Lewis Hamilton back with Pussycat Doll Nicole Scherzinger

In January, the 25-year-old British racing driver and the US pop star, 31, said they were splitting to concentrate on their careers.

However the pair, who vowed at the time to remain friends, are an item once again, after finding a happy compromise with their work life balance.

Hamilton said: "Things are good. She's working really hard on her album and on Dancing With The Stars and I can't wait to see how well she does with that and hopefully I can get over and support her."

He added: "She's supporting me with my racing so we're focusing on our careers and we're doing our best to stay in touch and keep strong."

However, Hamilton said there was "no truth" in rumours of marriage.

The McLaren driver, who begins this season's Formula 1 campaign at the weekend in Bahrain, confessed he was in the best physical shape of his career, and his ultra-fit training partner, Scherzinger, should receive some of the credit.

"We go to the gym together quite often and she goes running with me," he said. "She does her own programme and I do mine and it's pretty cool."

He added: "We try not to compete on many things because she can keep up with pretty much anything."

However, the biggest obstacle in Hamilton's fitness regime are the ravenous local dogs around Lake Geneva, where he goes jogging.

He said: "I had a dog jump up at me, it seemed to go for my trainers, I don't know what it is about them that they love... I think it must be the bright colours they like.

"I've been attacked - well not attacked exactly - but dogs barking and trying to run after me but I keep cool... I just give the dog a kick."

Hamilton was speaking at the launch of his new alternate reality game from Reebok, secretlewis.com.