Jennifer Lopez Channeled Her Understanding of ‘Complicated’ and ‘Dysfunctional’ Love into Unstoppable Role (Exclusive)

Jennifer Lopez is opening up about how she understood the “complicated dynamics” at play in her new movie Unstoppable.

Lopez, 55, plays the real-life Judy Robles in the biopic opposite Jharrel Jerome as Anthony Robles, who was born with one leg and became a wrestler who went on to win an NCAA national championship. Portraying Judy’s “dysfunctional and unhealthy” relationship with her husband and Anthony’s stepfather Rich, played by Bobby Cannavale, ultimately felt “very cathartic,” the actress-musician tells PEOPLE. 

“Women who are moms who get in relationships, and you struggle with them, and you find yourself in dynamics that are not healthy, but you care about the person, love the person,” Lopez, who is mom to twins Max and Emme, tells PEOPLE at the Toronto International Film Festival on Saturday, Sept. 7. “That's those complicated dynamics about life that I understand really well.”

And “everybody can relate to” such a story — “a lot of women and men, by the way,” the Unstoppable actress and producer adds of the film, which was mostly shot early in 2023 prior to the SAG-AFTRA strike and resumed that December. “I think all of us do. I don't think there's anybody who is exempt from experiencing those types of things at times.”

Unstoppable, adapted from Anthony and Austin Murphy’s book of the same name, counts Ben Affleck and Matt Damon among its producers, with William Goldenberg making his directorial debut. Anthony, who along with his mother attended the Sept. 6 Toronto premiere with the cast and filmmakers, is also a producer (and Jerome's stunt double) on the film.

“When Judy and I first spoke, it was just about, for me, learning as much as I could about how she really felt and all of these things and what really happened,” recalls Lopez. 

Earlier in Judy and Rich’s relationship, as portrayed by the screenplay from Eric Champnella, Alex Harris and John Hindman, “there was an earnest time,” she continues. “He thought he was helping raise this kid [Anthony] when he took him on. There was something between him and Judy that was real, as complicated and maybe as dysfunctional and unhealthy as it was.”

Judy Robles “was very open with me” discussing her family dynamics, Lopez adds, “and I was open with her about my own struggles.”

The frank discussions allowed Lopez “to find commonality” in their life experiences, she says, “because at the end of the day, you bring a lot of yourself to these characters. You have to understand something about them that you love and that you understand and that you empathize with … It was a real honor for me to do it and very cathartic for me as well.”

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories. 

But sometimes, she says, depicting Judy's story could be difficult. “I struggled on the set a couple of times,” recalls Lopez. “I was like, ‘Ugh, too close.’” The experience also "got me to a different place in my life," she says, noting that acting “teaches you about yourself and you learn things, and it was really a necessary and beautiful experience.”

Unstoppable, from Amazon MGM Studios, will be in limited theaters this December and streaming on Prime Video. It costars Michael Peña and Don Cheadle.

The Toronto International Film Festival runs through Sept. 15.