Sydney Sweeney gained 30lbs to play fighter Cristy Martin

"My boobs got bigger. And my butt got huge...I was so strong, like crazy strong."
Text: Alex Hopley
Published 2025-06-10

Sydney Sweeney certainly seems to be one of the busiest people in Hollywood right now. From films to TV to soap commercials, she's all over the place. But, she still makes time to put extra effort into her roles, such as training heavily for her performance in an upcoming Cristy Martin biopic.

Speaking to W Magazine, Sweeney elaborated on the rigorous training process she put herself through, gaining more than 30 pounds. "I loved it," she said. "I came onboard to play Christy, and I had about three and a half months of training. I started eating. I weight-trained in the morning for an hour, kickboxed midday for about two hours, and then weight-trained again at night for an hour."

"My body was completely different," she continued. "I didn't fit in any of my clothes. I'm usually a size 23 in jeans, and I was wearing a size 27. My boobs got bigger. And my butt got huge. It was crazy! I was like, Oh my god. But it was amazing: I was so strong, like crazy strong."

Sweeney then almost immediately lost the weight in order to slim down for her return to HBO's Euphoria. A bit of a Christian Bale-like body transformation for this performance, then. One that won over the director of the film, David Michôd, who said: "Our film is a wild mix of inspiring underdog sports-world story and personal saga. Sydney trained her butt off to play the part. The beauty of Sydney is that she turned up to work every day with her tail wagging, ready to go. No matter how tough it was, she was like a ray of sunshine."

The untitled Christy Martin biopic will release later this year.

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