British marathon runner Mara Yamauchi has confirmed her retirement from the sport with immediate effect.

The 39-year-old has decided to call time on her career after she was forced to pull out of the London Olympics last summer with 10km of the race run because of a foot complaint.

"I have achieved my childhood dream of becoming an Olympian, and enjoyed many years training and competing as an elite athlete," she said.

"To be able to do what you love as your job is a rare and special privilege, and I am very grateful to all the people who have enabled me to do that.

"I have now decided that it's time to leave elite competition behind, and instead I will run for enjoyment and to stay healthy."

Yamauchi is the second-fastest female British marathon runner in history behind Paula Radcliffe.