Trainer Reveals Grueling Regime that Forged David Corenswet into DCU's Superman

As the highly anticipated DCU reboot of Superman inches closer, fans are getting their first glimpse into the arduous process that transformed actor David Corenswet into the iconic Kryptonian superhero. In a revealing interview with GQ, personal trainer Paolo Mascitti, who guided Corenswet through his physical transformation, lifted the veil on the actor’s grueling journey to become the Man of Steel.

According to Mascitti, Corenswet, known for his lean physique, needed to pack on significant muscle mass to fill out the iconic Superman costume envisioned by director James Gunn. This ambitious goal required a meticulously designed regimen that saw the 6’4″ actor consuming a staggering 6,000 calories per day, propelling his weight from around 200 pounds to a formidable 240 pounds.

“This is a James Gunn film, and he has a specific vision of the entire project. David had been working out intensively before I met him, but he’s naturally a very lean guy. He’s 6’4″ but we wanted to put more bulk on him. He probably went from 200lbs to 240lbs, but some of that mass will be shed as he continues to tone up,” Mascitti explained.

The transformation process began five months before production, with Corenswet dedicating himself to intense two-hour workouts three to four times a week, even as filming commenced. Mascitti’s approach focused on tried-and-true methods, incorporating a classic push-pull-legs split and exercises like presses, pull-ups, rows, and other compound movements.

“This is just what works. A lot of trainers online are looking for the next best thing, but it’s not about showy moves, it’s about mastering the exercise and focusing on things like full range of motion, mastering the negative, stretching, and trying to progress in weight and reps,” Mascitti stated, emphasizing the importance of mastering the fundamentals.

While the physical demands were undoubtedly challenging, Mascitti praised Corenswet’s dedication and natural affinity for the role, declaring him the embodiment of Superman. “He is Superman. James Gunn is amazing at casting people, and this guy was born to be Superman. Ask any cast or crew member, David is the nicest guy, and I think, the perfect Superman.”

Mascitti also highlighted Corenswet’s playful spirit and realistic approach to the role, recounting instances where the actor would indulge in cereal despite his strict diet, embodying the relatable humanity that makes the character so iconic.

The trainer further revealed a friendly rivalry between Corenswet and his co-star Nicholas Hoult, who portrays Lex Luthor in the film. Mascitti praised Hoult’s dedication in the gym, describing him as someone who “pushes himself and pushes himself” and can “do absolutely everything” when it comes to workouts.

As anticipation builds for the DCU’s reimagining of the iconic superhero, Corenswet’s transformation stands as a testament to the commitment and hard work required to embody such a beloved and powerful character. With James Gunn at the helm and a dedicated team behind the scenes, fans can look forward to witnessing a fresh and dynamic take on the Man of Steel when “Superman” hits theaters on July 11, 2025.