Exercise equipment has existed since China 6000 BC with martial artists using equipment called dings , as well as weighted stones. Ancient Egypt also had overhead sack swinging and Ancient India had heavy clubs they used to exercise. The ancient Greeks would use halters, precursors to dumbbells and created the first gymnasiums, coming from the word gymno, which means to train naked.
Eventually, in 1796, Francis Lowndes introduced the Gymnasticon, the first mechanical exercise machine. Later in 1885, the fitness industry began with Professor Edmond Desbonnet opening the first physical fitness center. Sig Klein and George F. Jowlett would later develop many exercise machines, such as the Jowlett Leg Press during the 1930s. Jack LaLanne and Rudy Smith would then develop the Smith Machine during the 1950s. In Harold Zinkin would later follow develop multi-stack weight machines in 1957 and “all in one” machines in the 1960s.
In the 1960s, Arthur Jones would create the Nautilus machines, which utilized chains, cams, and sprockets. The 1970s and 1980s saw the development of lines of exercise equipment, leading to fitness centers having standardized exercise equipment. This is probably why gyms have way more machines, they say free squat racks.