And the fastest growing fitness trend is…

If you trotted it out during a treadmill class at any point during 2018, congratulations: You were part of the year’s fastest growing trend in fitness.

According to ClassPass‘s recently released year-end data from 2018, there was an 82 percent increase in classes that incorporate treadmills in the past year, and they don’t expect to see those numbers slowing down any time soon. “Treadmill classes” can be exclusively running-based, a la Mile High Run Club, but can also incorporate running as a component of a more varied workout, the way Barry’s Bootcamp does with it’ half-floor, half-tread format.

“As studio fitness continues to rise year after year, it’s not surprising that we’re seeing more classes incorporating treadmills,” says Shari Castelli, Director of Empowerment Funding and Expansion at ClassPass, who also points to new treadmill technology as one of the reasons why they’re becoming increasingly in-demand among class goers. “Running has always been a popular form of exercise and combining that with the same team atmosphere, awesome playlists and motivating instructors we love in cycling and HIIT classes, has made running inside more appealing than ever.”

For its part, Equinox has seemed to take notice of the “running revolution,” as they call it. The fitness chain recently announced that they would be launching stand-alone Precision Running Labs, aka studios that will exclusively offer the Precision Running classes that have become so popular in its gyms. The first locations are open now in Santa Monica, California, and Chestnut Hill, Massachusetts, with more expected to come later this year.

So what do the people who are actually attending these types of classes have to say about them? To find out, I asked Well + Good’s Beauty and Fitness Editor—and die-hard treadmill devotee—Rachel Lapidos why she loves treadmill runs so much. “I love running but I’m not a fan of doing it outside—the treadmill is softer on my joints but more importantly I can control my speed,” she explains, while also calling the treadmill the “love of her life.” “I can see how I’m getting stronger or faster by what speeds I run at and the speeds I can sustain myself on.”

That’s not all, though: Boxing is also fighting its way to the top of the “trendy” list of late. Classpass found that the total number of boxing classes available in their network grew significantly in 2018, with both kickboxing and cardio boxing moving up in the ranks. And one other thing? Classes are apparently getting shorter. More and more people are looking for classes that are 45 minutes or less, and studios are beginning to shift to meet the demand—last year alone, there were 9 percent more classes on the roster that were less than 44 minutes.

The verdict: Expect to be adding a lot more shorter, higher intensity workouts to your roster in 2019. That is, unless you hop on the other biggest fitness trend of the year: The digital fitness boom.