When Jodie Foster, 61, signed on to play trainer Bonnie Stoll in the Oscar-nominated movie Nyad, she had just wrapped filming on a decidedly different film, one where she played a slim, suited-up lawyer. She told the film’s directors that she planned to start training immediately, they told the Washington Post.

“We never really heard anything more from her,” Jimmy Chin, who directed the film alongside his wife Elizabeth Chai Vasarhelyi, told the Washington Post. “And then she showed up just ripped.”

Nyad follows the true story of marathon swimmer Diana Nyad (played by 65-year-old Annette Bening), who impressively swam 110 miles from Cuba to Florida in 2013. Diana was 64 when she completed the feat with the help of her close friend, former girlfriend, and trainer Stoll. Both Annette and Jodie are up for Oscars for their performances.

Jodie spent months intensely preparing her body.

Jodie, 61, dedicated the months between booking and filming to training in the gym and spending time with athlete and racquetball pro Bonnie. Bonnie, 71, is described in the Post as a woman who does 100 reps of shoulder, biceps, and ab moves per day, power walks for two hours, and does military-style chin-ups and pull-ups, so Jodie definitely had her work cut out for her.

According to the Post, Jodie worked out daily before and during filming. She alternated between kettlebell drills and heavy weightlifting, eating a strict diet of mostly brown rice, chicken, and broccoli. After filming wrapped, she told Bonnie Stoll, “I hope I never see chicken again,” per the newspaper.

It seems all her training paid off, as Jodie is incredibly strong in the film, which was filmed in both open water and a tank, with limited use of stunt doubles, per The Straits Times.

Both Jodie and Annette worked hard to shatter illusions about limitations for aging women, which shines through in the triumphant story and in their physical transformations. “It was important to both actors that we not touch their bodies, as in touch up,” Vasarhelyi told the Washington Post. “They were committed to play women of their age.”

The Post reported that part of what motivated Jodie to join the film’s cast was the chance to portray, alongside Annette, older women who were “badasses.”\

Jodie has approached aging the candor and vulnerability for years.

In a conversation with Interview Magazine, Jodie says she had a difficult time in her fifties but really found a new perspective in her 60s.

“I was struggling in my fifties. I was sort of like, ‘Am I ever going to do anything meaningful again? Is this all there is?’ And there’s that awkward phase where everybody who’s in their late forties or fifties is very busy getting all plumped and shooting shit into their face. I didn’t want that life, but I also knew that I couldn’t compete with my old self,” Jodie shared. Once she hit the milestone age of 60, she saw things in a more positive light.

“There was something about going back to the work with a different attitude, I think. About really enjoying supporting other people and saying to myself, ‘This is not my time. I had my time. This is their time, and I get to participate in it by giving them whatever wisdom I have.’ Somehow it’s so much more satisfying to be a part of a team that’s doing something awesome than it is to be all on your own trying to jump up that hill and make something out of nothing,” she shared in the interview.

As part of her on-screen support in Nyad, Jodie also spent a lot of time getting to know Bonnie and her mannerisms, the athlete shared with People.

“I can’t sit still for the most part,” Bonnie told the magazine. Jodie came over. We sat outside for three hours straight. I never even thought about standing up. You know, ‘What’s your favorite food?’ ‘Oh, me too!’ That kind of thing.”

The women still stay in touch and bond over their love of the NFL and a card game called Push.