Allyson Felix fit for Rio Games

Four-time Olympic champion Allyson Felix says she has regained full fitness as she steps up her Rio Games 2016 preparations after an extended injury layoff.

The 28-year-old US sprinter told rio2016.com that she endured a difficult recovery after tearing a hamstring during last year's world championships, reports Xinhua.

But having run the fastest 200 metre time of the year in September in Brussels, Felix declared she is back to peak condition.

"This year has been really different for me," Felix said.

"It has taken a lot of patience and I've had to focus on each stage of my recovery at a time, without rushing anything. So it's good to be 100 percent fit now and ready to start 2015 full of energy."

Felix equalled Usain Bolt as the most successful athlete at London 2012 with a hat-trick of gold medals in the 200m, 4x100m relay and 4x400m relay.

She admitted to feeling honoured to be mentioned alongside Bolt.

"(He) is the greatest athlete of all time, so the comparison just makes me happy," she said.

"It's good to know that people think you have something in common with an athlete who has achieved so many special triumphs in his career."

Felix was in Rio for the first time as a guest of the US consulate.

She said the trip had left her eager to be a part of the first Olympic Games in South America.

"The Rio Games will be special," she said. "It's good to visit before the Games, to feel the city's energy and experience the incredible atmosphere here.

"It would be great to win another gold medal here, but it's too soon to know what might happen. I'm guided by my objectives and will always try to push my limits."