Corenswet's physical trainer breaks down the routine that helped the formerly svelte actor put on 40 pounds of muscle—and how he got Nicholas Hoult prepped for Lex Luthor.

The new Superman, David Corenswet, has been intensely training to meet the physical demands of the role. Celebrity trainer Paolo Mascitti shares insights into Corenswet's customized workout regimen, highlighting exercises and techniques used to build muscle and tone his physique for the character.

Corenswet prepares to leave his relative anonymity behind as he steps into the red boots of the most popular superhero of all time.