Liam Neeson has revealed the secret behind his ability to play demanding action roles – giving up caffeine.

The 62-year-old, who returns to the big screen tomorrow (Fri) as former CIA agent Bryan Mills in "Taken 3," said he the old aches and pains he used to suffer from disappeared when he quit the Irish habit of drinking cups of tea throughout the day seven years ago.

The New York-based actor, from Ballymena, Co. Antrim, said: "I've been drinking caffeine for years and years, but I stopped about seven years ago.

"I got this masseuse who does all these Broadway dancers and he was working the lactic acid crystals between my muscles very, very painfully. I was in agony and he said afterwards, 'Do you drink a lot of caffeine?' And I said, 'I've been drinking caffeine since I was two'. Being Irish, you're always drinking cups of tea.

"He said, 'You should think about cutting it out.' And I did and the cramps and stuff disappeared by, like, 90 percent."

The Hollywood A-lister – who now drinks decaffeinated tea – also revealed that regular exercise and work-outs have enabled him to star in high-octane blockbusters, including recent pictures like 'Non-Stop' and 'A Walk Among The Tombstones.'

However, in an interview with the BBC, he admitted that his long-term stunt partner performs the more challenging scenes in his action pictures, including "Taken 3."

He said: "I've always kept fit. I've my own gym and I've a hitting bag as well.

"I've a great stunt double who's worked on 16 films with me. I do my own fighting, but he does all the heavy stuff. I love the fighting – it's like being a kid in a toy shop. I might get the odd little scrape or cut, but that's it."

The father-of-two also told how the 2009 death of his actress wife Natasha Richardson in a skiing accident has helped him appreciate the importance of family.

He explained: "It was a horrible tragedy. My mother-in-law and sister-in-law just moved in with me like a pincer movement. My family in Ireland of course were there too. I'll always be indebted to them."

He added: "It really, really made me realize the power of family and how sacrosanct it is and should be and how important it is. It's the basic unit of society and that was certainly reinforced with me after Natasha's passing."