Sydney Sweeney transformed for her role as Christy Martin in the upcoming film about the professional boxer -- and not just physically, but also her training regimen, diet and even her grandmother's shed.
The actress, 28, told "Good Morning America" on Tuesday that she actually "grew up kickboxing and grappling," but what drew her to the role was Martin's story.
"[She] was a professional boxer who came up during a time when women in the sport was unpopular. She was a trailblazer for women boxers," Sweeney said. "She ended up marrying her trainer -- much older -- who unfortunately manipulates her, and she becomes a victim of domestic violence. And when she tries to leave him for the love of her life, who was a woman, he stops her."
Sweeney continued, "I remember when I got on the first Zoom with the director, I said, 'I don't care, I want to produce this, I just want to be a part of telling her story and hopefully opening doors for other people. It is unbelievable.'"
Sweeney told "GMA" she gained 35 pounds for the role through her workouts and "protein shake after protein shake."
"It was so much fun though, because I grew up in Idaho with my family, and my grandma's my neighbor, and I turned her shed into my 'Rocky' gym," Sweeney said. "I put flooring in and boxing bags, and I brought my trainers up there and had a boxing coach and a weight trainer. And every single day I would weight train in the morning and then box for like two or three hours per day."
She also had the real-life Martin on set, which Sweeney said was "a dream come true."
"It was so fun having her there, especially during the fighting scenes. I could hear her at the bottom of the ring going, 'Hit her with a left hook!' Like, 'You know what I'm going to do, Christy,'" Sweeney said with a laugh.
The actress, known for her breakout role on the HBO series "Euphoria," also hinted Tuesday at what to expect in the series' upcoming season, now that she has officially wrapped.
"The only thing I can say is it's about God," she said. "Some people are going to find God, some are going to need God."
With the holidays around the corner, Sweeney revealed her early Thanksgiving plans with friends, saying she is hosting a "Shrek"-themed Friendsgiving party.
"Everybody has to dress up as different 'Shrek' fairy tale character," she said of the upcoming Key West celebration.
"Christy" hits theaters Friday Nov. 6.
