Before playing Black Widow, I had never been inside a gym...Scarlett Johansson

Scarlett Johansson, who plays Black Widow in Iron Man 2, talks about the most difficult obstacle she faced while filming the sequel. Johansson first appeared in the Marvel Cinematic Universe as Black Widow in Iron Man 2, which followed Tony Stark as he battled both his deteriorating health and a vengeful madman.

Since her debut in Iron Man 2, Johansson has appeared in nine MCU films, including the world-record-breaking features The Avengers and Avengers: Endgame, as well as her own standalone film, Black Widow. In the wider MCU storey, both Johansson and Black Widow have gone through a lot, including an implied romance with the Hulk and countless brutal fighting sequences.

In a recent interview with Vanity Fair, Johansson stated that the most difficult aspect of filming Iron Man 2 was having to prepare for heavy stunt work for the first time.

Scarlett was just in her early twenties when she was cast as Black Widow, and she claims she had "never stepped foot in a gym" before being cast. "That was a tremendous event for me since I was, I don't know, 23 or 24 when I was cast in Iron Man 2," she told Screenrant. I'd never been to a gym before, and I only had five weeks to prepare for these massive stunt scenes.

It was before we figured out how to be most efficient in the process of shooting stunt work—what could be handed off to other stunt guys and what the actor would actually need to know—when we were doing it over a decade ago."

Given Johansson's shenanigans throughout her time in the MCU, this comes as no surprise. If she wasn't physically prepared for the activity needed of Black Widow, it would be difficult for her to retain her mental health. Johansson's efforts have definitely paid off, as the ex-assassin has gone from a supporting role in Iron Man 2 to a fan favourite in one of the world's most successful franchises.