The brothers' book, which will be published by Penguin, is billed as "the definitive Triathlon book, blending their life stories with insights into training, psychology and performance".

Viking editorial director Joel Rickett has bought world rights from Professional Sports Group and Swim, Bike, Run will be published as a hardback and ebook, at the start of the triathlon season.

The Brownlees won gold and bronze medals at the London 2012 Olympics, the first time two British brothers had won medals in an individual competition at an Olympics since 1900.

Last weekend Jonny (pictured top, right) became the International Triathlon Union (ITU) world champion in Auckland, New Zealand, taking over the title won by his brother last year.

"In a summer full of legends and inspiration, the Brownlee brothers stood out," Rickett said.

"Their winning race was simply breathtaking.

"Their story is all about shared lives, training and performance, pushing each other to fresh heights.

"They share a total dedication to the sport and a wonderfully down-to-earth, positive attitude."

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