He celebrated his birthday on Friday.
Eccentric fitness guru Richard Simmons, known for his tireless positivity, has died, his spokesman said.
Simmons celebrated his 76th birthday on Friday.
Los Angeles police responded to a 911 call from his housekeeper and found Simmons dead, police sources said. He appeared to have died of natural causes and no foul play is suspected, the sources said.
Simmons had terrified fans just three months ago when he posted on Facebook that he was dying. In March, he wrote: “I have news for you. Please don’t be sad. I am… dying. Oh, I can see your faces now. The truth is, we are all dying. Every day we live, we are closer to our death.”
He later clarified that he was not actually dying, but that the message was meant to encourage everyone to “embrace every day we have.”
Simmons has been somewhat out of the public eye lately, although there were reports earlier this year of a biopic about the fitness fanatic. Simmons criticized the reports, writing, “Don’t believe everything you read. I don’t have a manager anymore, I don’t have a publicist anymore. I’m just trying to live a quiet life and be peaceful.”
Simmons posted extensively on social media, often multiple times a day. He posted about his birthday on Facebook the day before his death, writing, “Thank you… I’ve never had so many birthday messages in my life! I’m sitting here writing emails. Have a wonderful rest of your Friday.”
In March, he told his fans that the skin cancer on his face had been removed, but that he was now doing well.
“I know some of you reading this have had cancer or know someone in your life who has had cancer,” he wrote. “Promise me you will go to your doctor and get a full checkup.”
He was born Milton Teagle Simmons on July 12, 1948, in New Orleans, but adopted the name Richard during his childhood.
Simmons has often spoken about being overweight as a child, which led him to lose weight and pursue a career in fitness beginning in the 1970s and 1980s. His first foray into weight loss came with the opening of his gym, Slimmons, in Beverly Hills, California.
In 1980, he published his first book, “Never Say Diet.” The book was the first of twelve books he would publish during his career.
His fitness videos exploded in popularity in the 1980s, along with a nationwide fitness craze that included a growing popularity of aerobics and Jazzercise. His videos, including the “Sweatin’ to the Oldies” series, became some of the most popular videos of the era.
Simmons also appeared regularly on television, including as a regular guest on talk shows such as the “Late Show with David Letterman” and the “Rosie O’Donnell Show.” He also had a regular role on the soap opera “General Hospital” and guested as himself on shows such as “Arrested Development” and “The Larry Sanders Show.”
From 1980 to 1984, he also hosted his own talk and fitness program, “The Richard Simmons Show”.
ABC News’ Bonnie McLean contributed to this report.