Nyad details the extraordinary journey of legendary swimmer Diana Nyad who became the first person ever to swim from Cuba to Florida, achieving her goal after four attempts at the age of 64.

Veteran documentary filmmakers Jimmy Chin and Elizabeth Chai Vasarhelyi make their first voyage into narrative storytelling with this star-studded Netflix blockbuster, so it shouldn’t be too surprising how little of the movie is Hollywood magic.

Speaking to Daily Express US at the London Film Festival, Elizabeth revealed that while there are still some “smoke and mirrors”, its leading stars Annette Bening and Jodie Foster did much of the heavy lifting.

She admitted with a chuckle: “They are not that tan.

“They had a lot of spray tans and apparently when you have that many spray tans you make your sheets entirely brown and this happened every week.

Netflix’s new movie highlights the incredible feats of Diana Nyad (Image: NETFLIX)

Elizabeth revealed they tried to stay as true to Diana’s story as possible during filming (Image: NETFLIX)

“But it was really important for us, Annette and Jodie to show women in their full beauty and complexity who aren’t beautiful in conventional terms.

“Like (Jodie’s) six-pack is real! Those abs are real, and that’s just a testament to her performance.”

Annette, who portrays the titular swimmer, Diana Nyad, also put in a hefty amount of work, training for a full year before ever walking onto the set in hopes of doing justice to the sensational true story.

In the movie, Jodie portrays Diana’s best friend and coach Bonnie Stoll who also strutted the red carpet at the film festival and couldn’t stop gushing over the Silence of the Lamb star.