Gym rats with six-pack abs, leotarded lionesses each with a toned gluteus maximus, and California's governor owe their strength and physiques, in part, to Joe Gold. The legendary bodybuilder, who founded Gold's Gym and World Gym, died July 12 at age 82 at a hospital in Marina del Ray, Calif.

No cause of death was reported, but he had been hospitalized for several days and recently had had a heart attack.

Mr. Gold, son of an East Los Angeles junk dealer, was a lifelong bodybuilder who opened the first Gold's Gym in 1965 in Venice, Calif. One of his customers was an Austrian immigrant named Arnold Schwarzenegger, whose 1977 movie "Pumping Iron," filmed at the original gym, helped popularize the sport.

Bodybuilders credit Mr. Gold with creating the gyms that became the "mecca of bodybuilding" and for designing and building the workout machines that enabled them to exercise with more than free weights.

Mr. Gold had practice for those inventions: As a teenager, he started his first "workout gym," which friends dubbed the Dugout, in an old garage in front of his parents' house. He told the Los Angeles Times in 1989 that he and his friends made weights of cement and old flywheels.

The young Mr. Gold morphed into a buff resident of Southern California's original Muscle Beach, where he traded workout tips with Vic Tanny and Jack La Lanne. A cover photo of him in Muscle Power magazine from the period shows a muscle-bound young man in leopard-spot briefs striking a classic pec-flexing pose. One of the spectators at the scene, entertainer Mae West, tapped Mr. Gold to be part of a beefy chorus line for her Las Vegas show in the 1950s.

By the mid-1960s, Mr. Gold opened his eponymous gym, welding most of the equipment himself, and allowed the young immigrant Schwarzenegger to work out free. Schwarzenegger, who used that platform to earn his title of Mr. Universe, starring roles in Hollywood movies and the governorship of California, called Mr. Gold a father figure and a friend in a statement Monday.

Mr. Gold sold the rights to the gym's name six years after its founding. The new owners turned it into a successful franchise operation with hundreds of outlets. Mr. Gold, who had served in the Merchant Marine on and off over the years, went to sea again and returned in 1977, when he opened World Gym. With Schwarzenegger's endorsement, Mr. Gold built and successfully franchised that business.

"I built a special kind of gym," he said in 1992. "I don't stand any nonsense, no fighting or arguing, and I eliminate all the frills and hype. People come here to work out. You do your thing, and then you leave."

Originally, Mr. Gold did not allow women in his gyms. He eventually reconsidered and told a reporter: "They're better members than the guys. They don't stay all day, they don't stink and they pay on time.''

He was known for nicknaming his friends -- Schwarzenegger was dubbed "Balloon Belly" because Mr. Gold didn't think his abdominal muscles were well defined. In Mr. Gold's youth, friends called him "Li'l Abner," after a cartoon character who also wore tight jeans, tight T-shirts and high-top sneakers. One of his friends also dubbed Mr. Gold "Joe," although his given name was Sidney. That nickname stuck.

During World War II, he joined the Navy and was badly injured when his ship was torpedoed at the Battle of Leyte Gulf in the Philippines. He spent six months in a Veterans Administration hospital before returning home.

For most of his life, he suffered from debilitating pain as a result of his war injuries, and many of his last years were spent in a wheelchair. He surrendered operation of World Gym to Schwarzenegger in the early 1990s when health problems forced him to stop working for a year.

He leaves no immediate survivors.

Joe Gold was a friend and mentor to Arnold Schwarzenegger.