Arnold Schwarzenegger admits he finds it hard to stay in shape now he is in his 60s.

The 65-year-old actor returns to the big screen for the first time in eight years in action blockbuster 'The Expendables 2', and although he is still in incredible physical condition he is willing to acknowledge his body doesn't quite React in the way it used in his younger years.

The former Mr. Olympia body-building champion said: ''It is tougher as you get older. Your metabolism slows down. Your muscles don't respond in exactly the same way anymore. When you do action scenes and fight scenes and run around you take longer to recuperate, but so what? It doesn't matter. It's not like we don't get paid for it.''

However, Schwarzenegger insists he hasn't changed his fitness and strengthening regime at all, despite his advancing years, and he can still lift mammoth weights.

Speaking at a press conference in London to promote 'The Expendables 2', he told BANG Showbiz: ''I do the same exercises I did 50 years ago and they still work. I eat the same food I ate 50 years ago and it still works.''

Referring to the only slight difference in his regime, he joked: ''I do the curls first now and the squats last.''

Schwarzenegger stars in the movie with Sylvester Stallone, Jason Statham, Dolph Lundgren and Randy Couture - who all reprise their roles from the first film - while Jean-Claude Van Damme, Scott Adkins and Chuck Norris are also part of the impressive cast.