(Netflix Streaming, July 2017) Most documentaries come and go, sinking to the depths of popular consciousness as their topic becomes of less currency, as events overtake what it presents, as everyone moves on and often retreat in obscurity. But once in a while, lightning strikes. In Pumping Iron’s case, a look at the bodybuilding culture of the mid-seventies had the incredible luck of capturing a showdown between future-megastar Arnold Schwarzenegger, and future Incredible Hulk Lou Ferrigno. The first half of Pumping Iron introduces its subject through beige gyms and outdated clothing styles, first focusing on the rivalry between Mike Katz and Ken Waller. Documentarian George Butler is working in the prehistory of modern nonfiction movies, but his approach is very much up to the latest reality-TV standard—focusing on drama, introducing his subjects in interviews while showing them interact. After a first half that feels like an introduction, Pumping Iron goes overseas to film the 1975 Mr. Olympia contest in Peoria (South Africa), and in looking at the personalities of Ferrigno and Schwarzenegger. It helps that even at that time, Schwarzenegger is a magnetic presence: flirting, charming, but also capable of playing pranks and demolishing an opponent’s morale. Schwarzenegger, portrayed as a charming villain, overtly discusses how bodybuilding is as mental as it is physical, and how he is willing to use underhanded means in the name of competition. If Pumping Iron remains interesting today, it’s not solely because of its good overview of the then-marginal bodybuilding subculture. It’s not simply because it presents a decent pair of rivalries between bodybuilders. It’s squarely because Schwarzenegger faces off with Ferrigno, and Schwarzenegger wins. But that’s fair—George Butler got lucky, and the only thing to do when you get lucky is to enjoy it.