Richard Simmons Cause of Death Under Investigation

The official cause of death of celebrity fitness guru Richard Simmons is under investigation, though there is “no foul play” involved.

Richard Simmons Said "I Know People Miss Me" in Final Interview Before Death: "I Miss Them, Too"

Simmons died on Saturday . The Medical Examiner’s Office announced Monday that his cause of death has been deferred, meaning that an investigation and additional testing are needed, People reported.

Simmons rose to fame in the 1980s as a motivational speaker and weight loss instructor famous for his own health journey. He starred in his own exercise show and sold millions of aerobics Sweatin‘ to the Oldies videos and DVDs while running a Los Angeles fitness studio. He wrote several books, including Richard Simmons’ Never-Say-Diet Book from 1980, and later appeared as himself on various TV shows including Arrested Development , Amazing Stories , CHiPs , The Larry Sanders Show and General Hospital .

His public appearances greatly decreased about a decade ago, after he closed his fitness studio and ceased official engagements.

The New York Daily News reported in March 2016 that he was being held against his will in his home. But Simmons, who hadn’t been seen in public in about two years, denied that, telling the Today show, “No one is holding me in my house as a hostage.” In 2017, writer, director and podcaster Dan Taberski aimed to uncover the mystery behind the fitness mogul’s retreat from the spotlight with his podcast, Missing Richard Simmons . In January, Simmons said he didn’t approve of a forthcoming biopic of his life from that will star Pauly Shore.

Simmons’ cause of death was unknown when his death was announced. A rep for Simmons told The Hollywood Reporter that he died earlier Saturday at his home in Los Angeles.

Pauly Shore Remembers Richard Simmons: "I Hope You're at Peace and Twinkling Up in the Heavens"

His brother Lenny has since said that the news “was really a shock.”

“He wasn’t feeling really well that day, because he said he thought he’d had some food poisoning, but he was getting better and going to bed a little early,” he told Entertainment Tonight . “So we really didn’t think anything about it. We all have our bad days sometimes, you know, not feeling the best and when [Richard’s housekeeper, Teresa] called me, I was in shock. I called my wife, Kathy, and I said, ‘You need to come here. You need to hear what [Teresa’s] saying.’ And it really … my soul just [felt] sucked [out of my body].”

Two days before his death, Simmons spoke to People . “I know people miss me,” Simmons said. “And you know what? I miss them, too. But I’m able to reach them through phone calls … and through emails. And I do leave the house sometimes. But I’m in disguise.”

On the eve of his death, Simmons thanked fans on Facebook for wishing him happy birthday, on July 12. “Thank you … I never got so many messages about my birthday in my life!” he wrote. “I am sitting here writing emails. Have a most beautiful rest of your Friday.”

Richard Simmons, Celebrity Fitness Guru, Dies at 76