In order to compensate for the loss of Cort's narrative arc, Butler decided to capitalize on Schwarzenegger and Ferrigno's contrasting personalities and cast the film as the story of a heroic but "sinister" underdog (Ferrigno) against a charismatic, powerful "villain" (Schwarzenegger). To this end, Butler intentionally avoided filming Ferrigno's training sequences with bright lighting and emphasized the open-air atmosphere of Gold's Gym and the sunlight at Muscle Beach for Schwarzenegger's training sequences. Schwarzenegger claims to have helped Butler in casting himself as a villain, citing his story about not returning home for his father's funeral as having been told to him by a French bodybuilder; however, following the film's release, claims surfaced that Schwarzenegger had in fact refused to attend the funeral. Butler additionally cast the relationship between Mike Katz and Ken Waller as a sinister rivalry, filming the "football scene" where Waller decides to steal Katz's shirt after the fact in order to fill in a narrative gap. Waller and Katz were in fact close friends, and Waller's theft of the shirt was simply a spur-of-the-moment prank not intended to upset Katz to the extent that it did. Waller was later regretful of the football sequence, claiming that audiences at bodybuilding competitions continued to boo him for years after the film's release.