From Starlet to Southpaw: Sydney Sweeney’s Knockout Transformation

By Kyra Greene

Sydney Sweeney is stepping out of the spotlight and into the ring for Christy, the raw, emotionally charged biopic chronicling the life and legacy of women’s boxing trailblazer Christy Martin. Premiering at the 2025 Toronto International Film Festival, the film is already generating serious awards chatter — and for good reason.

Directed by David Michôd (The King), and co-written with Mirrah Foulkes (Judy & Punch), Christy tells a story far larger than a career inside the ropes. Once hailed as “The Coal Miner’s Daughter,” Martin shattered ceilings in the male-dominated world of boxing — her 1996 undercard fight on a Mike Tyson bill put women’s boxing in the mainstream spotlight. She ended her career with a staggering 49-7-3 record, including 31 knockouts.

But Christy doesn’t just document the title belts and triumphs. It delves into the depths of Martin’s personal life, including surviving a near-fatal stabbing and shooting by her then-husband and trainer, Jim Martin — a man who would be sentenced to 25 years behind bars. From addiction struggles to hidden identity battles, from ESPN fame to life-altering trauma, the film explores what it means to fight — and survive — both in and out of the ring.

Sweeney, who also co-produced the project through her company Fifty-Fifty Films, underwent a physical transformation for the role. Speaking with W Magazine, she reflected on the intensity of the training:

“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,” she laughed. “But it was amazing: I was so strong, like crazy strong.”

Her body changed — but so did her perspective. The role required more than just physical endurance; it demanded emotional vulnerability and psychological depth. With Christy Martin herself involved as a consultant, the story is told with unflinching honesty and hard-won wisdom.

In an age of glossy sports biopics, Christy strips away the polish, revealing the pain, pride, and power behind one woman’s fight for survival and legacy. It’s as much about reclaiming identity as it is about resilience — a film that hits just as hard emotionally as it does in the ring.

Christy premieres September 2025 at TIFF. A wider theatrical release date is expected to follow.