Sydney Sweeney made headlines last year when she shared pics from the set of her upcoming Christy Martin biopic, and now she’s revealing exactly what she did to transform into the role.

“I loved it,” Sweeney, 27, told W magazine in a cover story published Monday, June 9, noting that she gained more than 30 pounds to play Martin, now 56. “I came onboard to play Christy, and I had about three and a half months of training. I started eating. I weight-trained in the morning for an hour, kickboxed midday for about two hours, and then weight-trained again at night for an hour.”

Sweeney added that her “body was completely different” after all that working out. “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.’”

Despite all those changes, Sweeney was still a fan of her new body. “It was amazing,” she told the outlet. “I was so strong, like crazy strong.”

After filming wrapped on the as-yet-untitled Martin project, Sweeney had just seven weeks to drop the weight for her next project. Director David Mîchod was thrown by seeing his leading lady in a new light, in part because he’d never seen her in Euphoria.

“I was stunned by the change in her appearance,” he told W. “I had only seen her as an adorable, tough moppet with late-’80s hair, ready to box. Sydney was happiest when she was in the ring punching and being punched. It was shocking to see her being so glamorous.”

Sydney Sweeney is getting into character with a new look as she prepares to portray boxer Christy Martin in an upcoming biopic. “Well the cats out of the bag thanks to some paps in bushes so here’s a little bts from my film I’m working on right now,” Sweeney, 27, wrote via Instagram on Wednesday, […]

The film will follow the life of Martin’s journey to become one of America’s most successful female boxers. She began her career in 1989 after meeting her manager and later husband, James Martin. She went on to win the World Boxing female super welterweight title in 2009 and continued to box until 2012.

In 2010, Christy nearly died after being attacked by James. He was arrested and charged with attempted first degree murder and aggravated battery with a deadly weapon. Two years later, James was found guilty of attempted second-degree murder. He is currently serving a 25-year prison sentence.

Christy was the first woman boxer elected to the Nevada Boxing Hall of Fame in 2016. She was also elected to the International Boxing Hall of Fame in 2020, the first year women were included on the ballot.

According to Mîchod, Sweeney fully embodied Christy in the film, which is due out later this year.

“Sydney trained her butt off to play the part,” he told W. “The beauty of Sydney is that she turned up to work every day with her tail wagging, ready to go. No matter how tough it was, she was like a ray of sunshine.”