The 28-year-old actress gained more than 15 kg and trained relentlessly for the role.
The biopic “Christy” premiered at the Toronto International Film Festival in September 2025 and is scheduled for release this week. The film tells the life of Martin, a pioneering female boxing icon in the 1990s and the first woman to be featured on the cover of Sports Illustrated.
In an interview with Sportscasting, Sweeney revealed she fell in love with the sport so much that she considered stepping into the ring.
“There was a moment in the middle of filming where I was like, ‘Should I give it all up and fight because I love this?'” Sweeney said. “Christy [Martin] said sign me up so this isn’t as hypothetical as you actually think it is. Yeah, I’d totally do a charity bout, that’d be so sick.”
Sydney Sweeney at the BFI London Film Festival in October 2025. Photo by Instagram/@sydney_sweeney
When asked about a potential opponent, Sweeney added: “It’s a surprise, you’ll have to wait, I’m serious. You’ve got to stay tuned for the pay-per-view and you’ll see it.”
To transform into Christy Martin, Sweeney underwent a rigorous training process, combining weights, a special diet, and gaining more than 13 kg.
“For about two-and-a-half months, I would weight train in the morning for an hour, box three hours in the middle of the day and then another hour of weight training at night,” she said on “Good Morning America”. “I started losing weight once I upped my boxing time and had to find that balance. I was just continually pounding more and more protein shakes.
“I loved it. I worked hardest on that left hook and I think what would get me through a fight is that I can take a punch. I wouldn’t quit.”
While the role was highly anticipated and generated Oscar buzz, the film has received mixed reactions from critics.
Both BBC and The Guardian gave the film two-star reviews. The latter called it “cliched”, stating that while Sweeney is “a convincing force to be reckoned with inside of the ring, she can’t get us to believe in all that much outside of it, an actor still trying too visibly hard to make it all seem effortless.”
Despite the reviews, Sweeney’s physical transformation has been praised. The actress emphasized she has no regrets for her dedication to the role.
Sweeney rose to fame with her 2022 Emmy-nominated roles in “Euphoria” and “The White Lotus”. Her recent credits include the 2023 box office hit “Anyone But You” and 2024’s “Madame Web”.