Gwyneth Paltrow gets tips from Robert Downey Jr for new film

The actress may have gained 20 pounds and practiced guitar until her fingers bled for her role in the upcoming flick but it was Robert who prepared her for it.

Paltrow turned to Downey, 45, for tips to help her play an alcoholic country star in the film.

She told US entertainment show Extra: 'There is a certain aspect of the addiction that went so far, I could only imagine it up to a certain point, but I couldn't imagine it as bad as she had it.

'He [Robert Downey] was amazing. He was very generous and kind of helped me understand addiction and how it works and from that point on I really felt like, okay I get it now.'

The 38-year-old also had to learn to play guitar for the film role.

She added: 'It's much harder than it looks when you've never done it because first your fingertips, like mine, were bleeding and cracking.

'It was definitely a challenge, but it was great, 'cause now I can sing for my kids.'

Country Strong hits cinemas in the US on January 7.