Ronda Rousey Opens Up About Her Introduction to MMA Fighting in New Documentary

MMA legend Ronda Rousey is opening up about her inherited interest in fighting – and how her start in Judo eventually led to her international fame and success as a UFC fighter.

In The Hurt Business, a MMA documentary out Thursday featuring fighters Jon "Bones" Jones and Rashad "Suga" Evans, Rousey explains that her mother was responsible for her initial enthusiasm for martial arts.

In a first look at Rousey's interview in the film – released exclusively to PEOPLE – the athlete says she was drawn to MMA fighting after watching Gina Carano take on Julie Kedzie in 2007, but initially tried to stay away from the sport.

"My mom says all the time you can't un-have a thought. I tried to push it out of my mind, but I watched them fight and watched how much respect and interest it got from everyone, and I was envious in a way," she admits. "I knew that I could beat those girls, but no one in the room had any reason to believe me."

"I started being frustrated by the fact that I knew I was the best woman fighter in the world and no one believed me."

The film's director, Vlad Yudin, says he was blown away by Rousey's confidence and passion during filming.

"I think she's definitely somebody who is focused on her career and focused on being successful inside the octagon and outside the octagon," he tells PEOPLE. "She seems very passionate about what she's doing."

Yudin says he also asked Rousey about her thoughts on the controversial nature of MMA – and whether it promotes violence in society.

"I said 'Do you think MMA should be allowed in a modern society, is it acceptable?' And she said 'Absolutely yes,' " divulges Yudin. "Because we live in a society that is plastic and everybody is trying to be too conformed to something, MMA gives you ability to express yourself without being damaging."

"But in reality, if you think about it, it makes sense to those people who practice MMA and who do martial arts in general."

The Hurt Business will premiere in theaters nationwide for one night only on Thursday.