While doing my indoor exercise routine yesterday morning -- my outdoor running and walking is on hiatus while my shin splints heal -- I tuned in to a little Live with Regis & Kelly. Survivor host Jeff Probst was sitting in for Regis, and he and Kelly happily welcomed Janet Jackson for her very fist visit to the show. The spunky threesome talked about Jackson's new movie -- Why Did I Get Married? -- and her new diet and weight loss book. They even discussed a little fitness trivia.

Ripa was thrilled to announce this fitness flash: Rhythm Nation, one of Jackson's smash hits, is reportedly the most listened-to song by those who rock while working out. This information comes courtesy of Fitness Magazine, said Ripa, who happens to have this very song on her iPod. When no one is watching her on the treadmill, she told her audience, she breaks into a total Rhythm Nation dance routine. On the treadmill? Yep, that's what she said.

What's your favorite workout song? And tell us -- do you bust a few moves when no one is looking?