Eternally upbeat fitness guru Richard Simmons doesn't have a bad word to say about anybody--even when they deserve it.
In a new interview with Men's Health, the aerobics icon opens up about his speaking engagements over the years, including his "many" appearances on the Late Show with David Letterman.
"I love David. He's more complicated than any of them, that David," Simmons shares. "You know, I've never actually met him? . . . 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."
After years of being ignored, Simmons says he's not so sure he'd want to sign on for another guest gig alongside the late night host.
"Maybe one day, when the time and everything is right. Because I do love him," the fitness icon muses. "The last time I was on, we went to commercial and I was like, 'I'd love to meet your wife!' He was like, 'You never will.' And then I was like, 'And see your son!' And he was like, 'You'll never see him.' And then we come back from the commercial and he's all friendly with me again."
Adds Simmons, "You think I'm kidding, but I'm not making this up."
Simmons also shares his thoughts on fitness-focused reality shows, a la The Biggest Loser.
"I'm not into any show that makes people compete when they lose weight," Simmons--who has spoken candidly about his struggles to get healthy--says. "I think the show has some merit. . . But voting off people every week because they didn't lose enough weight. . . That's terrible. Who are you competing against? It's you."
Simmons says he isn't going to let any negativity--from peers, or the media more generally--get him down. The 63-year-old workout enthusiast still teaches "a full hour-and-twenty-five-minute class," three days a week--and says he has no intention of slowing down.
"I wouldn't be able to sit still," Simmons tells the mag about possible retirement plans. "If I have to die, I want to combust in the middle of one of my classes."
This article originally appeared on Usmagazine.com: Richard Simmons: David Letterman is "Very Standoffish"