To play a superhero, you basically have to be superhuman.

Jennifer Garner sent that message Monday with a video of some of the work that went into that cameo — one of many — in Deadpool & Wolverine. And it was substantial.

Titled “Becoming Elektra,” the footage showed the actress whirling around with swords, jumping on mini trampolines, performing jump squats, and hopping up on boxes to throw kicks. She also swims, boxes, jogs, jumps rope, and rows. Just watching it is tiring!

Garner played Elektra the first time in 2003 Marvel film Daredevil, starring the actress’ ex-husband Ben Affleck, and she reprised the role for her own movie, Elektra, in 2005. So it’s been more than 20 years since Garner has appeared as the badass, super-skilled assassin.

“Other than trying to convince my kids’ preschool buddies that I was secretly a ninja, I hadn’t picked up Elektra’s sais since 2004,” the mother of three children with Affleck recalled on social media. “I was fit, but not @marvel fit.”

For her, playing the character again was an “impossible dream,” accomplished by having stepped up her workouts to multiple times a day and turning to a trainer.

“We had #SuperHeroSummer over here, twirling sais in the backyard and laughing at our sore old bodies,” Garner said.

Sign up for Entertainment Weekly’s free daily newsletter to get breaking TV news, exclusive first looks, recaps, reviews, interviews with your favorite stars, and more.

And, being Jen, she used the power that she gained for good.

She surprised fans at Comic-Con 2024 in San Diego last month, when she and several other Marvel veterans, such as Chris Evans (as Johnny Storm in Fantastic Four) and Wesley Snipes (as Blade from the Blade trilogy), showed up at a panel following a screening of the new Ryan Reynolds–Hugh Jackman hit.