Then: Heavy Lifting

Like any celebrity fitness transformation, Momoa relied on heaving heavy metal to build more muscle, with no shortage of grueling workouts. For 2017’s Justice League and 2018’s Aquaman, Momoa worked with trainer Mark Twight, who famously helped Henry Cavill get ripped to play Superman in Man of Steel and Batman v. Superman: Dawn of Justice.

Momoa did heavy renegade rows and dumbbell raises, battle ropes work, and pullup ladders before maxing out with bench presses.

Now: Functional Free Weight Work

“I still get tempted from time to time to max lift and add those two extra plates on, but that’s when I need to have a conversation with myself and make sure I don’t do something that’s going to do more damage than good,” Momoa says. “I’ve got a little more wisdom now. I’ve been through this dance for 45 years.”

Momoa will lift when he’s getting ready for a movie like Aquaman 2, but typically relies on dumbbells and cable machines.

However, there is one exercise he doesn’t think he’ll do again: flat bench press.

“It just does’t make sense for me to do that anymore,” Momoa confesses. “There are so many other things that are better for my all-around strength and ability to perform.”

Now and Forever: Kettlebell Complexes

“I find training with kettlebells and resistance bands very nurturing,” Momoa reveals. “The moment I discovered kettlebells, it was a game-changer.”

In part that’s thanks to Damian Viera, Momoa’s personal trainer and healer. In a 2021 interview with Men’s Journal, he said he programmed kettlebell ladder workouts for Momoa to actively engage and strengthen his muscle tissue. Jason would do a series of two-handed squats, two-handed deadlifts, two-handed swings, one-handed swings, and one-handed cleans.

Now, he’ll work with heavy kettlebells to maximize time and work multiple muscle groups and energy systems. He’ll use an 88-pound (40-kg) and 124-pound (56-kg) kettlebell to do split squats, sumo squats, and kettlebell swings, and go a little lighter for single-arm presses and Turkish getups.

In the past, he avoided isolated exercises for his legs. “I’m part Hawaiian, and genetically that means if I train legs even just a little bit, they get huge,” he says. But kettlebells are able to torch his lower body, work his core, and get everything really strong and powerful without lifting heavy or blowing up.

“I don’t have much time these days, so it’s about how quickly and how powerfully I can bang it out,” Momoa says.

Then: Working to Failure

It’s easy to get carried away and to think optimal fitness means firing on all cylinders 24/7: one more rep, one more plate, one more day.

“I’ve had so many injuries over the years that now I’m more interested in the exercises that take care of me as much as they make me strong,” Momoa admits.

Jason Momoa eating a carrot in his home greenhouse, where he grows squash, eggplants, carrots, basil, kale, arugula, and collard greens.

Jeff Lipsky for Men’s Journal

Now: Prioritizing Rest and Training for Longevity

“Being injured is such a downer—such a drain, mentally, especially when you enjoy getting after it,” Momoa says.

But it’s those memories of being sidelined that keep him in check from doing something he probably shouldn’t be attempting. Rather than abusing his body and seeing how far he can push his limits, Momoa is focused on training to feel good.

“I’ve also realized that I get bigger after my workouts the more I rest,” he says.”It’s not about pounding myself with workouts over and over again. If I take two days off, I come back stronger.”

Then: Training for Aesthetics

It’s no surprise that looking the part of a DC Comics superhero isn’t the most sustainable.

“If what I’m doing is all about trying to look unnatural, then the chance of being able to keep it together gets a lot more difficult,” Momoa says. “You can see it when a bodybuilder cheats on their diet or loses focus for just a week or so.”

While it looks like Momoa lives in the gym, he’s not a fan of traditional strength training methods.

Jeff Lipsky for Men’s Journal

Now: Training for Dynamic Athleticism

Rather than being super strict about the training and building superficial muscles, Momoa’s fitness hinges around feeling as good as he looks.

“If you try to accomplish a strong but natural physique for yourself, it’s going to be a lot better in the end,” Momoa says, “and it’s going to be a lot easier to maintain the whole year through, which is how long some of these productions take.”

For Momoa, rock climbing has always provided an immense amount of joy that, thankfully, translates well into his training.

“Climbing serves as movement therapy,” Viera says. It’s a great way for Momoa to test himself with problem-solving, but also keep his body pliable so injury is prevented when he needs to go into dynamic movements.

Speaking of which, medicine balls have also been a great way to train power and add muscle while fostering athleticism.

For the first Aquaman film, Viera worked in a lot of medicine ball exercises using 10-, 15-, and 20-pound Dynamax balls to keep Momoa moving well with Aquaman’s trident. They worked through isolated chest passes, hammer rotations, bilateral passes, and more.

Momoa throwing axes at home.

Jeff Lipsky for Men’s Journal

Now and Forever: Enjoying the Process

There are so many ways to work out while enjoying life.

“You can get burnt out super easily if all you do is lift things just to put them down,” Momoa says.

Doing the things you love, then throwing in a little weight training here and there is the way to make a healthy lifestyle stick.

“Keeping good people around who love to train and inspire me is a huge part of being successful as well,” Momoa adds.

To that end, Momoa’s been leaning into boxing with Ian Streetz, even bringing him to the Minecraft movie while filming.

“I don’t get to box as much as I would like to, because we’re so busy, but I love when I get to throw some hands and my kids love to box, too,” Momoa says. “My daughter is such a hammer. I’m not going to have to worry about her at all.”