She is engaged to a Super Bowl winner, counts Coca-Cola and Hershey's among her personal sponsors and she is expected by many to ensure that there is no repeat in Beijing of the Great Britain one-two in the 400 metres at last year's World Championships in Japan. Sanya Richards watched in the stands in Osaka as Christine Ohuruogu and Nicola Sanders won gold and silver, a victim of the cut-throat nature of the United States trials. This year she is banking on being America's golden girl.

That she beat both Britons comfortably on the way to winning a half-share in the $1million (about £500,000) bonus for winning at all six Golden League meetings did little to defuse the pain - she was the world's No1 but not the world champion. In Beijing, it is time for revenge.

“My off-season workouts were extremely hard and I just kept thinking of Christine and Nicola and Novlene [Williams, the bronze medal-winner from Jamaica] and how they got the chance to run for the medals and I didn't,” Richards said. “This year is running the way I hoped 2007 would.”

It was a year of highs and lows for Richards. The large cheque for her Golden League dominance was the high, fourth place in the US trials was the low. She won a gold medal in Osaka as part of the US 4x400 metres relay team, having earlier, after much inner debate, sat in the stands to watch Ohuguoru's golden moment.

“I kept wavering on that and finally I decided to stay and watch the race,” Richards said. “I ran against these athletes all season and to see that race go off without me was very hard. I rode the team bus back to the hotel and I don't think I spoke too much.”

Some put down her failure in the US trials to travelling to Europe in search of the Golden League cash. Richards, though, puts it down to illness. “I was diagnosed with Behçet's disease last year,” she said. “It's a very rare disease and it took a long time to diagnose. The medicine I was initially taking was contributing to my fatigue. It wasn't the travel that got to me it was the rounds. And after two rounds I felt so flat for the finals.

“I used to have really bad flare-ups with mouth ulcers and skin lesions that were painful, and really bad fatigue. The problem was that it was showing up while I was competing, so I wasn't able to go to a doctor and do all the tests. They were giving me medication to calm it down, but it wasn't getting rid of it. Since December 31 I haven't had any flare-ups, every day I feel better in practice and my recovery is much better. But it could come back. There are precautions I take, I'm still on my medication, I've changed my diet and I have to avoid stress - which is hard at times.”

The year began well when Aaron Ross, her fiancé and a cornerback with the New York Giants, helped to win the Super Bowl. “Having won the Super Bowl, he's getting a lot of publicity and with myself going into Olympic year, it's kind of been the same,” Richards said.

Richards, 23, grew up in Jamaica and her family moved to Florida when she was 12. By that time, she had her track grounding. She rose to become the world's best after teaming up with Clyde Hart, the coach, two years ago. Hart guided Michael Johnson, the 200 metres and 400 metres runner, to Olympic glory in 1996 and 2000, as well as Jeremy Wariner to the men's 400 metres gold medal in Athens four years ago.

There were no alarms for Richards in the US trials this year and she has sharpened up her speed by running in the 200 metres at Golden League meetings in Rome and Paris. “Williams, Ohuruogu and Sanders are my biggest competition,” she said. “After medalling last year, they'll be confident and I think they'll run well through the rounds. To me, this year I'm the underdog and that's a good place to be.”