Chris Hemsworth talks being a scientific 'guinea pig' in his Nat Geo series Limitless

·4 min read

Chris Hemsworth's new documentary series has him performing some death-defying stunts. Literally.

As Marvel's Thor, Hemsworth has spent more than a decade facing off against all sorts of superpowered foes. But for his new National Geographic series, the actor teamed up with director Darren Aronofsky to battle a different kind of opponent: the human aging process.

The result is Limitless with Chris Hemsworth, a six-part series debuting this fall on Disney+. The show follows Hemsworth as he examines the limits of the human body, collaborating with scientists to explore ways to reduce stress, maximize performance, and even halt the aging process. As part of his investigation, he also undergoes a series of frankly insane challenges, including swimming in the Arctic and dangling from a rope a thousand feet off the ground — all in the name of science.

Chris Hemsworth in Limitless
Chris Hemsworth in Limitless

Craig Parry/Disney + Chris Hemsworth in 'Limitless'

"It was one extreme after another — a series of scientific experiments where I was the guinea pig," Hemsworth tells EW with a laugh. "I was just in awe of the individuals I was working with who did this day to day. But also, I gained a beautiful understanding and appreciation for how incredible the human body and mind is, and what potential we all have."

In some ways, Hemsworth is the perfect test subject for Limitless. As a literal Marvel superhero, he's in perfect shape, and he says he's long been fascinated by the scientific capabilities of the human body. Aronofsky has a similar curiosity: When he's not directing feature films like Black Swan and the upcoming Brendan Fraser drama The Whale, the filmmaker has spent the last few years working on documentary series for National Geographic, including One Strange Rock and Welcome to Earth with Will Smith. Limitless was born out of his personal interest in mortality and the booming anti-aging industry.

"There's this very normal human fear of death that has kind of become a big point of conversation in culture right now," Aronofsky explains. "Mostly because the boomers are getting really old, and suddenly a lot of resources are going into the science of longevity. All the biggest tech companies have all these departments and wings that are looking into it."

Chris Hemsworth in Limitless
Chris Hemsworth in Limitless

Craig Parry/Disney + Chris Hemsworth in 'Limitless'

The director points to his 2006 film The Fountain as an example of his longtime fascination with the subject. "There was this one throwaway line in The Fountain, which is, 'Death is a disease, and I'm going to cure it,'" Aronofsky adds. "I remember when that line was in the movie, I debated if it was just too crazy of a line to stick in the film and [whether] people would think it was ridiculous. Now, it seems like lots of people are taking it seriously."

Much of the show focuses on the physical aspects of longevity. Hemsworth's journey takes him around the world, as he meets with researchers and experts to probe some of the latest science. It's an experience he calls "terrifying at times," but also "exhilarating, exciting, and humbling." In one sequence, he explores how stress affects the body by diving into a deep pool with his hands tied, attempting to hold his breath underwater for minutes at a time. In another, he has to carefully walk across a towering skyscraper crane, suspended thousands of feet above the ground.

Chris Hemsworth in Limitless
Chris Hemsworth in Limitless

Craig Parry/Disney + Chris Hemsworth in 'Limitless'

But despite all the heart-pounding stunts and physical challenges, there's also a pensive thoughtfulness to the series, as Hemsworth grapples with ideas of death and mortality. Both the actor and Aronofsky are careful not to spoil the final episode, but it finds Hemsworth facing the aging process head on in a sequence that's both sweetly funny and deeply emotional.

"One very surprising thing that was a great gift to the show was Chris' openness to be honest and transparent," Aronofsky adds. "I think you get to see a side of Chris that people have never seen before."

Chris Hemsworth in Limitless
Chris Hemsworth in Limitless

Craig Parry/Disney + Chris Hemsworth in 'Limitless'

One of Hemsworth's most challenging moments was that icy swim in the frigid waters of Norway. The actor was joined by his two brothers Luke and Liam as he journeyed to the Arctic, and there, he had to ignore his own body's protests and try to make his way through freezing waves. "That was a super hard, scary experience," Aronofsky says. "It was really dangerous. You're asking Chris Hemsworth, one of the biggest stars in the world, to take an Arctic swim. To see him rise to that occasion was spectacular."

And although Hemsworth says he's proud of the accomplishment, next time, he'd prefer to stick to warmer waters.

"Immediately, I was like, 'Never again,'" he says with a laugh. "I ticked the box. I do plenty of ice baths, but there's something different about putting your head under the water at the same time. If there was an emergency, there'd be something familiar about it. But for fun? Nah."

Make sure to check out EW's Fall TV Preview cover story — as well as all of our 2022 Fall TV Preview content, releasing over 22 days through Sept. 29.

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