Trainer Magnus Lygdbäck on Alexander Skarsgård's Northman Workout

The path to Alexander Skarsgård's role of Amleth, a Viking warrior prince bent on revenge in The Northman, was set long ago. The actor told Vanity Fair that he had dreamed of making a film based on Icelandic sagas since he was a child visiting his grandfather on a Swedish isle, hearing stories of its earlier inhabitants. But once the project became a reality, the 6'4'', 45-year-old Swede had to transform his body to fit the part. Thankfully, Skarsgård is no stranger to molding his body for a film, having shredded down to play the title role in 2016's The Legend of Tarzan. He turned to the same man to build up his Northman body: fellow Swede Magnus Lygdbäck.

The film's subject matter (and pedigree with auteur director Robert Eggers on board) made Lygdbäck especially conscious of the work it would take to develop Skarsgård's physique for the film. "Being Swedish, I know the history of Vikings," the trainer told Men's Health on a Zoom call. "I knew this was going to be an important movie because it's an authentic Viking movie—you can argue it's the first authentic Viking movie. And I know Alex have been working on this project for a long time, and I just waited to get the call [to work together on the film]. I was really, really excited when I did."

Lygbäck, who has also worked with Ben Affleck and Gal Godot, among others, says the physical prep for The Northman—or any other beefed-up role for any of his clients—starts at the most basic level. "It's always about building a character," Lygdbäck said.

For Skarsgård's portrayal of Amleth, that meant digging deep into the actor's subconscious and getting in touch with his animalistic instincts. "His spiritual animals in this movie is a wolf and a bear. He's a wolf-bear," Lygbäck said. "So we needed him to move and be agile like a wolf, and we need him to look like a bear."

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Aidan Monaghan

In terms of build, this meant that the end goal was to make Skarsgård thicker and more muscular so that he would be "imposing." Anyone who has seen the film's trailer will recognize the result; there's one specific moment as Skarsgård stalks through the frame in the midst of a raid, shoulders hunched and holding a pair of weapons, that he almost appears to be hunting prey like one of his wild inspirations.

Movement was an important component in creating the character, too. This was especially essential because of Skarsgård's age (again, he's 45) and Eggers' exacting shoots. "[Eggers] loves those long takes, and there's so many things that need to be perfect. So I knew that Alex needed not only to look the part, but move the part," Lygbäck said. "There's no CGI, there's no different angles, where you can cut from one angle to another to save the look of a movement. It's very pure, and it all needs to connect." Lygbäck said he would work specifically on the way the character would move in Skarsgård's strength training sessions, with additional focus on the side (Lygdbäck says he also worked with the other actors playing bersekers, elite Viking warriors, in their training).

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Aidan Monaghan

Actor Alexander Skarsgård and trainer/nutritionist Magnus Lygdback on the set ofRobert Eggers Viking epic, THE NORTHMAN, a Focus Features release.

The strength training sessions were focused on packing on muscle—but Lygbäck and Skarsgård were slightly limited in what they could do, as the bulk of the shoot took place at the height of the Covid-19 pandemic when gyms weren't always accessible. They built out a makeshift training facility in the actor's garage, which led to using versatile training tools like battle ropes (which Lygbäck admits aren't typically in his training repertoire), landmines, and more in lieu of machines and super heavy weights. This was all in service of strengthening Skarsgård's shoulders, hips, and core—all important for swinging an axe.

Check out the series below for a sampling of the workouts Lygdbäck designed for Skarsgård to embody Amleth, the wolf-bear Viking warrior prince. For more, the trainer offers a complete program on his app. To see the finished product, don't miss The Northman in theaters starting April 22.