Norfolk's Chrissie Wellington has retired.

The four-time World Ironman Champion has taken a year long sabbatical from a sport in which she remained undefeated.

In a statement on her website, the 35-year-old, from Feltwell, said: 'Over the past 12 months I have had time to reflect and think, about my past and, of course, also of my future. Being a professional Ironman athlete has been one of the greatest experiences of my life. I have achieved more than I could have ever imagined, and been so fortunate to travel to some beautiful places, compete against the best in the world, and forge many lasting friendships. Those life-changing experiences and memories will stay with me forever.

'As an athlete I sought 'the perfect race'. That race within myself where I dug to the depths mentally and physically, and that hard-fought race with my competitors. The World Ironman Championships in 2011 was the icing on the cake for me as an athlete. It was my 'perfect race' and it 'completed' me.

'My passion for the sport hasn't waned, but my passion for new experiences and new challenges is what is now burning the most brightly. Hence, I have got to the point where I know that it is right for me to retire from professional Ironman distance racing.

'Needless to say this decision has not come easy, but deep in my heart I know it is the right thing for me to do. My future will, of course, involve sport and triathlon – but it will no longer be the axis around which my entire life revolves.

'In the past year, since I won the World Ironman Championships, I've thoroughly enjoyed being able to dedicate myself to other aspects of my life, including charity work, public speaking, policy development, and of course publishing and promoting my autobiography, 'A Life Without Limits'. I will keep everyone updated on my future plans via my website -www.chrissiewellington.org and twitter – @chrissiesmiles.

'Of course I could not have achieved what I have without the unwavering support of so many people – my family and friends, my manager Ben and the Wasserman team, my wonderful sponsors who have enabled me to make my passion my career, my coaches who have brought out the best in me, the race organisers, my fellow pro athletes, the media who have given me such an amazing platform, the volunteers and all the thousands of age groupers around the world.

'I will continue to act as an ambassador for a number of my sponsors. Their support for me has been incredible.

'Finally, I would like to take this opportunity to thank every single person that has been part of my Ironman journey, and wish you all the very best for the 2013 season and beyond.'