Ash Barty joins Shane Gould, Mark Ella and select others in retiring at the peak of her powers

Ash Barty's retirement from professional tennis at the age of 25 was a shock to many, considering she was world number one and fresh off winning the Australian Open.

But as Barty revealed, she is leaving on her own terms and it is a decision that has been met by widespread respect and admiration. 

She is not the first athlete to call time at the peak of their career, nor at an age when it appeared they could dominate for years to come.

While this is not an exhaustive list, here are some other athletes who have exited their chosen sport earlier than expected.

Australian swimmer Shane Gould was only 15 when she won three Olympic gold medals — in addition to a silver and bronze — at the 1972 Munich Olympics.

Her victories in the 200 and 400 metres freestyle events, and the 200m individual medley, were all achieved in world-record times.

A second Olympics appearance at the 1976 Montreal Games seemed inevitable, but Gould quit swimming at the age of 16.

She told the ABC in 2012 she felt «trapped in being the image of 'Shane Gould, the swimmer'».

«People ask me why I quit swimming,» Gould said.

«I was being asked to do things that were really impossible for anyone to do. I was 16, untrained in the media, had no mentors of my age, no role models. The swimming part was fine; I could have kept doing that.

»I just couldn't do the other thing. So I think at a very fundamental level that's why I stopped."

At 25, Wallabies star Mark Ella had the world at his feet.

He was considered the best five-eighth in international rugby and had scored a try in each of the Wallabies' Tests as they completed a historic grand slam on their 1984 tour of Great Britain and Ireland.

But months later, Ella announced his retirement, bringing to an end a brief but