Correction: An earlier version of this story gave the incorrect college where Camille Lanier played squash. It was the University of Pennsylvania, not Dartmouth. This version has been corrected.

Amir Wagih, left, and Eunice Tan, coaches at Squash on Fire in the District, practice at the company’s new $12 million boutique facility on M Street NW. (Tim Van Asselt)

To a casual observer, the game of squash looks easy.

Contested in an enclosed court, players serve the ball toward the back wall and aim to hit the ball before it bounces twice and also make their opponent miss the ball. The first person to 11 points wins.

Pretty simple, right?

But to those who love the game, squash is a rigorous endeavor, both physically and mentally.

Fabien Sarran, a longtime squash player and the coach of Squash Revolution at Sport&Health gyms in the Washington area, said squash is a full cardiovascular and strength workout, akin to high-intensity interval training — minus the burpees.

Squash, a court game in the same vein as other racket sports such as tennis and racquetball, was started in England in the 1830s by children in prep schools. Because it’s squishier than a tennis ball, the squash ball exerts less force as it hits the wall, requiring some quick mental calculations. And there isn’t much room to roam in the squash court (usually 21 feet by 32 feet), so each step is a calculation as well. Playing squash well requires strong racket control, good timing and excellent hand-eye coordination.

Alejandra Porras, a 2015 graduate of George Washington University who played on its varsity squash team, grew up playing squash in her native Colombia.

“I sweat more [playing squash] than playing any other sport. So, I don’t know if it’s psychological, but I feel like I do burn more calories,” she said.

Squash is a popular sport among the British Commonwealth countries and throughout Europe but has ebbed and flowed in popularity in other places, particularly in the United States. Sarran said most people have heard of squash but don’t quite know what the game entails.

Those who love squash admit that growing the game has been a challenge.

“It’s a very expensive game and a very unique game,” said Amir Wagih, the head coach at Squash on Fire in the District.

Sarran said that in the District, the availability of certified squash courts is the ratio of 1 court to 10,000 squash players. When Squash on Fire opened its doors at Sports Club/LA (which was purchased by Equinox) in 2014, across from its new facilities on M Street NW, demand for squash courts was off the charts.

“I had 67 bookings for four courts. This has never happened,” Wagih said.

Squash is also perceived as an elite sport. Courts are found in clubs that charge hundreds of dollars for membership. (Also, U.S. Squash, the sport’s national governing body, notes that the median income of players is almost $300,000 and that 98 percent have college degrees.)

Nevertheless, a movement to democratize the game is afoot in the United States. The Sports and Fitness Industry Association found in a recent survey that squash was the 12th-fastest-growing activity in the United States, with 1.7 million participants. Participation has grown 32 percent since 2012, but it is still seen as a niche sport. (By comparison, stand-up paddle-boarding is the fastest-growing sporting activity, with more than 3 million converts.)

Squash on Fire moved to its new home, a $12 million boutique facility, on May 20, as part of the West End fire station project developed by EastBanc, headed by Anthony Lanier. The D.C. real estate developer and his family share a passion for squash. Wagih trained Lanier’s youngest daughter, Camille, who was a top player at the University of Pennsylvania. That partnership with the Lanier family brought Wagih to the District as part of Squash on Fire.

Nadine Arsenyev, an EastBanc real estate executive based in Russia and Lanier’s eldest daughter, describes squash as an addiction.

“There’s nothing repetitive” about squash, she said. “There’s a hundred different angles, a hundred different shots.”

With its pay-to-play system, Squash on Fire hopes to capi­tal­ize on the boutique fitness boom while lowering the barrier of entry for squash players who wouldn’t want to pay a gym membership fee.

Dan Heinrich, an official at U.S. Squash, said the organization has focused on empowering coaches and elite players at the local level to garner interest in the game. The association launched its Club Locker app, which allows players to submit game and tournament scores and track live gamecasts of featured matches, as well as find available squash courts in their area.

Officials with the World Squash Federation lobbied numerous times to include the game in the Olympics. After another denial for the 2020 Games in Tokyo, they are hopeful for its inclusion in the 2024 Games.

At the collegiate level, squash is still seen as what Heinrich called a “backdoor” way to get an athletic scholarship, especially at top schools such as those in the Ivy League.

Even if it doesn’t lead to an Ivy League education, coaches and players say learning how to play squash well is a complete workout, using both the body and brain at a high level.

“It’s not just a physical activity, but I believe it’s a mental activity, outside of my regular work,” Porras said. “Some people feel chess is a good activity for their brain. For me, it’s squash.”