Actors Who Went Through Extreme Body Transformation For a Role

J.K. Simmons, Justice League

J.K. Simmons seriously underwent a shred in order to play Commissioner Gordon in Justice League. Aside from a tremendous amount of dedication to his regimen, Simmons credits part of his success to his trainer Aaron Williamson. An ex-Marine, Williamson's been providing elite-level training—morphing Hollywood A-listers into bona fide muscleheads like he's cranking out action figures on an assembly line—to the likes of Zac Efron, Dwayne Johnson, Jamie Foxx, and Jai Courtney. He first got his hands on Simmons in 2015 to help him shape up for Terminator Genisys.