At the sprawling 18,000-square-foot Brooklyn Boulders climbing gym, the theme song from Teenage Mutant Ninja Turtles pumps out of a sound system next to a 12-foot-high Adidas advertisement featuring 20-year-old climbing star Sasha DiGiulian. Eighty adults, all wearing purple, bounce off walls, yell, and generally behave like overcaffeinated primates. One guy hops from a slackline onto a series of mats, trying not to touch the ground. The crowd roars and the music rocks: Mi-chel-an-ge-lo is a party dude!

1,000 People per day taking up climbing at U.S. climbing gyms.

This is Brooklyn Boulders’ signature event, an obstacle race called the Lava Monster. The premise is simple—the floor is lava, so don’t touch it—and the rewards are pretty good: free beer for the runner-up and, for the winner, a coveted membership to the three-year-old gym, which has become a hub for New York’s adventure-sports community. Tonight, in mid-November, a week after Hurricane Sandy blasted the city, Brooklyn Boulders (or BKB) had to turn away 30 people who had hoped to pay $15 to race up the walls. “We brought partying to climbing,” says Lance Pinn, 28, the gym’s former-frat-boy co-founder, "and voilà."

BKB is a leader among a new group of climbing gyms: facilities that cater in equal measure to serious dirtbags and beginners from upper tax brackets who are ready to leave Zumba behind. A half-dozen big gyms have opened in the past three years in obvious places like Boulder and Seattle, but also in Atlanta, Montreal, and St. Louis, where a group called Climb So Ill just launched a 10,000-square-foot center in a former hospital power plant. More are coming, most notably Sender One, a high-end, 25,000-square-foot Orange County, California, facility co-owned by climbing icon Chris Sharma, and a Boston offshoot of Brooklyn Boulders equipped with saunas, a yoga studio, a café, and, according to Pinn, “a staff lounge of epic proportions.” The gyms are a far cry from the urban training dungeons that sprang up in the '90s, and climbing insiders hope they’re the beginning of a national movement.

“In Boulder and Salt Lake City, everybody gets it,” says Adam Koberna, U.S. sales manager for Walltopia, the Bulgarian company that is one of the world’s largest manufacturers of climbing walls. “But these other areas, that’s where the growth is: St. Louis, Chicago, New York. The U.S. is getting ready to explode.”

Some think that’s an ambitious assessment. “It’s a small industry, and we’ve got a half-dozen big projects that are running this way,” says Bill Zimmerman, executive director of the Boulder-based Climbing Wall Association. “Is that a trend? I don’t know. I do know that there’s a buzz about these places, and people want lifestyle facilities that aren’t hardcore climbing gyms.”

Just how imminent the explosion is may not matter, as long as marketers can sell the sport to open-minded yuppies. Which is already happening. Mountain Hardwear has a new lifestyle-oriented climbing line coming this spring, and Adidas Outdoors, a spin-off of the athletic-apparel brand, recently bought the climbing-and-biking-shoe company Five Ten and is supplying 26 urban gyms across the country with employee clothing.

“The outdoor-climbing market is not growing leaps and bounds,” says Greg Thomsen, managing director for Adidas Outdoors. “But gym climbing has a very strong growth rate. Something like 1,000 people a day are starting to sport climb, according to our research.”

Many are inspired by a new generation of climbers—the ones pushing the sport beyond its limits—who often train indoors, like BKB regulars DiGiulian, a Columbia University student, and 12-year-old Manhattan bouldering phenom Ashima Shiraishi.

Star power gives the sport cachet, but it’s the first-time climbers looking to try some bouldering, take a yoga class, and order a latte—or wear purple, hop off the walls, and scream—that have entrepreneurs like Pinn thinking about franchising. Once the Boston gym opens this month, Pinn is relocating to a new city (he won’t say which) to begin scouting a third location. “No one’s started a national climbing-gym chain,” he says with a smile. “Yet.”