The ICOR gym in Iowa City is exactly what you might imagine. The walls are cluttered with newspaper clippings of past matches and champions. Hovering above are trophies, belts, and medals marking accomplishments.

Most don’t know this gym. From the highway, its sign is barely visible. To find the entrance requires an adventure to behind Fin and Feather. Despite the gym’s discreet nature, the sport occurring inside, Muay Thai, is hardly a secret anymore.

“When you’re growing up and you’re a guy, you always want to be that cool tough guy. Like, ‘Oh, I’m just going to go beat up on people.’ Usual male-ego stuff,” said Henry Tomkovicz. “Then after a little bit it, just became more fulfilling. I no longer see it as a need to be egotistical or tough and cool; it’s just something I like to do.”

For the next three days, gym members Tomkovicz and Richard Glenn will put their hard work and training on the line when they compete against 335 Muay Thai fighters at the Thai Boxing Association Muay Thai Classic in Des Moines, starting today and lasting through the weekend.

Muay Thai, which originated in Thailand, is also known as the “art of eight limbs.” Fighters must combine the use of their hands, elbows, knees, and shins to defeat their opponents.

How the fighters came to Muay Thai differs with each gym member. Some were introduced by friends, some transitioned from traditional boxing, and others were looking for an alternative to the weight room.

What they share in common are benefits they all receive from one of the nation’s fastest growing sports.

“It’s the best stress relief I’ve ever found, and I’ve played sports my whole life,” Glenn said.

“Especially with school, you just come and leave all of that stuff at the door.”

In preparation for the tournament, Tomkovicz conditioned himself by running in the mornings, while Glenn swam and weight-trained. These are only part of a demanding regimen — both fighters also train for at least two hours daily: one hour each of boxing and Muay Thai.

Another challenge Glenn and Tomkovicz must face is making their weight class — 165 pounds and 142 pounds, respectively. Glenn said the last couple of days leading up to a fight consists of time spent in the sauna and drinking or eating next to nothing.

As the sport grows in popularity, those competing have differing opinions on why, including ICOR Muay Thai instructor Josh Johnson.

“I think it’s a bit of a primal thing,” he said. “As there are more and more advances in our society and technology moves forward, there’s that primal level of being as strong as you can be and being stronger than everybody.”

Johnson came to the ICOR gym nearly four years ago with no prior Muay Thai experience. With time, he developed a passion for the sport and now has been teaching Muay Thai for almost a year with fighters of varying experience.

“There are people from all kind of fighting levels coming in,” he said. “I have fighters competing this week, and a guy who’s never been in a gym before. I just like giving people those opportunities. That was me one time.”

Tomkovicz and Glenn’s competitive drive is clear: They both want to win. But it’s also clear that these fighters have found another reason to enjoy Muay Thai: The people they meet and the relationships they build.

“We’re a lot of ridiculously hard-working people,” Glenn said. “It’s good to be around people that have a similar mindset.”