Sydney Sweeney Details Grueling Weight Transformation For Boxing Biopic

Sidney Sweeney She underwent an exhausting transformation for the boxing biopic Christie, and gained 30 pounds through intense training for the film’s shoot. Christy Martin.

The actress has now revealed that losing all that weight to return as Cassie Howard in ‘Euphoria’ was both physically and mentally demanding on her.

“Christie” debuted to just $1.3 million, but Sidney Sweeney emphasized its impact, highlighting its message of survival, courage and raising awareness of domestic violence.

Sweeney spoke candidly about the extreme physical and mental challenges of transforming her body for the upcoming boxing biopic “Christie” while quickly returning to her role in HBO’s “Euphoria.”

It portrays Christy Martin, one of America’s most famous female boxers in the 1990s, whose career was later overshadowed by the 2010 attempted murder of her husband.

To portray Christie, Sweeney undertook a grueling three-month training program, training three times a day and gaining 30 pounds to reach the boxer’s fighting weight of 135 to 137 pounds.

Her preparations included some unusual snacks, such as frozen jam sandwiches known as Uncrustables.

Co-star Ben Foster, who plays Christie’s promoter husband Jim, also gained weight for the role, leading to a humorous moment where Sweeney mistakes his natural double chin for a prosthetic.

“I think it was the second week when Syd came over and started touching my double chin… She was like, ‘This prosthesis looks really good.’ “And I said, ‘That’s not a prosthesis,’” Foster recalls. Daily Mail.

However, just weeks after completing this transformation, Sweeney had to shed excess weight in just seven weeks to resume filming for Euphoria, returning to her role as Cassie Howard.

talking to The Guardianthe Emmy-nominated actress described the process as mentally and physically draining.

“It was definitely a mental challenge and almost a physical withdrawal from being able to exercise so much, which was a weird drop of serotonin,” she said. “I had to stop everything and shed all the weight,” she said, adding that she felt “the strongest, fullest version of myself.”

Despite the nerves, Sweeney said she loved undergoing the transformation for the biopic.

In an interview with Delivery time“I really felt the power of Christy when she transformed. I really enjoyed being able to train and work with the amazing boxing coaches, weight coaches, and nutritionists who helped me get to where I was for Christy,” she explained.

Sweeney also revealed that her intense diet includes “a lot of Chick-fil-A, milkshakes, Smucker’s, and protein shakes.”

Sweeney’s dedication to her role as the iconic female boxer has already earned praise from Christy Martin herself.

talking to Daily Mail Ahead of the 2025 International Boxing Hall of Fame parade in Canastota, New York, Martin described the actress as a “perfectionist” who took the boxing and domestic violence aspects of the role seriously.

“She was really serious about boxing,” Martin said. “By filming domestic violence, she wanted to make sure everything was okay.”

The actress also turned heads at the London Film Festival premiere last month, where she stunned in a pink Alexander McQueen dress featuring a delicate lace neckline, sequins, ruffles and a flowing train.

“Christy” is set to premiere in the UK on November 28, and currently holds a 72% rating on Rotten Tomatoes, with critics and fans already buzzing about Sweeney’s transformative performance, which could be Oscar-worthy.

Despite critical acclaim, “Christie” had a disappointing start at the box office.

The R-rated biopic opened with just $1.3 million over the weekend, marking one of the weakest U.S. openings for a film released in more than 2,000 theaters.