After a 1972 photo assignment to cover the Mr. Universe Championship for Life magazine, George Butler wanted to make a documentary about what he’d experienced. It took forever to convince investors to come on board, because who wanted to watch muscleheads pose and listen to a heavily accented man speak?

The original plan was to take actor Bud Cort and have Arnold Schwarzenegger train him, but it just didn’t work. Instead, the documentary started to focus on the bodybuilders — who at that time were seen as a freak sow — training at Gold’s Gym.

Like all documentaries, an angle was decided on: Schwarzenegger would become the charismatic villain and Lou Ferrigno the underdog trying to beat him. The problem is, Arnold ends up being so likable, no matter what he said, that people ended up loving him. Well, it’s not really a problem per se…

Anyways, the other battle was between Mike Katz and Ken Waller, lifelong friends who were simply pranking one another. Waller stealing Katz’s shirt ended up getting him booed at contests for the rest of his life.

After finishing the Mr. Olympia contest, the film was in development hell for two years. To raise funds, Butler had Butler an exhibit at the Whitney Museum of American Art in New York City where the bodybuilders — including Arnold — acted as living sculptures. This got the movie made.

The film follows the lives and workout routines of these bodybuilders. Its main narrative is the difference between Arnold and Lou: Schwarzenegger works out in public at Gold’s Gym and Muscle Beach while Ferrigno trains with his father in a dark basement. Arnold is always with women, Lou is with his family. Arnold brags non-stop; Lou is quiet and reserved. Arnold uses psychological warfare while Lou just believes in hard work.

We also meet Arnold’s training partner Franco Columbu and see several of the other competitions within Mr. Universe, as well as Arnold outright mentally terrorizing Lou during a friendly breakfast and backstage. And you know, we should be kind to everyone and not be bullies but damn it if I don’t love Arnold the most of any actor and would let him punch me repeatedly in the stomach if he asked. He wouldn’t even have to ask nicely.

Co-directed with Robert Fiore, Butler’s co-writer Charles Gaines — also the narrator of the film —  wrote the book where Pumping Iron gets its name. A writer of outdoor sports, an active believer in the conservation movement and the inventor of paintball, Gaines has led a fascinating life.

The movie that pretty much cemented the fact that Arnold was going to one day rule Hollywood — even if he made up the story about skipping his father’s funeral — this movie remains quotable and always because of Arnold: “Can you believe how much I am in heaven? I am getting the feeling of coming in a gym, I’m getting the feeling of coming at home, I’m getting the feeling of coming backstage when I pump up, when I pose in front of 5,000 people, I get the same feeling, so I am coming day and night. I mean, it’s terrific. Right? So you know, I am in heaven.”

The film ends with Arnold smoking a joint and eating fried chicken after winning Mr. Olympia. Does it get any better than that without crushing your enemies, seeing them driven before you, and hearing the lamentations of their women?

One more line from Arnold: “Milk is for babies. When you grow up you have to drink beer.”