These films are what many film scholars will refer to as “hardbody films”—films that showcase a muscular, almost super-human male physique—and, indeed, they were ubiquitous in the 1980s.

These hardbody films followed a lot of narrative conventions that had been put in place by 1970s action films, whether cop films like Dirty Harry, military films like The Dirty Dozen, or vigilante films like Death Wish, so the generic formula wasn't entirely new. However the shift to these musclebound heroes—and the visual attention given to those muscles—resulted from several different areas of popular culture that were putting new emphasis on muscular bodies in the 1970s and '80s.

The most prominent of these influences was the increased popularity of bodybuilding and bodybuilding competitions. Bodybuilding began to rise in popularity during the 1950s and ‘60s, alongside a more general health and fitness movement, however it was very much a niche interest at that time, and didn’t yet offer the excessively spectacular bodies that we see later on. But bodybuilding gains a lot more public awareness in the 1970s. Between the original Gold’s Gym and the bodybuilding pen at "Muscle Beach", Venice Beach in Los Angeles had become a sort of Mecca for bodybuilders by the 1970s. Bodybuilding competitions also begin to gain attention during this period; for instance, the Mr. Olympia competition begins in 1965, which eventually becomes the most prestigious bodybuilding title.

At the same time, we see the rise of anabolic steroids. This is when bodybuilding shifts from the paragons of fitness that we saw in the ‘50s, like Jack Lalanne and Steve Reeves, to the “mass monsters” that start appearing in the late-’60s—Arnold Schwarzenegger, Franco Columbu, and Lou Ferrigno were the most famous of these. And those figures gain nationwide fame with the 1977 docudrama Pumping Iron, which focused on the competition between Schwarzenegger and Ferrigno for the 1975 Mr. Universe and Mr. Olympia competitions.

Notably, Schwarzenegger is the villain in that film—he’s the unstoppable beast that keeps winning, and who manipulates his competitors, and Ferrigno is the underdog that the audience roots for, yet Schwarzenegger would ultimately become the superstar that emerges from it. Lou Ferrigno was cast in the Incredible Hulk TV series shortly after Pumping Iron’s success, but Schwarzenegger would have his breakthrough in 1982, with Conan the Barbarian.

But bodybuilding isn't the only place that muscular men are being featured in American pop culture of the '70s. While all of this was happening in bodybuilding, the Golden Age of Boxing begins in 1971, when Muhammed Ali returned to boxing after having been exiled for his refusal to serve in Vietnam. His 1971 fight against Joe Frazier was dubbed the “Fight of the Century” because both had legitimate claims as the undefeated heavyweight champion, and it received enormous attention. This catapulted the sport's popularity, and Frazier, Ali, and George Foreman kept boxing in the public eye, in part because they offered such distinctive characters. So this was another place where we saw muscular behemoths on display, and the movie Rocky would exploit that in 1976, launching Stallone’s stardom.

The Golden Age of Wrestling would begin in the 1980s, when Vince McMahon begins his campaign to make the World Wrestling Federation the premier wrestling promoter in the country. Prior to this, wrestling was divided among various territories around the country, and there wasn’t a singular unifying organization for the “sport”—when Vince McMahon successfully began syndicating the WWF on television, he turned professional wrestling into a televised national entertainment rather than a live regional one, and the success of the WWF (later known as WWE) further places musclebound bodies in the spotlight.

Simultaneous to all this, we also see the explosion of martial arts films, originally from Hong Kong. These bodies weren't the hulking behemoths of bodybuilding, boxing, or wrestling, however they were still strong, hyper-fit men who displayed their muscles and performed violence with their shirts off.

Bruce Lee became a worldwide celebrity in the early 1970s, and even after his death in 1973, kung fu films continued to be successfully imported into the US, and a variety of low-budget American filmmakers continued to make martial arts exploitation films throughout the ‘70s. And these were also a manner of film that frequently involved muscular men fighting shirtless. The major studios didn’t have much interest in martial arts at that time, however various American independents had success with such films during the ’70s.

Among the bigger American stars was Chuck Norris, who had his first significant role as a villain in Bruce Lee’s Way of the Dragon in 1972, and another as the primary villain in a 1974 film. But his breakthrough was in a 1978 thriller, Good Guys Wear Black—an independent film that couldn’t get distribution, so the filmmakers decided to four-wall it (which meant renting the theaters themselves), and it eventually made $18 million on a $1 million budget. After that, Chuck Norris would star in 14 films over the next 10 years. And elaborate, choreographed hand-to-hand combat would become a staple of ‘80s action films as well.

So between bodybuilding, boxing, wrestling, and martial arts films, we see a new emphasis on muscular male bodies in several different areas of popular culture as we enter into the 1980s, all of which combine to influence '80s hardbody action cinema.

1982 would be a pivotal year for this type of film:

• After a series of supporting roles, Arnold Schwarzenegger rose to stardom with Conan the Barbarian in 1982, which was a big hit.
• Stallone successfully moved beyond his role as Rocky with First Blood, the first Rambo movie, in 1982, which was also a hit.
• And Hulk Hogan and Mr. T got their first national fame with supporting roles in Rocky 3, also in 1982.

Pretty soon, Schwarzenegger and Stallone became two of the biggest movie stars on earth, and Hollywood began searching for other musclebound talent (some of which would come out of wrestling, like Roddy Piper and Jesse Ventura).

If you're interested in reading up on these films and their history, Susan Jeffords' Hard Bodies: Hollywood Masculinity in the Reagan Era (1993) is the most prominent book on the subject.