The 25-year-old from Los Angeles is recognised as a 200m specialist and is a two-time Olympic silver medallist in the event as well as a three-time world champion over the distance.

However, she was part of the US 4x400m relay that won gold at the Beijing 2008 Olympics and again at the 2009 World Championship in Berlin while she became the first-ever sprinter to win US titles in the women's 100, 200 and 400m at this year's USA Track and Field Championships to show her strength across the sprint distances.

"I'm looking forward to trying something new out there in Daegu," said Felix (pictured) during the first in the 12 for 12 media teleconference series hosted by the United States Olympic Committee (USOC).

"I'm kind of stepping outside my comfort zone with the 200m and 400m double.

"With the 400m first, that was real dilemma in deciding if I wanted to go for it or not.

"For me, it would have been much easier to decide if the 200m was first being that it is my primary event and I think it is easier to sprint first.

"I think the most difficult thing is trying to come off three rounds of 400m and then sprint again.

"But I think it will be a real learning curve and be really interesting.

"Hopefully it will go well but I think most of all, I'll learn a lot for the schedule and participating in it ahead of London 2012.

"After Daegu, my eyes are definitely set on London.

"I'm a lot more mature now than when I started and I'm heading into London with a lot more confidence and knowledge.

"I feel like I'm a lot stronger and I think that will really help me in London."

Felix is also set to run in both the 4x100m relay and 4x400m relay at the World Championships, which take place from August 27 to September 4, but admitted that she will only do so if she is not fatigued from her individual events so as to harm the team's medal chances.

"I'm in the pool for both the 4x100m and 4x400m relays and the plan is to compete in both but I'm going to communicate with the coaches the whole way through," she said.

"So if anything is feeling funny, I won't run in them as we want the best team out there.

"But if all went well, I would run in both relays."

Felix was joined on the USOC 12 for 12 media teleconference by American triathlete star Sarah Groff.

Contact the writer of this story at [email protected]