Superman doesn’t necessarily need to prove he’s Superman to get big.
From https://www.menshealth.com/fitness/a28074329/henry-cavill-arms-biceps-workout/
from
https://healthnews010.wordpress.com/2019/06/18/henry-cavill-reveals-his-secret-to-getting-big-arms/
From https://jamesjohnson10.blogspot.com/2019/06/henry-cavill-reveals-his-secret-to.html
James Johnson 