Sydney Sweeney traded glitter for gloves to embody boxing icon Christy Martin, and the transformation is jaw dropping. From a 4,000-calorie regimen to months of bruising sparring, the Euphoria star defied Hollywood beauty rules, and the rapturous TIFF 2025 ovation hints this could be her defining turn. What did it really take to step into Martin’s power, in the ring and beyond?
Bulking up on a high-calorie plan and pounding mitts before dawn, Sydney Sweeney built a fighter’s frame to inhabit boxing icon Christy Martin. With a nutritionist, a strength coach, and a boxing coach in her corner, she trained through bruises and relentless drills to nail Martin’s style, including a recreated clash with Laila Ali. The transformation landed at the Toronto International Film Festival with a standing ovation. Now the buzz is building fast, with some eyeing a 2026 Oscar run for Sweeney’s knockout turn.
From Euphoria to the Ring
Sydney Sweeney is swapping Rue’s world for the ring. The 27-year-old star of HBO’s Euphoria leads Christy, a biopic about boxing legend Christy Martin, produced by Black Bear Pictures. The film tracks Martin’s explosive rise and the personal battles she fought outside the ropes, including discrimination in a male-dominated sport and the violence she survived at home. After a buzzy trailer, Christy made its world premiere at the Toronto International Film Festival in September 2025. Sweeney frames the role as a chance to stretch into athletic storytelling. She says the assignment demanded precision, not just passion.
The response was electric. A festival crowd delivered a standing ovation that stretched on, and a teary Sweeney thanked fans during the post-screening Q&A for embracing a story that means so much to her. She credited Christy Martin and generations of women fighters for making the moment possible, as clips from the premiere raced across social media.
The Boxing Diet and Training
To become the Coal Miner’s Daughter of boxing, Sweeney started where it matters most: fuel. Under a dedicated nutritionist, she ate up to 4,000 calories per day, prioritizing lean proteins, complex carbs, healthy fats and relentless hydration. “It was the opposite of what Hollywood usually tells you about beauty standards,” she told Variety. The goal was strength, not shrinkage, and the results show on screen. The plan evolved with training loads, keeping energy high while building functional mass.
Training matched the menu. Working alongside a boxing coach and a strength team, Sweeney lived in the gym for six months, drilling stance, footwork and Christy’s compact power. She sparred daily, lifted heavy and ran intervals to mimic fight-night adrenaline. The production even staged a recreated bout with Laila Ali, a sequence Sweeney called nerve-racking yet exhilarating. She also immersed herself in Martin’s psyche, studying interviews and fights to capture resilience forged through real trauma. Bruises came with the job, but so did confidence.
TIFF Ovation and Oscar Buzz
Early reviews out of Toronto highlight the physical credibility and the emotional punch. Journalist Marguerite Lania noted how the crowd reacted to each combination, then fell silent for the bruising personal scenes. Industry chatter is already building into Oscar buzz, with Sweeney floated as a 2026 Best Actress contender. For buyers and critics, Christy looks like a crowd-pleaser with teeth.
As of September 12, 2025, Christy is the conversation piece of TIFF. For Sweeney, the transformation was more than muscle; it was discipline, vulnerability and respect for a trailblazing fighter. If the momentum holds, this could be her career-best turn and the performance that moves her from rising star to awards-season heavyweight. Now the question is how Academy voters respond once the film widens beyond the festival circuit.