Athletics: Eaton rules out doubling up at 2015 worlds

It is a step too far, even for the man dubbed the world's greatest athlete.

Ashton Eaton confirmed Friday that he would not compete in the decathlon and 400m hurdles at next year's world championships in Beijing.

The 26-year-old American is the Olympic and world decathlon champion, and has also snared the world record in the gruelling 10-discipline event, becoming the only athlete to score over 9,000 points.

In March, he also bagged his second world indoor heptathlon gold in Sopot, missing out on bettering his own world record by one second in the final, strength-sapping 1,000m.

But this season, he has walked away from what he does best for an outdoor season spent racing the 400m hurdles.

"It will be too difficult to compete in both the 400m hurdles and decathlon at next year's World Championships," Eaton acknowledged ahead of Saturday's Diamond League meet at the Stade de France in Paris.

"I have not done any decathlon training since my outdoor campaign started at the beginning of June."

Eaton, dubbed the world's greatest athlete by no less a figure than Jamaican sprint king Usain Bolt after his victory in London two years ago, said there was a different rhythm to competing in a single event as opposed to the decathlon.

"I am used to training for a competition, giving 100 percent and going back into weeks of training to prepare for the next one," he said.

"It's very different travelling from one meet to the next with a short space of time between competitions."

Eaton, married to Canadian pentathlete Brianne Thiesen Eaton, became the first decathlete to win an event in the Diamond League when he claimed victory in the 400m hurdles at Oslo's Bislett Games last month.

It promises to be a slightly tougher outing come Saturday, with the likes of Puerto Rico's Olympic bronze medallist Javier Culson, winner in Lausanne on Thursday, and the Dominican Republic's Felix Sanchez, a two-time Olympic champion, in the running.

"I was quite tired from the flight across (to Switzerland), which meant I felt good for the first half of the race," Culson said after victory in Lausanne.

"I began to fatigue in the second half and my last few hurdles were not as good as I wanted.

"But I felt smooth out there and I am looking forward to Paris."

Also in the field will be American duo Michael Tinsley and Jonny Dutch, two sub-48sec runners but yet to hit that kind of form this season.