It’s the new zumba, if you will—the next trend in fitness classes. But instead of trying to figure out steps to Latin music or listen to counts from an aerobic instructor, you run through a row of tires, pull your body across a gym floor by means of a rope, do mini-sprints to move a stack of aerobic step risers from one side of the room to another, play tug-of-war and other hard-core, heavy-breathing exercises.

The key to group boot-camp training is using muscles in different ways, both inside and outside the gym building—increasing strength and aerobic fitness. Yes, there’s a military influence, but the boot-camp concept is more than that.

“I like to think of it as functional training, rather than your everyday ‘jump on a machine’-type training,” says Ray Ramos, assistant fitness manager at the Taylorsville Gold’s Gym. Ramos, who did a tour of Afghanistan with the U.S. Army’s 1st Infantry Division, started his own style of boot-camp training with two of his former platoon buddies. One class is called Military Body Training, the other is Military Boot Camp, both abbreviated as MBT. Both are group classes that use a personal-trainer approach to making people more fit.

“We picked up the military mentality of always being in shape, of ‘you’re only as good as how strong and agile you are.’ We’re more motivating than regular group classes,” he says.

It’s not only motivating; it creates bonding and friendship among the regulars in class. Most boot-camp classes are somewhat similar to CrossFit, another type of hard-core training with a “push yourself” foundation. In fact, do an online search for the words “boot camp” or “CrossFit,” and you’ll find millions of listings. The appeal may lie in the concept of pushing yourself and allowing the group effort to push you even further out of your comfort zone, either through trying to be the best or not wanting to be the last. Plus, it’s not like a drill instructor shouting in your face; the entire class is encouraging to each other, and the instructor helps you to reach deeper for strength you didn’t know you had.

Shannon Branca, who has taken the class for the past 10 weeks, says, “The group aspect makes me more competitive with myself—not with others, but with myself. I like the interaction you get with the trainers, and I feel like I’m part of a special group. I’ve gotten tremendously stronger, my endurance has dramatically improved, and I’ve lost inches during those 10 weeks.”

The gym’s fitness manager, Aaron Frost, has a startling prediction. He says, “In the next two years, group training like this is going to push one-on-one training out the door. It’s popping up everywhere. One good thing about it is you’re not the only one who may not be able to keep up; there’s others in the class that are at the same level you are. And everybody’s pushing themselves hard.”

Ramos says, “I see MBT as a hit in the future, because it gives people a chance to do a group class they can have fun with and still feel great afterwards. They get pushed to their limits and have a different persona for an hour. I’ve seen people change in the class. They’re more active, they drop body fat, they come to the gym more often. It’s definitely not easy. You learn a lot about yourself. The benefit of this kind of training is, you’ll become a lot more explosive and agile. You do a lot of core work, along with strength training. It’s a very well-rounded program.”

The first class is always free. After that, the 7 p.m. Tuesday class costs $15 per session. You don’t even have to wear camo.