WELLINGTON, New Zealand -- Les Mills, the New Zealand Olympian who founded the gym chain that bore his name, died Monday at age 91, his company said.

A statement posted to the website of the company Mills founded said he died “peacefully.” The statement didn’t cite a specific cause.

Leslie Roy Mills represented New Zealand at four Olympics, competing in discus and shot put, and won five Commonwealth Games medals. He was the mayor of Auckland, New Zealand’s largest city, from 1990 to 1998.

His name is best known in connection with the fitness brand he founded, beginning with the first Les Mills gym opened in Auckland in 1968. A chain of 12 gyms now operates throughout New Zealand.

Mills’ son, Phillip Mills, later launched the Les Mills International brand of step aerobics and other group fitness classes, including popular offerings such as BodyPump and BodyCombat, which are taught in more than 100 countries, according to the company’s website.

“Dad was immensely strong, driven, and always cared deeply for the less advantaged,” Phillip Mills said in a statement. “He left a lasting impression on everyone he met, and his spirit lives on in gym workouts around the world, continuing to help people fall in love with fitness.”

Mills was born in Auckland in 1934 and competed in his first athletics event, a running race at a local park, at age 11. His family’s statement said he was inspired to open a gym after an athletics scholarship took him to the United States, where he witnessed the fitness industry’s growth.

Among his international athletics victories, Mills won gold for discus throwing in the 1966 Commonwealth Games in Kingston, Jamaica. He set a New Zealand national record for shot put of 19.81 meters (65 feet) in 1967, which went unbeaten for 44 years.

After retiring from competitive athletics, Mills became a coach and administrator in sports including track and field, weightlifting and football. He was the national sports director in Papua New Guinea from 1974 to 1976, developing facilities and training staff across the Pacific country.

Mills’ wife Colleen died in 2005. He is survived by his children Phillip and Donna, daughter-in-law Jackie, grandchildren Diana, Les Jr., Gabriel and Moana, and many great-grandchildren, his family said.