U.S. sprinter Allyson Felix should be mentally and physically ready to face some of the fastest women on the planet when she goes for 200 and 400 meters gold at the World Championships but it is how she handles the moments away from track that could determine her success.

The three-times world 200 champion is bidding to become the first woman to win a world championship 200-400 double and coach Bob Kersee told Reuters that the key was balancing her training with the myriad of obligations that come with being a top athlete.

How to handle each and every day, that is the key, Kersee, who has coached Olympic champions and world record holders during his long career, said in a telephone interview.

Training, rest, media meetings and sponsorship appearances must be carefully managed at the August 27-September 24 championships in Daegu, South Korea, he added.

Felix's heartbreaking loss to Jamaican Veronica Campbell-Brown in the 2008 Beijing Olympics 200 final showed what can happen when the balance is not right.

There is no doubt in my mind .... nothing against Campbell, she (Felix) would have given Campbell a better run for her money if we had eliminated some of off-the-field, off-the-track activities and monitored her time and rest, Kersee said.

That taxed her more than anything else.

SMOOTH RIDE

While Felix has beaten her Jamaican rival three times in the World Championships 200, Beijing marked Campbell-Brown's second successive Olympic triumph over the American at the distance.

The Beijing loss was particularly hard to take and Felix is determined to change things in 2012.

I have broken those (Beijing) races apart, I think I have pretty much figured out going into London what I need to do to be successful, said Felix, the most high-profile U.S. athlete in Daegu. It is all about learning to say no to different things.

I wasn't at my best in Beijing and it was due to things that I could have changed.

Kersee promised to make it a smoother ride for Felix this time. The traveling back and forth .. the sponsor appearances ... being in a zone she has never been before. All those things are going to weigh on her mind, he said.

Even the extra five minutes Felix would want to spend talking to reporters, something the Californian thoroughly enjoys, could be curtailed, added Kersee.

Whatever happened in a preliminary race or a final, Felix would not have much time to reflect or enjoy it due to the tight schedule.

You focus at what is ahead of you, Kersee said. She knows that and has bought into that, and I think she can handle it.