Hamilton 'more committed than ever'

The McLaren driver became Formula One's youngest ever champion last year and will start his title defence next month in Australia.

Hamilton admits having won the championship has not sunk in yet, but he claims he is working harder than ever in order to clinch another title.

"Winning the world championship in Brazil seems such a long time ago now - things move so fast in Formula One, even when you're not at the race track," Hamilton told the official Formula One website.

"To be honest, I don't really think of myself as world champion yet - I think that will finally sink in when I get to Melbourne for the first race - so I don't put any extra pressure on myself to live up to that.

"Obviously, becoming the champion does take some weight off your shoulders but I don't really look too closely at it: I'm just spending every moment focusing on 2009, improving my fitness, working with the team and testing the car. I'm more committed than ever."

The Briton, whose team boss Ron Dennis will be stepping down before the first race of the season, said he is not expecting any significant changes in the team despite Martin Whitmarsh taking over at the helm of the racing activities.

Hamilton expects the change, however, to be good for the team.

"I know Ron and Martin very well. And I'm sure that the change at the top of the team will only bring us benefits," said Hamilton.

"It will allow Ron to take a step back and concentrate on running the whole group, and it will also allow Martin to get fully involved in the Formula One team. But I don't think you'll see many big changes - there's not much that needs changing, after all.

"I know a lot of people will be watching Martin once we get to Australia, but he's a great bloke; really professional, a good laugh and totally committed. I know he'll do a fantastic job."