Simmons - who first appeared on The Howard Stern Show in the 1980s - explained Men's Health why his interviews with Stern are often emotionally charged.
"Those are real [tears]! I'm not going to lie to you. I use at least a half-box of Kleenex when I talk to Howard," the fitness guru admitted. "I've known him for so long, and sometimes he asks me things... he just hits me for a loop. I can't believe some of the things he asks."
He also said of Stern's hard-hitting questions: "I've been doing his show for 22 years. I've always loved him, but he just likes to rile me up. I'm just an emotional kind of person. I sit there and bawl."
Simmons also recently spoke about his complicated relationship with David Letterman, who he has also frequently clashed with in television interviews.
"I love David. He's more complicated than any of them, that David... You know, I've never actually met him?" Simmons claimed.
"You do the show with him, and when they go to commercial, they remove you. You're just not allowed to talk to him. Or if you are, he's very standoffish."
Simmons most recently appeared on David Letterman's chatshow in 2008.
Listen to Richard Simmons's 2012 Howard Stern Show interview below (warning - mature content):