Christian Bale has joked that his wife prefers his alter-egos to him.

The 45-year-old star is renowned for his method acting and fully immersing himself in his roles, and although he doesn't do it as much anymore, he quipped that his spouse Sibi Blazic prefers when he stays in character.

He told PEOPLE: ''I do it less now that I have kids because I don't want to confuse them. My wife definitely had favourites. She was like, 'Ah, I miss him. He's gone. You're a d**k. I want you to be that character again.'

''[Sibi] actually really liked Trevor Reznik, from 'The Machinist'. I think it's just about him and me just f**king sitting there being too weak to be able to do anything. Totally incapable. Whatever she told me to do, I did it. I suspect it's that.''

Christian lost 60lbs to play the troubled insomniac in the 2004 movie and said he was the most relaxed he has ever been during the process of preparation and filming.

He explained: ''He was actually incredibly peaceful, incredibly Zen, no roller coaster. I slept two hours a night. That was it. I couldn't sleep longer than that. And [when] I was up, I would sit and read a book for eight hours straight, beginning to end, and I didn't have to shift.

''That was incredibly Zen. It was the most relaxed and calm I've ever been, and I think she just adored that. But also I know her, she would get really bored.''

However, Christian admitted that his method acting can sometimes cause problems when he tries to move on to a new movie.

He explained: ''Every single role I do, the next role I'm doing, it takes me forever to figure out how to play it not like the role I was doing last.''

''Like when I was coming to Ken Miles [for 'Ford v Ferrari'/'Le Mans '66:'], I kept on reading it like Dick Cheney [from 'Vice'] and I was going, 'this isn't going to work, come on mate, what's going on here?'''