I really did not want to go to Dance Church. I'd first heard about the twice-weekly dance class at Velocity Dance Center from a friend who goes to Burning Man, and while I adore this friend, we just aren't into the same things. She believes in moon ceremonies and astrology; I believe in science and eating gluten. So when she told me about how incredible Dance Church was, how it had literally changed her life, my first thought was that it sounded terrible. Dance plus church? Two nightmares for the price of one. Besides, I'd walked by Velocity after Dance Church before—I'd seen the teeming packs of hard-bodied millennials on their way out. They looked like the sort of people who drink cold-pressed juice and exercise for fun. My beverage of choice is milkshakes and my daily workout is a walk to the kitchen. I doubted I would survive a 90-minute high-intensity dance class/cult, and I did not intend to find out.

A year later, my girlfriend decided it was time to increase our life spans for some unknown reason, and she gently suggested that Dance Church was how we were going to do it. It still sounded awful, but she said it was either that or CrossFit. I agreed to go. Once.

Dance Church is led by Kate Wallich, a local choreographer who founded the class in 2010 at a now-defunct dance co-op in Pioneer Square. At first, the class was just Wallich and a few of her dancer friends getting together for a sweaty workout on Sunday mornings. She initially called it "Sunday Morning Movement Class"; it was her students who came up with the much catchier "Dance Church." And there is something vaguely religious about it—or at least as religious as a dimly lit dance studio filled with bodies writhing to Kesha and Drake can be.

After a slow start, Dance Church has blown up in the last couple of years. Now all of the proceeds go to support Wallich's nonprofit dance company, and she hopes to partner with other organizations to bring Dance Church beyond Capitol Hill. "I want to teach young and at-risk kids how to shake their bodies," she says. "I think it could make them feel empowered."

Wallich describes Dance Church as "the dance party you wish you'd had last night." I describe it as the most physically painful 90 minutes of my life. It was part free dance, part aerobics—and the congregation would have looked at home at an Opening Ceremony sample sale. Within seconds, I was slick with sweat and could feel my face turning a deep red. The studio was near black, with the mirrors covered and one light illuminating Wallich in the center of the room—a petite, blonde Richard Simmons commanding her congregation: Arm up! Arm up! Arm up! Now squat! Squat! Squat!

I should have hated this scene, but quickly something happened: I realized there was no way out. Snark and disinterest, my go-to coping mechanisms, could not save me now. All I could do was dance. And so I did. I stayed on the edges of the room with my eyes closed, feeling the beat in a way I never do at actual dance parties, where I'm far too self-conscious to let go. The crowd rolled together in a well-toned wave, and I moved in time with them. It was everything I loathe in the world—trendy, pricey, barefoot, exhausting, and overtly hip—and, somehow, I loved it.

After an hour and a half of unceasing movement, the lights—blissfully—came on. It was over. My girlfriend and I mopped our faces and gathered our things.

"What'd you think?" she asked. "Would you go back?"

"No way," I said. "That was awful. But we should probably go ahead and get punch cards. If you pay for 10 classes up front, there's a deal on cold-pressed juice."

Dance Church is at Velocity Dance Center on Sundays at 10 a.m. and Tuesdays at 8 p.m.