since Greg and Jonny Searle and Rupert Obholzer and Tim Foster had to settle for bronze at Atlanta 1996.
It is unlikely that James will be in Rio in 2016 to defend his title a second time with the double Olympic champion planning a new career but one that will still involves the Games.
"I have done a couple of races with old mates and doing a bit of rowing with some of my alumni and enjoying that side of it," said James.
"I have been thinking over the last four years about what I wanted to do. I have got quite a few good ideas but now it is time to put that seriously into play.
"I would like to stay in the Olympics somehow whether that's in rowing or media or the organisation. I studied engineering at university and that's a clear route to look down as well.
"It's trying to find a balance for both and just because you're good at one thing doesn't mean you will be at another."