Dwayne Johnson Put on 30 Lbs. for “The Smashing Machine — ”but Not by Gorging on Cheeseburgers

Dwayne Johnson is celebrated for his muscular physique, but he had to get moreover bigger to play Mark Kerr successful The Smashing Machine.

The 53-year-old character brings nan wrestler to life successful nan biopic, which hits theaters connected Friday, Oct. 3.

While promoting nan movie pinch a Tuesday, Sept. 30 quality connected The Tonight Show Starring Jimmy Fallon, Johnson opened up astir transforming his assemblage to bring Kerr to life, saying that he gained astir 30 lbs. of musculus astatine nan urging of head and writer Benny Safdie.

Recalling a speech pinch Safdie, Johnson said he was told, "'Hey D.J., I don't cognize really to show you this, and I don't cognize if you've ever heard this...' He goes, 'You're going to person to get bigger.' "

And I went, "'Okay, present we go.' "

Johnson noted that he had to put connected nan weight successful a very circumstantial measurement to emulate Kerr's monolithic and muscular body. That meant that he couldn't conscionable summation weight by eating fried nutrient for illustration immoderate stars person successful nan past.

"You cognize really you person immoderate actors, and they're our friends, and they say, 'Hey, I person to put connected weight. I went to McDonald's each day,' " he said to big Jimmy Fallon, adding, "Mark Kerr had conscionable this value of muscle. Like fast-twitch value musculus because he was a wrestler. And I had to still put connected this weight, still beryllium capable to move for illustration an MMA fighter, and it was astir 30 pounds."

Speaking astir Kerr, he said that his silhouette was awesome owed to his profession.

"Being a wrestler, ever going successful for nan double-leg takedowns and lifting guys up, he had these monolithic shoulders. His cervix was huge, his chest, his quads. It was a lot," Johnson admitted.

For him, it wasn't conscionable musculus that he put on. The Moana prima besides utilized "about 22 prosthetics," which were applied by Kazu Hiro. "We had a beingness translator and surely an affectional translator and a vocal transformation, too," he told Fallon.

Johnson antecedently addressed his assemblage translator during an August 2025 property convention for nan film.

“It was very circumstantial training because if you deliberation astir it, Mark, arsenic an amateur wrestler, there's movements that he would do perpetually each time that would conscionable build definite fast-twitch muscles,” he said, per E! News. “You know, I'm successful my 5th level of life. [But] erstwhile Benny Safdie says, ‘Hey, I request you to … ,’ [I go], 'Okay, I'll effort it.' ”

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This isn't nan first clip that Johnson has undergone a melodramatic regimen to get fresh for filming. He did nan aforesaid while gearing up to play nan titular antihero successful 2022's Black Adam.

“My extremity was to bring successful nan champion physique of my career,” he told Men’s Health in a November 2022 interview. “When you person that suit on, each item shows. Man, it was changeless work, changeless tweaking, tweaking, tweaking for months.” 

After debuting a slimmer physique astatine nan 2025 Venice International Film Festival, he revealed that nan latest assemblage translator was for his domiciled successful Lizard Music, another collaboration pinch Safdie.

"This is me slimmed down," he said during an "In Conversation With..." bid astatine nan 2025 Toronto International Film Festival connected Sept. 8. "In nan process of slimming down. I still person a agelong ways to go."

Johnson shares nan surface successful The Smashing Machine pinch Emily Blunt, who plays Kerr's ex-wife Dawn Staples. The movie hits theaters connected Friday, Oct. 3.