Grant Gustin plays Barry Allen/The Flash on the CW show The Flash. He has a background in musical theater and dance but has transitioned to focusing on running and bulking up for the superhero role. He trains with a track coach to improve his running form and does full-body workouts along with pullups and pushups to look fit on the show. Gustin stays disciplined on set by eating plain, healthy meals like chicken and salads to fuel his workouts and long filming hours.