Chris Hemsworth is working out to transform himself for Thor 4 beginning shortly, Hemsworth teased his transformation by showing off some of his workout regime on social media. While the actor has never exactly been in bad shape physically, he nonetheless caught attention for the image, in particular for how big his biceps are.
The sight of a ridiculously ripped Hemsworth is a stark contrast to the one fans saw in Avengers: Endgame, where the actor donned a specially designed suit to turn him into the so-called Fat Thor. With a marked change in both appearance and persona following his failure to stop Thanos, Fat Thor proved divisive over whether or not it was offensive and insensitive, with suggestions of body shaming, though Hemsworth himself seemed to delight in showing off a new side to the character. There's been some question about whether or not Far Thor would return in Love and Thunder and, while not confirmed, the workout picture suggests that Odinson will be getting back into his old shape (and then some) in the movie.
While Hemsworth's Thor 4 transformation may hint at the end for Fat Thor, that doesn't necessarily mean the MCU is completely ditching the character from the movie. Although it might seem like a betrayal of the PTSD arc in Endgame if Thor were to turn up in Love and Thunder looking like he does in Hemsworth's image, it is possible to work the change into the narrative itself, showing just how much Thor continues to grow. If Thor: Love and Thunder begins with Fat Thor, picking up where Endgame left off as he continues to find his new sense of self, then it can still have him be happy and free of the guilt and shame he felt previously while also pushing forward in new ways.
Thor's workout can tie into who he is now: in past MCU movies, Thor's greatest weakness was his arrogance. Thor always believed he was the strongest, most powerful Avenger, which is why the worst thing that could happen to him following his greatest failure was to seemingly lose that (in his eyes) by becoming Fat Thor. He never had to put the work in previously, but now he needs to. That can be what drives his body transformation in Thor4 - not because being Ripped Thor is better than being Fat Thor but because, shorn of his arrogance of old, he now has to work harder than ever before, physically, mentally, and emotionally because he knows he can't take anything for granted.
This is ultimately the pay-off of Fat Thor in Endgame. The character's appearance that way was never about being "fat", and nor was it just a joke either, but it was all about Thor dealing with his PTSD and realizing that what he previously perceived as strength was also his weakness. If Thor: Love and Thunder begins the movie with Fat Thor - which Hemsworth's workout doesn't preclude, since it was a suit anyway - and then has him needing to train to become even stronger than before rather than taking his being the God of Thunder as a given (especially with a new Female Thor on the horizon), it can properly end that part of his story and chart a new chapter for him in the MCU.
