Sydney Sweeney is taking on a different kind of role, as she’s playing a trailblazing boxer in the upcoming Christy Martin biopic, proving she’s more than ready to throw down. For the sports flick, the Madame Web star underwent a massive physical transformation for the role, gaining 30 pounds of muscle and diving headfirst into the grueling demands of portraying one of the most iconic fighters of the ’90s. Now, her co-star, Katy O’Brian, is explaining how it felt getting “punched quite a few times” by Sweeney.
During a red carpet interview shared at the Eddington premiere via an X post by Variety, Katy O’Brian opened up about her and Sydney Sweeney’s intense fight scenes on set. O’Brian shared a fun take on taking jabs from her on-screen sparring partner:
[I] got punched quite a few times, yeah…. It felt good. Yeah, I loved it. It was great. It better read well on camera.
The Mandalorian actress, a powerhouse in her own right who plays one of Martin’s opponents in the film, didn’t seem to mind getting hit a few times. However, that begs the question of what it was like for her to hit Sweeney, who signed up to get ripped for her role. O’Brian admitted that she wasn’t so keen on hitting her colleague, and her reasoning makes a lot of sense:
That did not feel good. Because, even with the extra 30 pounds [she gained], I still would have like 20 or 30 pounds on her. So it never feels good, but she didn’t seem to care very much.
That’s putting it mildly. Still, when O’Brian expressed concern about hurting Sydney Sweeney before a particularly rough scene, the young actress brushed it off completely. O’Brian recalled:
She was like, ‘If you break my nose, that’s fine.’
Now that’s commitment to a role. The yet-untitled film wrapped production last November and is directed by David Michôd (The King) from a script co-written with Mirrah Foulkes. It focuses on Christy Martin’s incredible career, her groundbreaking success in a male-dominated sport and the darker chapters of her personal life, including surviving a near-fatal attack by her then-husband in 2010. Martin herself was present on set, something O’Brian described as both “intimidating” and “awesome.”
Sweeney, for her part, has previously shared the toll the transformation took on her body. In a W magazine interview, she talked about her body becoming “completely different” as a result of her physical transformation. Sweeney stated that it was “crazy” how her “butt got huge” and her “boobs got bigger.” Nevertheless, she found it to be an “amazing” experience, and she felt “strong” as a result of it.
Christy Martin’s legacy is already immortalized in the documentary Untold: Deal With the Devil, (which is streamable with a Netflix subscription). However, Martin’s life seems poised to gain a new layer of resonance through Sydney Sweeney’s performance and, if early behind-the-scenes anecdotes like O’Brian’s are any indication, she’s left every ounce of herself in the ring.
Meanwhile, Katy O’Brian has a few notable titles on the 2025 movie schedule and beyond. She lined up to star in the new remake of The Running Man, a movie she started right after wrapping on the boxing biopic (which may or may not have made her a bit more cautious about getting her nose broken). Fans can also still see her performance as Kodiak in Mission: Impossible – The Final Reckoning, which is in theaters now!