For me, watching Pumping Iron presented a new angle of Arnold Schwarzenegger for me that I had never really been conscious about. It was actually somewhat hard to watch the footage, knowing that this person was going to be California's governor. If I would have seen this clip beforehand, maybe I would have influenced more people to vote one direction or the other during California's gubernatorial elections.
One thing that is actually amazing about this competition that is presented in the movie is that the 'hegemonic masculine' guys presented in the documentary are judged not based on strength and how much they can lift - the classification that we always associate with masculinity. Instead, they're judged purely on looks. Schwarzenegger even summarizes that, saying that the competition judges based on muscularity, proportion, and symmetry - not on the amount one can lift.
Another peculiar characteristic about this competition is that the event is extremely erotic - all of the contestants are put on display with as little clothes as possible - in most cases, just a speedo covering up the privates. This gets even more interesting when the audience is analyzed. Who are the most enthusiastic audience members? The men. They are the loudest ones about how much they like the body builders. And the body builders enjoy it! Schwarzenegger even claims that he gets off on this process, saying "I cum all the time." So male viewers are constantly watching him cum. In this sense, the 'manliest' show is extremely homoerotic…
...Which brings me to the final point that I actually appreciate. In John Berger's Ways of Seeing, it is argued that women are always watched, and are thus objectified. In Pumping Iron, the roles are reversed - men are the ones constantly watched. In the opening scenes, the ballet dancer tells Schwarzenegger "They're not just watching you in individual poses, but also as you transition - they're constantly watching." And by constantly being watched, the men are objectified. The movie continues to drive that point home, showing male bodies without the heads, making the statement that it's the body, not the person, that's being examined. Without necessarily realizing it, these bodybuilders are entering the role that's traditionally held by women - being an object on display.