Joe Calzaghe celebrated his 36th birthday last Sunday with three training sessions, as he prepares to face Bernard Hopkins in Las Vegas on April 19 - his first bout at lightheavyweight and his first in the United States. Challenges are needed, but Calzaghe insists that 2008 will be his last year as a boxer; he wants to enjoy his 37th birthday.

“I don't really feel that I want to keep fighting,” Calzaghe, who has been a world champion for 10 years, said. “When I'm out of the gym, I don't really miss it. What I've achieved in my career is amazing and I'd love to retire unbeaten like Rocky Marciano. There is a fine line between retiring too early and going on too long, and only hindsight can tell you if you made the right decision.

“I'm physically fit enough to fight on beyond 40 - my best performances have been in my last five fights. But mentally it's different and it's harder to motivate myself, which is why I need these kinds of challenges now.”

Last year's challenge was to unify the WBC, WBA and WBO super-middleweight titles, which he did by beating Mikkel Kessler at the Millennium Stadium, Cardiff, in November. If he gets past Hopkins, the biggest bout available would be against Kelly Pavlik, the exciting world middleweight champion, although Pavlik first faces Gary Lockett, Calzaghe's training partner, in Atlantic City on June 7. “Don't put it past Gary upsetting my plans,” Calzaghe said. “Gary is a big puncher and Pavlik has been dropped, so it can't be a mismatch.”

Junior Witter's next defence of his WBC light-welterweight title against Timothy Bradley, an unbeaten American, on May 10 at Nottingham Arena, will be shown live on ITV1. “The great British public will now be able to see the fighter who Ricky Hatton is avoiding,” Witter said. “I'm defending my WBC title, the most prestigious belt in boxing, a title Hatton has never been able to win; he got knocked out fighting for the WBC title in his last fight.”

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