American actress Sydney Sweeney recently revealed the remarkable physical transformation she underwent to portray boxer Christy Martin in an upcoming biopic about the athlete’s life. In a candid conversation with W Magazine, Sydney shared that she gained over 30 pounds to authentically capture Martin’s powerful and toned physique.
At 27 years old, Sydney described the intense preparation involved: “When I joined the project, I had roughly three and a half months of intense training.” Her daily routine included an hour of weight training in the morning, two hours of kickboxing around midday, and another hour of weight training in the evening.
This demanding regimen dramatically reshaped Sydney’s body. “I couldn’t fit into any of my usual clothes. Normally, I wear size 23 jeans, but I was in size 27 during training. My chest grew, and my butt got a lot bigger—it was wild! I thought, ‘Wow, this is something else,’” she said.
Despite the challenges of this physical transformation, Sydney embraced the newfound strength it gave her. “It was incredible—I felt unbelievably strong,” she said enthusiastically.
Director David Michod commended Sydney’s commitment, noting that she “trained relentlessly for the role” and seemed most joyful when immersed in the boxing scenes, fully engaged in the physicality of the sport. Michod also marveled at how quickly Sydney returned to her usual physique—just seven weeks after wrapping filming.
Sydney’s lifelong love for sports and outdoor activities helped lay the foundation for this demanding role. Encouraged by her mother to pursue diverse interests beyond acting, Sydney developed skills in skiing, wakeboarding, and kickboxing. “I often had bruises all over, but I loved every minute of it! My mom always wanted to make sure acting wasn’t the only thing in my life,” she joked.
Sydney Sweeney’s dedication and passion highlight the extraordinary effort behind bringing Christy Martin’s inspiring story to the screen.