I am not sure. I know that Jack LaLane (not sure on the spelling) opened a fitness club type gym in the late 1930s or 1940s. He had a television show that was aimed at “housewives” in the sixties. My mother used to exercise along with the show when I was a kid. And there were lots of bodybuilding gyms throughout the country in the 50s and 60s. In the late 70s (1977 I think) the ACSM had a conference in Wisconsin at one of the University of Wisconsin campuses, I can’t remember now which one. I think it was La Crosse. They were certifying “exercise technicians” back then and I was too young to participate in the program.