DENVER » It was evening at one of this city’s most popular yoga centers, and teacher training was about to begin. Students wore flowing genie pants. Votive candles lit a classroom. Annie Prasad Freedom, the studio’s founder, greeted arriving yogis.

"Hello," she cooed to a man with dreadlocks. "Nice to see you."

Bubbling beneath the evening’s placid veneer, however, was a debate that has riled Colorado’s growing yoga world, pitting studio owners like Freedom against a government agency that says programs that train yoga teachers must be certified, just like schools that prepare barbers, cosmetologists and truck drivers.

"I get pretty fired up about this new thing with the government," said Freedom, 45, sitting outside her studio, Samadhi Center for Yoga and Meditation. "How can you have people who know nothing about yoga regulating yoga schools?"

Studio owners say the rules – which involve paying hundreds of dollars in fees and submitting curriculums for approval – will cut into their tiny profits and limit their yogic creativity. But officials of the state agency, the Division of Private Occupational Schools, say they are trying to protect aspiring teachers from fraudulent and unsafe programs. And they point to the case of Bikram Choudhury, a well-known yoga teacher accused of sexually assaulting students, as evidence that schools need government supervision.

"We’re not here to gouge the little guy," said Lorna Candler, director of the agency, who is herself a yoga instructor. "We’re just here to uphold the law."

Candler’s division has announced a temporary cease-fire, saying it will not enforce its rules until after a March 24 meeting of its board. A group of yoga buffs, meanwhile, has persuaded state lawmakers to introduce a bill that specifically excludes the training programs from agency oversight.

The bill passed in a Senate committee hearing on Wednesday, inspiring one Republican lawmaker and yogi to leap onto a desk and strike a crow pose, balancing his knees on his elbows. The bill has not been introduced in the state House.

The fight here is just the latest in a continuing debate over whether yoga instructor training programs should fall under the supervision of state agencies that certify occupational schools. The number of teacher training schools has exploded in recent years, jumping nearly 20 percent in 2014 alone, according to the Yoga Alliance, a nonprofit industry group. (The group counted 3,492 schools worldwide at the end of 2014.)

Some warn that this leaves aspiring instructors vulnerable to fraud. Courses can cost $3,000 or more. And while the Yoga Alliance has run its own certification program since 1999, skeptics worry that self-policing is not enough.

Several states have tried to force yoga schools to seek licenses, only to have their efforts repelled by angered practitioners. In 2010, New York yoga enthusiasts pushed through a law that excluded their schools from rules governing occupational schools. At least three other states – Texas, Virginia and Arkansas – have passed similar legislation.

Here in Colorado, where physical fitness is approached with fervor, yoga studios have proliferated in the past decade, along the streets of Denver and in even the most out-of-the-way mountain towns. Competition for students is fierce, and the debate over government supervision has been laced with accusations that the state is pushing out small schools by forcing them to pay a fee that begins at $1,750.

Candler, who is leading the regulation effort, is a yoga instructor at CorePower Yoga, a national chain with 22 locations in Colorado, and her dual role has only heightened such concerns.

"It’s really sad," said Michelle Voeller, 38, owner of Harmony Yoga, who said she recently shut down her teacher training program after learning she would have to pay a fee of nearly $2,000. "The bigger people will survive, and the smaller people trying to do really authentic work will suffer."

Technically, Colorado’s Division of Private Occupational Schools has required yoga teacher training programs to apply for certification since 1981, mandating that studio owners pay a fee, fill out paperwork and present their program before a board.

But few schools complied. Then, in October, a yoga instructor named Sandy Kline sent a letter to the agency, naming 85 schools that she believed lacked state certification. Officials quickly began a crackdown, sending compliance letters to 50 yoga programs.

In an interview, Kline said she was driven by concerns that "risky" techniques were being taught, and that students could be swindled by fly-by-night operations.

"Why should yoga training schools be exempt?" Kline, 61, said. "Are they that special that they shouldn’t be examined?"

The state’s demands, however, concerned some yoga school owners, who gathered at a January meeting held by the Division of Private Occupational Schools to voice their complaints. The discussion lasted more than an hour.

Central to the debate is the question of whether yoga instructors are hobbyists or professionals.

The state has argued that yoga schools are marketing their courses as occupational incubators, using the word "teacher" and instructing participants in how to market themselves to employers. But studio owners have said that few graduates make a career of their training, instead using it to inform personal practice or to teach courses for small fees in addition to other jobs.

Candler has said that her position as a yoga teacher is not a conflict of interest, and that she has handed day-to-day tasks related to yoga certification to a deputy, to avoid the perception of conflict.

"A lot of people said, ‘Look we’re teaching love and compassion, how do you regulate love and compassion?’" she said. "No one likes to be regulated. But there needs to be some kind of regulation in order to ensure there is some kind of order."

© 2015 The New York Times Company