Brie Larson ''sacrificed'' for her role in 'Captain Marvel'.

The 29-year-old actress stars as the titular character in the upcoming Marvel movie and her co-star Samuel L. Jackson - who reprises his role as Nick Fury - says her workouts to prepare for the movie were ''insane''.

Speaking to The Hollywood Reporter about workout videos of herself that Brie showed him, Samuel, 70, said: ''I was, like, 'She's insane! What are you doing? Are you pushing a car up a hill? What the hell? What's going on?' She sacrificed.''

He also revealed that the friendship between their characters is a huge factor in the movie.

He said: ''We're strangers when you meet us [in 'Captain Marvel']. But the creation of our relationship in that movie is very genuine and very honest so that by the end of it, you really think these two people care about each other.''

Meanwhile, Brie previously revealed she did ''nine months'' of training for 'Captain Marvel', followed by three months of stunt training for two hours every day.

She said: ''I did nine months of just training, training, and three months of stunt training with the stunt team where we spent two hours every day, five days a week. It wasn't until we started shooting and I started doing all my own wirework, stunts and flips and stuff that people were like, 'You know, nobody... now we'll tell you; nobody actually does this.' I was like, 'Huh.' But I love it. It definitely makes things more complicated in certain ways because I can be taking a lot more naps than I am.''

'Captain Marvel' is set for release in March 2019.