Who starred in the 1977 American sports documentary drama "Pumping Iron"?

"Pumping Iron" is a 1977 American docudrama about the world of professional bodybuilding, with a focus on the 1975 IFBB Mr. Universe and 1975 Mr. Olympia competitions. Directed by George Butler and Robert Fiore and edited by Geof Bartz and Larry Silk, it is inspired by a book of the same name by Butler and Charles Gaines, and nominally centers on the competition between Arnold Schwarzenegger and one of his primary competitors for the title of Mr. Olympia, Lou Ferrigno.

Shot during the 100 days leading up to the Mr. Universe and Mr. Olympia competitions and during the competitions themselves, the filmmakers ran out of funds to finish production and it stalled for two years. Ultimately, Schwarzenegger and other bodybuilders featured in the film helped raise funds to complete production, and it was released in 1977.

The film became a box office success, making Schwarzenegger a household name. The film also served to popularize the culture of bodybuilding, which was somewhat niche at the time, and helped inspire the fitness craze of the 1980s.