Sydney Sweeney Transforms for Gritty Christy Martin Biopic, Gaining 30 Pounds for Boxing Role

Sydney Sweeney is stepping into the ring for her most athletic role to date, portraying boxing legend Christy Martin in an upcoming 2025 biopic. While headlines have recently focused on Sweeney’s controversial soap promo, the actress has been deeply immersed in transforming herself physically and mentally for this demanding part. From early 2024 through November, she dedicated herself to intense training to authentically capture the grit and strength of Martin, a trailblazer in women’s boxing.

Training Transformed Sweeney Physically and Mentally for Her Most Demanding Role Yet

Sweeney described her rigorous training routine, which spanned three and a half months and included daily weight training sessions and hours of kickboxing. The shift not only altered her physical appearance—she gained around 30 pounds—but also changed how she felt about her body. Known for more petite roles in The White Lotus and Immaculate, she embraced her new size, expressing pride in her newfound strength and size changes, such as a fuller figure and increased muscle mass.

While the film still lacks an official title and trailer, the first promotional images hint at Sweeney’s dramatic transformation, showcasing her muscular frame. The film will chronicle Christy Martin’s journey from a small-town fighter to a boxing icon and the first woman inducted into the Boxing Hall of Fame. Sweeney’s physical dedication is expected to add authenticity to this gritty underdog story, which combines both career triumph and personal struggle.

A Shining Force On Set, Seamlessly Balancing Grit, Glamour, and Career Versatility

Director David Michôd commended Sweeney’s unwavering commitment and positive attitude during filming. He highlighted Martin’s complex life story—marked by success, domestic violence, and survival—as a compelling narrative. Sweeney not only endured intense physical demands but also maintained a bright and dedicated presence on set, showing up each day enthusiastic and focused despite the challenges.

Following the wrap of the boxing film, Sweeney swiftly transformed back into a more glamorous image for her role in Euphoria Season 3, impressing even her director with her dramatic change in appearance. She continues to remain a high-profile figure in entertainment, with Echo Valley debuting on Apple TV+ on June 13 and The Housemaid set for release on Christmas Day. With a packed schedule and transformative roles, Sydney Sweeney is proving her versatility and commitment as an actress.