Kourtney Kardashian Used to Do Back-to-Back Billy Blanks Workouts with Kim: ‘We Were Obsessed!’

Dimitrios Kambouris/Getty Kim and Kourtney Kardashian

Kourtney Kardashian may be known as the most wellness-oriented of the famous sisters now, but growing up she "didn't know anything really about health or wellness."

The reality star, 42, told model Miranda Kerr in a new video for Vogue Paris that she felt clueless about that world as a teenager, though she was starting to exercise with sister Kim Kardashian West.

"I did work out, starting like, in high school," Kardashian said. "Kim and I used to work out."

Kerr asked Kardashian what workouts she would do, and the mom of three starts gushing about Billy Blanks' Tae Bo classes.

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"Oh my god we were obsessed!" Kardashian said.

"I did the DVDs!" Kerr said. "I made my grandma do one with me."

"No way!" Kardashian replied. "It's the best workout. Especially for like, your obliques and your abs. and we would do back-to-back classes, like two classes in a row."

Kardashian said that along with taking Billy Blanks classes, she would try to eat healthy foods, but "I just didn't really know what it meant."

"I just remember so many trends, like Atkins diet and so many different things," she said.

Now a founder of the lifestyle website Poosh, Kardashian has figured out what works best for her body, and primarily follows a vegan diet.

"When I had Mason, I remember Nicole Richie was like, 'You have to read this book,' it's called Super Baby Food," she said. "So like, when I read that, it was all about like organic fruits and vegetables and really giving them like, no processed foods and everything from the earth."

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"It kind of like, snowballed, and I think my journey was so much a part of our show, from me learning about organic stuff," she continued. "I used to go to my sisters' refrigerators and clean them out, and everyone thought I was crazy. And I would clean out the pantries because none of us grew up that way."

Now vegan diets are more mainstream, though Kardashian isn't sure what motivated her to start following one in the first place.

"I just decided to do it," she said, adding, "It's definitely better for our planet."