The Rock spent 18 months gaining muscle and losing fat to achieve a 'comic-book look' for 'Black Adam.' Here's how he did it.

The Rock spent 18 months gaining muscle and losing fat to achieve a 'comic-book look' for 'Black Adam.' Here's how he did it.
Dwayne Johnson in "Black Adam."Frank Masi/Warner Bros. Entertainment Inc.
  • The Rock ate seven meals a day and trained six days a week, his strength coach said.
  • It took 18 months to gain his goal amount of muscle for "Black Adam" and minimize body fat.

Dwayne "The Rock" Johnson took his physique "to a whole other level" for his starring role in DC's "Black Adam" with over a year of careful training and nutrition, according to Dave Rienzi, his strength-and-conditioning coach.

For an already-ripped athlete like The Rock, packing on extra muscle while staying lean takes time, tons of calories and protein, and smart, intense workouts, Rienzi, who is also the cofounder of Johnson's energy-drink brand ZOA, said.

Rienzi's video series, "Building Black Adam," shares more details about the specific workouts in Johnson's training.

"Everyone is always asks 'He's already so fit, what more can you do?' He's the only actor out there who, in real life, looks like a superhero," Rienzi told Insider.

"We really focused on his proportions and symmetry and obviously we wanted to add more muscle to his physique and really get the comic-book look with three-dimensional muscle."


The Rock's 'Black Adam' transformation took 18 months

Johnson's training for the film included a full year dedicated to building mass, since muscle takes time to grow, followed by six months of focus on muscle definition and leanness. Rienzi did not specify how much muscle they wanted to add.

Rienzi said slow, steady gains were crucial to help create a massively muscular look without putting on excess body fat, since Johnson was filming other projects while training and needed to keep his appearance consistent.

"We can't have crazy fluctuations, so I took a much longer approach," he said.

His fat-burning phase involved fasted cardio and interval training

To maximize muscle building, it's important to have a calorie surplus, or eating more than you burn off. As a result, some extra body fat is almost inevitable as you make gains.

To keep him lean, Rienzi had the Rock doing "fasted" cardio and hitting the StairMaster before breakfast to burn fat.


He also gradually increased the intensity of his routine closer to filming, adding 30-second sprint intervals followed by two minutes of steady effort.

"That really cranked up the fat burning," Rienzi said.

He ate 4,000 to 6,000 calories a day during the process

Johnson has previously said his typical diet is up to 6,000 calories a day. To get him shredded for "Black Adam," the final fat-burning phase of his diet included around 4,000 calories, with nearly 500 grams of protein daily to help him hold onto muscle while getting leaner, Rienzi said.

The Rock also needed 5,000 calories a day to maintain the physique during filming, and Rienzi said his food through the process was strictly measured to keep him on track.

To get enough fuel, Johnson eats about seven meals a day, as well as post-workout supplements like creatine, according to Rienzi.


"He's drinking a protein shake while walking out of the gym, and then typically he's eating a whole-food meal about an hour later," he said.

Johnson trained nearly every day to build and maintain muscle

Since the Rock is already massive, Rienzi said the main focus of his training was giving his muscle the right proportions for a superhero, using a workout split dedicating each of his six days of training to different muscle groups.

"When you look at a superhero type physique in the comic books, it's always big round shoulders, a wide back with a narrow waist and round chest," he said. "We did a lot of heavy back training to create more width and that V-taper look we were going for."

To push an experienced athlete like Johnson, Rienzi used special techniques to increase the difficulty and muscle tension, including static holds, negatives, and pause reps.

The Rock spent 18 months gaining muscle and losing fat to achieve a 'comic-book look' for 'Black Adam.' Here's how he did it.
Courtesy of ZOA

Maintaining his physique for filming was the biggest challenge

Rienzi said the hardest part of "Black Adam" training was keeping The Rock huge during filming.


"We did all that work ahead of time and had five to six months of shooting to maintain the physique, which is extremely challenging because he's working 12-hour days," he said. "We were constantly in contact, tweaking his training, watching his nutrition."

In most cases, the ripped physique you see on movie stars or bodybuilders is only for a brief "peak" period during filming or competition, since a super-lean and muscular look takes intense discipline that isn't sustainable for long periods of time.

Johnson has two shirtless scenes in "Black Adam," which Rienzi said were shot six weeks apart, requiring him to look his best throughout. Despite the difficulty, the hard work paid off.

"Seeing the transformation on-screen, the scenes are iconic. I was blown away, and I was on set with him for those scenes," he said.