If you follow Brie Larson on social media, chances are you’ve caught a glimpse into her newfound workout regiment, which was kicked into high gear when she was cast as Carol Danvers in the highly anticipated superhero origin adventure Captain Marvel. (Watch the film’s brand-new trailer above.)

Some of the newly ripped Larson’s most extreme feats of strength have not been shared for public consumption, however, like one particularly insane video that shows the 29-year-old actress grunting and groaning as she pushes — no joke — a Jeep up a hill. Thanks to Larson’s co-star Samuel L. Jackson, Yahoo Entertainment was among a small army of outlets that got a private screening of Larson’s Iron Woman imitation, which included another video showing her easily hoisting 350 pounds, when we visited a couple of the film’s Los Angeles sets this past spring. We were not the only ones he’s played them for.

“Oh my gosh. He showed those to you?” an awestruck Larson, who won an Academy Award for her stunning breakout performance in the 2015 drama Room, said when we brought them up. “I can’t believe it. I feel like I’m close to 100 people that have come up to me and been like, ‘I saw this video that you sent Sam.’ It’s so embarrassing. I sent that to him in private. He actually showed the person that was next to him on a plane, too. Which I found out later. ‘Oh, I sat next to Sam who you sent that video and he showed it to me.’ I was like, ‘Why?'”

16 PHOTOS Brie Larson See Gallery Brie Larson Actress Brie Larson holds her award for Best Actress in a Leading Role for the film "Room" during the Vanity Fair Oscar Party in Beverly Hills, California February 29, 2016. REUTERS/Danny Moloshok Brie Larson accepts the Oscar for Best Actress for her role in "Room" at the 88th Academy Awards in Hollywood, California February 28, 2016. REUTERS/Mario Anzuoni Best actress Brie Larson, "Room", reacts during the 88th Academy Awards in Hollywood, California February 28, 2016. REUTERS/Mike Blake Actress Brie Larson poses at the AFI (American Film Institute) Awards 2015 luncheon in Los Angeles, California January 8, 2016. REUTERS/Mario Anzuoni Actress Brie Larson poses at the BAFTA Los Angeles Awards Season Tea Party in Beverly Hills, California, January 9, 2016. REUTERS/Danny Moloshok Brie Larson poses with the award for Best Performance by an Actress in a Motion Picture - Drama for her role in "Room" during the 73rd Golden Globe Awards in Beverly Hills, California January 10, 2016. REUTERS/Lucy Nicholson Actress Brie Larson arrives at the 2014 Vanity Fair Oscars Party in West Hollywood, California March 2, 2014. REUTERS/Danny Moloshok (UNITED STATES TAGS: ENTERTAINMENT) (OSCARS-PARTIES) Actress Brie Larson gives her acceptance speech after winning her Best Female Lead award for her role in "Room" at the 31st Independent Spirit Awards in Santa Monica, California February 27, 2016. REUTERS/Carlo Allegri Actress Brie Larson arrives at the 88th Academy Awards nominees luncheon in Beverly Hills, California February 8, 2016. REUTERS/Mario Anzuoni Actor Brie Larson, Jacob Trembley and Joan Allen arrive for the premiere of the movie "Room" during the 40th Toronto International Film Festival in Toronto, Canada, September 15, 2015. TIFF runs from September 10-20. REUTERS/Fred Thornhill Actress Brie Larson poses for a portrait while promoting her upcoming movie "Room" in Los Angeles, California September 30, 2015. Picture taken September 30. REUTERS/Mario Anzuoni Cast member Brie Larson poses at the premiere of "Don Jon's Addiction" during the Sundance Film Festival in Park City, Utah January 18, 2013. REUTERS/Mario Anzuoni (UNITED STATES - Tags: ENTERTAINMENT) U.S. actress Brie Larson arrives for the premiere of Scott Pilgrim vs. the World at the Empire Theatre in London August 18, 2010. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY) Cast member Brie Larson attends the premiere of the film "Greenberg" in Los Angeles March 18, 2010. REUTERS/Phil McCarten (UNITED STATES - Tags: ENTERTAINMENT) Actress Brie Larson smiles during the news conference for the film "Rampart" at the 36th Toronto International Film Festival September 11, 2011. REUTERS/Mike Cassese (CANADA - Tags: ENTERTAINMENT HEADSHOT) Cast member Brie Larson poses for a portrait while promoting her upcoming movie "Short Term 12" in Los Angeles, California August 6, 2013. REUTERS/Mario Anzuoni (UNITED STATES - Tags: ENTERTAINMENT) Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

Larson paused, then answered her own question: “He knows it was … I came from humble beginnings.”

Though Larson parlayed breakout turns in films like Short Term 12 and awards buzz in Room (a part she added 15 pounds of muscle for) into a starring role in Universal’s 2017 monster tentpole Kong: Skull Island, her entry into the Marvel Cinematic Universe has marked the first time she’s had to get into super-shape.

Captain Marvel, co-directed by Anna Boden and Ryan Fleck (Half Nelson, Mississippi Grind), is a mid-90s-set origin story that follows the former Air Force pilot Danvers on her intergalactic exploits with Starforce as the alien races Kree and Skrulls clash, and leading up to her introduction to future S.H.I.E.L.D. boss Nick Fury (Jackson).

Jackson, in his third collaboration with Larson (not counting her famous logo’s appearance at the end of Avengers: Infinity War), was wowed by the transformation he saw in the year since she’d won the role. “The girl that I did Kong and Unicorn Store with is not this person,” he said. “She’s like 5 percent body fat now… She’s made a distinct transformation that I don’t think a lot of people would be willing to do. It’s a huge commitment to do stuff like that.”

Larson said there wasn’t one particular sequence that required such rigorous training. “It really all came out of ignorance, to be honest. I didn’t realize that you don’t actually do your own — or most people don’t do their own — stunts in these movies. I thought you did, and I’ve never been a particularly elegant or athletic person. I’m just an introvert with asthma, and felt like I needed to be able to do that. I just thought, ‘I don’t wanna be on set, and they ask me to do things, and I don’t know how to do it.’ So I started training as soon as I could, which was right after I locked picture on the film that I directed [Unicorn Store, which premiered at the 2017 Toronto International Film Festival]. I then went into that, which then turned into nine months of training. And nine months of just training-training, and three months of stunt training with the stunt team. We spent two hours every day, five days a week.

“It wasn’t until we started shooting, and I started doing all my own wire work stunts, and flips and stuff that people were like, ‘Now we’ll tell you: Nobody actually does this. We just didn’t want you to stop. But now that you’ve kind of accomplished this thing, we don’t normally do this.’ And I was like, ‘Huh?’ But I love it. I mean it definitely makes things more complicated in certain ways, because I could be taking a lot more naps than I am. I could just be like, “Renee and Joanna [her stunt doubles] got it, I’m gonna go eat some cake.’ But instead it’s really become a huge part of how I learned more about [Captain Marvel], and became her, and embodied her. [It] was through that, [it] was through discovering my own strength.”

As for the Jeep stunt, specifically, “It was a joke,” Larson said coyly. “It was a joke with my trainer, Jason Walsh… I spent nine months training with him ahead of time, and I was like, ‘Well, she can move planets, the least I could do is move a car.'”

Larson might’ve been joshing, but her Rise Nation trainer Walsh was not. “I just showed up in the gym one day and he was like, ‘All right, let’s do it.’ And I pushed the car, yeah. And it wasn’t as hard as I thought, which was kind of crazy. There was someone in the front seat in case for some reason, the car’s in neutral, but it’s going uphill. And I pushed it for a minute. Someone was in the car in case I crapped out, so it wouldn’t run me over. There was someone waiting there to put their foot on the brake.”

The actress, in true powerful/responsible superhero mode, offered a cautionary warning: “Don’t try it at home. Really don’t,” she said. “It’s really probably not a safe thing to do. But it felt supersatisfying, and I felt really crazy afterwards. Because when you do stuff like that… I had never lifted weights, or done things [like that] until this movie. So you get these crazy highs, and then you just kind of collapse onto the floor.”

But not before you text Sam Jackson – which you may live to regret.

Captain Marvel opens on March 8.