I Tried The Tone It Up Fall Challenge & I Don't Know How To Feel

If you've never heard of the Tone It Up girls, they're a pair of BFFs-turned-certified personal trainers named Karena and Katrina. With 1.2 million followers on Instagram, the TIU girls occupy a space in the pantheon of social media trainers, and they're recognized for their motivational TIU challenges, goofball attitudes, and actual mermaid hair.

Now if you are familiar with the TIU girls, then their workout challenges might strike you as surprising, given our fitness philosophy, which focuses on rational fitness (which is exactly what it sounds like). In the past, many of the TIU challenges have focused on literally whittling your body away, and participants were encouraged to measure their body parts in order to track progress — they even sell branded tape measures for this exact task! But Karena and Katrina must have caught on to the fact that when you focus on what your body can do and how you feel, rather than how you look, it's healthier and more sustainable. (And it also just makes more sense.)

Their Fall Challenge is designed to "refocus and take your results to the next level," which is a far cry from the others that promise you a slimmer, more bikini-acceptable body. Before starting, you're encouraged to journal about how you want to feel, physically and emotionally. There's one section that prompts you to write about a "physical change" you want to see, whether it's stronger arms or building muscle overall. Other than that, there's no mention of weight loss or size.

So, since I can get on board with this general philosophy, I decided to join Karena, Katrina, and their 1.2 million Instagram followers. For 21 days, I would pretend to be the third Tone It Up girl — Karena, Katrina, and Corinna (which just so happens to be my full name). Ahead, I documented how I felt on each day of the challenge, and what the workouts entailed.