Jake Gyllenhaal's Boxing 'wake Up'

Jake Gyllenhaal ''wakes up'' when he's hit in the face.

The 'Southpaw' actor - who stars as a boxer in his latest movie - has admitted he didn't mind being punched for his role.

He said: ''I got hit pretty hard in the face. All the producers ran [over]. I don't think out of real worry for me, but just the fact that we were only two weeks into shooting.

''There is something jarring about being hit in the face. I don't know how to explain it. It wakes me up.''

Whilst the 34-year-old star understands it would be ''initial instinct'' to move away, he learnt moving towards his aggressor was the right course of action.

He explained: ''Your initial instinct is to lean out. It's the instinct to lean in that took me five months.

''Hitting someone - I don't have as much of a problem with that.''

Meanwhile, Jake's co-star Rachel McAdams - who watched the Hollywood star get ''pummelled'' during filming - has admitted she was ''very worried'' about him.

She told Details magazine: ''They were always playing hardball - there was never any letting up.

''I was very worried for him, but I knew he had it under control.''