Pumping Iron is a 1977 docudrama about the world of bodybuilding.thumb|300px|right
The first part of the film documents the life of Mike Katz, whose being bullied in his youth for being Jewish and wearing glasses spurred him to become a pro football player. When his career with the New York Jets was ended by a leg injury, Katz became a bodybuilder. Now a father of two, Katz is preparing to compete in the Mr. Universe contest. His psychological balance is thrown off by a prank by fellow contender Ken Waller, who steals Katz's lucky shirt before the competition. Katz comes in fourth; fighting back tears, he cheerfully appraises the situation before deciding to call home and check up on his wife and children.
The film then switches focus to the rivalry between Arnold Schwarzenegger and Lou Ferringo. Schwarzenegger, a ten-year veteran of bodybuilding, has won Mr. Olympia for five consecutive years, and intends to retire after a final competition; Ferrigno is determined to be the man to finally beat Schwarzenegger. The film contrasts each man's personality, home environment, and training style: Schwarzenegger is extroverted, aggressive, and works out with other bodybuilders at Gold's Gym and Muscle Beach, whereas the quiet, reserved Ferrigno-- who went deaf after a childhood ear infection-- trains with his father in a dimly lit, private basement gym. While Ferrigno surrounds himself with his family, Schwarzenegger is accompanied wherever he goes by other bodybuilders, reporters, and beautiful women. Schwarzenegger reveals himself to be a student of psychology as well as bodybuilding, crediting meticulously crafted strategies of psychological warfare against his opponents for his numerous victories.
In between interviews and workout demonstrations with Ferrigno and Schwarzenegger, the film also briefly looks at Franco Columbo, a favorite to win first in the under-200 pound division at Mr. Olympia, and one of his competitors, Schwarzenegger's training partner, Ed Corney.
In South Africa, Schwarzenegger wages his psychological warfare on Ferrigno, befriending Ferrigno and then subtly insulting him over breakfast with his family. The strategy appears to work and Ferrigno becomes troubled. Meanwhile, Schwarzenegger attends the judging for the under 200 pound class in order to scope out who his competition will be for the overall Mr. Olympia title. In a rare moment of humility, Schwarzenegger openly admires Columbu's physique and stage presence, praising him as a positive example of a bodybuilder. Columbu places first and he moves on to compete against the winner of the over 200 pound category.
Schwarzenegger, Ferrigno, and serge Nubret prepare to go onstage and compete for the over 200 pound category; in the locker room, Schwarzenegger engages in some last-minute intimidation of Ferrigno and succeeds in weakening Ferrigno's confidence. Ferrigno is visibly shaken onstage and, as a result, ends up placing third behind Nubret and Schwarzenegger, who is declared the winner. Schwarzenegger and Columbu engage in a posedown for the title of Mr. Olympia; onstage, Schwarzenegger uses his stage presence and intimidating looks to unnerve Columbu, who falters. Schwarzenegger is declared Mr. Olympia, and in a post-victory speech announces his official retirement from professional bodybuilding.
Later, at an after party for the competitors, Schwarzenegger celebrates his victory by smoking marijuana and eating fried chicken. The competition over, he wishes Ferrigno happy birthday and leads the other competitors in singing "Happy Birthday to You" as a cake is revealed. The film ends with Schwarzenegger, Ferrigno, and Ferrigno's parents riding together to the airport.