Natalie Portman's muscular appearance in Thor: Love and Thunder has become a major talking point among fans, with many blown away by her bulked-up transformation.
The Oscar-winning actress typically sports a much slender physique, so it's not surprising she underwent some grueling gym sessions with her personal trainer, Naomi Pendergast, who helped turn Natalie into her superhero alter-ego, The Mighty Thor.
WATCH: Natalie Portman's changing appearance throughout the years
Naomi has now revealed exactly how Natalie achieved her new look – particularly her sculpted arms – and it's not for the faint-hearted.
Speaking to US Weekly, Naomi – who is the director of RPX Fitness – revealed that Natalie began training for the role four months before filming started and worked out five days a week for 90 minutes to two hours for ten months.
"Natalie did five sessions a week and did not miss one session for the whole time period we trained," Naomi said, adding that the main goal was to bulk up the actress's arms and abdominal muscles.
Natalie showed off extremely defined arm muscles in Thor: Love and Thunder
"We also worked on stability and agility for injury prevention as Natalie had some dynamic stunt scenes that required her to move, twist, and land in various positions," she added. "I was also really pleased she got through the challenging stunt process without any injuries."
To achieve the desired results, Natalie's workouts included boxing, skipping, core work, and weightlifting. She also dramatically altered her vegan diet and increased her protein intake to build and maintain her muscles.
Natalie's typical diet while filming consisted of oats and berries for breakfast, vegan falafels for lunch, and vegan curry for dinner, with each meal accompanied by a protein shake. Snacks included fruits, nuts, and salads.
Natalie appears to have scaled back her training since filming wrapped
"This amount of food was obviously way more than Natalie normally eats," Naomi explained, adding: "But it was essential for her to maintain this throughout filming to keep the muscle she had developed."
Natalie recently spoke of her new muscular figure, telling Variety: "On Black Swan, I was asked to get as small as possible. [For Thor] I was asked to get as big as possible.
"That's an amazing challenge – and also state of mind as a woman. To have this reaction and be seen as big, you realize, 'Oh, this must be so different, to walk through the world like this.'"
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