The worst kept secret in the world behind the making of Captain Marvel was that Brie Larson got in crazy great shape to play the titular hero. Fully committing to the part, she trained excessively for months, and did everything she could to enhance the realism of her performance and her character's incredible strength.
During this time, Brie Larson regularly updated fans with her progress on social media, posting about her various feats and milestones - and the fact that she continues to upload videos from her workout sessions basically suggests that where her training for Captain Marvel ended, her training for Captain Marvel 2 began:
As Marvel Cinematic Universe fans know, we are still at least a few years away from the release of a direct sequel to Captain Marvel, as that particular project isn't a part of the announced plans for the 2020-2021 period that has been dubbed Phase 4. That being said, exercising is a lot easier when you are doing it consistently and not taking long vacations from it, so there is a lot of logic in Brie Larson continuing to try and get stronger and stronger while her solo movie follow-up awaits a release date announcement.
Watching the Oscar-winning actress repeatedly lift her own body weight simply from the strength of her grip is seriously impressive, but the reality is that all of Larson's workout videos are pretty jaw dropping. Back in January she put up a post where she repeatedly raised a 275 lbs barbell off of her hips, and followers won't soon forget about the time when she literally pushed a 5,000 lbs Jeep:
Perhaps the best part of all of this, though, is that all of this training began because of a misunderstanding on Brie Larson's part. Speaking with reporters during an on-set interview while Captain Marvel was in production, the actress explained that it wasn't until the start of principal photography that she realized she didn't actually need to get as fit as she did for her performance:
It wasn't until we started shooting, and I started doing all my own wire work stunts, and flips and stuff that people were like, 'You know nobody, now we'll tell you, nobody actually does this. We just didn't want you to stop. But now that you've kind of accomplished this thing, we don't normally do this.' And I was like, 'Huh?' But I love it.
Right now we don't know exactly when Captain Marvel 2 will start coming together (perhaps 2022?), but it's also worth noting that there definitely exists the possibility that we will get to see Carol Danvers again in a project other than her next solo film. For example, Marvel Studios has officially announced that they are developing a Ms. Marvel series for the Disney+ streaming service, and it's entirely reasonable to think that Brie Larson will at the very least cameo in an episode.