At one point, Lou Ferrigno walked into Menahem Golan's office after reading the original script, which was filled with more violence and gratuitous sex, told him that the script was a "piece of shit," and threw into the garbage. Ferrigno wanted a more family-oriented fantasy film, which was finally released against Golan's wishes.
Sybil Danning had a huge crush on her musclebound on-set partner, Lou Ferrigno, although he was not interested in her, romantically (he was married). In her future interviews she would call Ferrigno a "fine specimen of masculinity." Ferrigno was in peak physical condition during the filming.
In Electric Boogaloo: The Wild, Untold Story of Cannon Films (2014), Sybil Danning said she would've preferred a more "adult" version of Hercules. She told Femme Fatales magazine that the original script was an R-rated blend of adventure and erotica, in which the lonely Hercules wanders around until he meets a power-hungry, manipulative queen who seduces him and tricks him into using his strength to conquer other kingdoms. It wraps up when she fights Hercules to the death. The original reason for doing an R-rated Hercules film was because Conan (1982) was such a huge success with blood, guts, nudity, and sex. Instead, Danning said, Lou Ferrigno and his wife, Carla, turned it into a kiddie film.
The movie was supposed to be a star vehicle for Lou Ferrigno - the same "Hercules in New York" (1969) was for Arnold Schwarzenegger. Despite being incredibly successful as a bodybuilder (as Schwarzenegger was), and despite the fact "Hercules" was a bigger box office hit than "Hercules in New York", Ferrigno never became an A-list action hero.
The scene in which Hercules battle the bear, footage was edited from the film "Grizzly" (1976).