The Hollywood actor - who is currently shooting 'Live Free or Die Hard' - wants to look perfect when he bares-all on the big screen.
Bruce said: 'I have a few naked scenes so I want to look good. But I am not going to be a size zero.' The ageing actor - who is set to return as police officer John McLean - has embarked on a gruelling training regime to turn his middle-aged spread into a buff body.
However, Bruce's expanding waistline hasn't hindered his sexual prowess.
At his 50th birthday party last year, he claimed his sex life was better than any 25-year-old's.
He said: 'Sex is much better at 50. You are in less of a hurry and know a few more tricks.' The handsome actor - who has been linked to a string of young beauties since divorcing actress Demi Moore in 2000 - claims he is still a great catch and insists his equipment is in good working order.
He said: 'I've got a great sense of humour and it's still all working, working well.'