Kelly Ripa is like a walking advertisement for exercise—she appears to be high on endorphins all the time and is fit, strong, and glowy at 45. But the media darling insists she wasn’t born athletic and hasn’t even always been active.

“That’s a myth!” she said when I relayed the perception to her at the launch party for her trainer Anna Kaiser’s big, splashy new Manhattan studio and headquarters on Broadway and 28th Street.

The studio, the third for AKT in Motion after the Upper East Side and East Hampton locations, officially opens for classes this Saturday, November 7, and the schedule includes a brand-new toning class—AKTone—that Kaiser created specifically for Ripa, when she had to give her dance cardio sneakers a rest for a minute.

“I had an injury and I couldn’t do cardio, and it was really driving me crazy…to not be able to use my body,” says Ripa, who obviously, these days, is a major wellness and fitness advocate. “Anna said ‘well, you can totally use your body.'”

After sweating my way through the muscle-quaking AKTone class with Kaiser, I caught up with Ripa to get some more surprising facts about her fitness habits.  (And no, she didn’t get the Kim Kardashian butt from AKT. I asked.) —Lisa Elaine Held

1. She started her love affair with exercise really slowly. “I didn’t really start working out until my youngest son was in nursery school, and I started really slow and really small. I started working out three days a week. And by working out, I mean I would walk on a treadmill for a half an hour, and then I started jogging, then I started running, you know, just upping my miles every week. I would try to go farther and farther.”

2. Regis was part of her inspiration to get active. “Regis Philbin was really a great exerciser. He loved to exercise, and he still does. I think he exercises every day. And he was really the one that was like, ‘You should exercise! you would love it!'”

3. After trying lots of different workouts, she’s now been working out with Anna Kaiser for eight years straight. “I broke up with all of my other mistresses, and that was it. I think the world of her. She’s really changed my body. She’s made me aware that I had a core—I didn’t know I had one.”

4. Ripa’s injury made her realize there’s more to working out than cardio. “I have to say that I expected my body to fall apart completely, but what we found was that my body got really firm and really strong. I like to focus on cardio so much…but what you don’t realize is when you’re using those large muscle groups and you’re strengthening and toning, it is cardio. I was out of breath every single time. It’s all cardio, it’s all related. You can get that sweat and you can carve out muscle doing those toning exercises.

5. She sweats for the sake of her kids, too. “I want to blueprint an active lifestyle. My kids are all active, all in sports, and I know it’s a direct result of seeing their parents exercise.”

For more information, visit aktmotion.com