How the tone it up girls' Karena Dawn and Katrina Scott became the O.G. Fitness influencers

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You could consider these two Ks the OG fitfluencers. Karena Dawn and Katrina Scott uploaded their first workout video as the Tone It Up duo on YouTube in March 2009—a time when Instagram was barely in utero and a clever li'l linguist had yet to marry fit and influencer.

Their unique niche quickly caught notice. After all, the fitness media landscape at the time was ruled by mega-franchises, most of which were uberserious and focused on hardcore programs with extreme results (think The Biggest Loser). "That's just not who we were," says Karena, 36. "When we worked out, we laughed, we fumbled, we joked; we made it a date, we'd go grab a glass of wine after class. It was fun. It was a lifestyle."

How did it all start? New Hampshire-born Katrina, who had once been the heaviest girl in junior high, got hooked on fitness in high school and went to college for health science and nutrition.

Karena grew up in Indiana running half-marathons with her dad and watching her mom sweat to Jane Fonda VHS tapes.

The two crossed paths in California at an Equinox in Manhattan Beach in 2008. Katrina had just moved there with her boyfriend and was feeling pretty lost in her new habitat.

That's when she spotted Karena, a fitness model and certified trainer. "I was teaching group fitness classes on Friday nights, and I noticed this hot girl sitting on a bike," Katrina recalls. "I was pretending to pick her out to train her, but I really was just looking for a friend."

She found not only a friend but a business partner, and together they have created a brand that has morphed into an empire — DVDs, retreats, even a Bravo TV show in 2014.

While Tone It Up has grown, one thing that hasn't changed is, well, their tone: "We speak to our community how we want to be spoken to: girlfriend to girlfriend," Katrina, 35, says. Adds Karena, "You'll never see us post anything negative, because it's all about spreading positivity."

This article originally appeared in the March 2018 issue of Women's Health. For more great advice, pick up a copy of the issue on newsstands now!