(Cover) - EN Showbiz - Lynn Collins feared she wouldn't be able to "control [her] fierceness" on the set of John Carter.

The actress stars as Dejah Thoris in the Andrew Stanton-directed science-fiction film. Lynn says despite her martial arts background, she was still nervous about the amount of action sequences in the film.

"For me, the most challenging aspects of shooting the stunts and the fights was my adrenaline would get incredibly high," she told Cover Media. "And I feared that I wouldn't be able to control my fierceness.

"Then we would have to do more relaxed scenes and it was really hard to go from this high energy adrenaline rush to something where you'd have to relax. It was so much fun, and I was conquering fears constantly."

John Carter also stars Taylor Kitsch in the title role, and both Taylor and Lynn's characters are embroiled in action-packed stunt sequences throughout. Lynn says she had to put her fear of heights aside when it came to the extremely physical scenes under Andrew's direction.

"I'm sure if we do a [second film] I'm sure I'll be thrown around again," she laughed.

"The first stunt I saw, the stunt doubles were way up in the corner of the studio, and they dropped, and it was amazing, and I was like Wow, that was great.' And I started walking away, and they were like No, that's your harness', and I saw Taylor getting into his harness, and he looked at me and said No regrets Collins.'

"And from that moment, my fear was completely overcome by this challenge from this man. So I guess I should thank Taylor."

John Carter is released in UK cinemas on March 9 2012. (C) Cover Media