The MCU is a coveted league to be a part of by now, but that doesn't mean it's easy. Many of the actors have to go through intense physical transformations to look the part of the heroes they play. Basically, there are more muscles in the MCU than the WWE, so let's see how these folks looked before and after joining Marvel.

1. Kumail Nanjiani's transformation for Marvel's Eternals became a viral sensation.

2. Chris Evans had to go beast mode for his role as Captain America.

3. Chris Pratt went from lovable goofball in Parks and Recreation to ripped lovable goofball in the MCU.

4. Chris Hemsworth definitely did justice to Thor.

5. Michael B. Jordan's transformation has been one for the ages.

6. Paul Rudd also joined the 6-pack train.

7. Brie Larson's workout regime for Captain Marvel was all over social media.

8. Jeremy Renner truly mastered the transition from emo to badass.

9. Robert Downey Jr. was always a gangster. But after joining the MCU he became a gangster with muscles. 

10. Tom Holland also has a six-pack. Freakin' everyone in the MCU has a six-pack! 

They might look good, but they all probably had to give up on burgers. That's the price of being a hero!