LONDON - David Beckham is convinced he's fit enough to embark on a year-round, continent-hopping football marathon.

He's doing it to try and get AC Milan into the Champions League, Los Angeles Galaxy to the MLS playoffs and, more importantly, play for England at the World Cup.

Faced by a tug-of-war between Milan and the Galaxy, the former England captain agreed a deal Sunday with both clubs to extend his loan contract at the Serie A club from Monday's deadline until June 30.

Beckham, who turns 34 in May, is renowned for his stamina. He said his three-month spell at Milan has made him even fitter, which will come in handy as he endeavors to play most of the year.

"I feel that physically I'm in possible the best shape of my career," Beckham told The Associated Press-affiliated SNTV. "I know that when I'm physically in the right condition it doesn't matter what age I am. I know that if I'm physically fit enough then I can play at the highest level."

Beckham will return to the Galaxy for the second half of the MLS season, and the likelihood is that he will return to Milan in late November, either on another loan deal or in a permanent move.

"People have talked about the amount of games that I will be playing and the amount of hours I will be playing football. But it's never bothered me, that side of the game," he said. "I have always loved playing as many games as possible. I get a good four weeks rest in the summer and then I get another rest in December and it sets me up right to then go into January fully fit and fully ready and at my best."

Although Beckham wanted Milan to buy him, he said he was happy with the current arrangement which was agreed "with a lot of hard work, a lot of to-ing and fro-ing."

"I thought it would go down the last hour," he said. "I would be packing my bags and the decision would be made. But it's the day before, which has been good. I've played for so many great clubs and I've been able to help myself stay in Milan, if I can put it that way. That's the big thing for me."

Beckham said the biggest reasons to stay with the seven-time European champion were to help Milan qualify for next season's Champions League and to try and play in his fourth World Cup for England.

"AC Milan belong in the Champions League," Beckham said. "It's not just about the money that the teams get from qualifying, it's about the whole legacy of big clubs. And, hopefully, I can be part of that and part of taking us into the (later) stages next year."

Beckham, who previously played for Manchester United and Real Madrid, also wants to help the Galaxy at least reach the MLS playoffs after two failures in a row.

"Obviously, on the pitch I want to be more successful than we have been in the last two years," he said. "A club like the Galaxy can't afford to not be in the playoffs. We've got a good manager, Bruce Arena, we've got some good players. It's important this season that we reach the playoffs."