Yoga instructors are accusing America's largest chain of yoga studios of underpaying its teachers. More than 1,500 yoga instructors have joined a class action lawsuit against CorePower Yoga, claiming CorePower teachers "are overstretched and not being paid the minimum wages they are entitled."

"CorePower probably started out with a mission and a goal that they wanted to bring yoga to everybody, but then it turned into a way to monetize," instructor Effie Morgenstern told "CBS This Morning: Saturday" co-host Dana Jacobson.

"It's a business that is hiding behind the guise of yoga," another yoga instructor Melissa Brennan said.

Malissa Brennan and Effie Morgenstern CBS News

Brennan and Morgenstern said during their years teaching at CorePower Yoga, the company didn't pay them what they were legally entitled to.



"Once you get the job, you're expected to be compensated for the work you do off the clock," Morgenstern said. "Frankly $15 an hour does not compensate you for that work you do off the clock."

"What is that work... and how much time are we talking about?" Jacobson asked.

"We're constantly having to change our playlist, constantly having to sequence, testing it out," Brennan said. "The expectation is go off... do all of this work and then come back and bring it back to the studio."

They said for every one-hour class that they taught, they had to put in up to an additional six hours – unpaid.



They claim the company is in violation of the fair labor standards act by failing "to pay its instructors for certain hours worked, causing their average weekly compensation to drop below the minimum wages they are entitled."



"They hide behind the fact that you have all this gratitude and love and appreciation for yoga and your peers, and we met this way," Morgenstern said.

"In a lot of ways they weaponize relationships," Brennan said. "I know there is a part of me that feels really foolish for really buying into that and thinking that these people did care about me."

The suit, the fourth class action with similar complaints against CorePower, also addresses how the company pressures instructors to recruit students to sign up for a $3,000 teacher training.

"Part of your performance is based on how many people you recruit into the teacher training programs," Brennan said.

"Because they make a lot of money off of those teacher training programs," Jacobson added.

"They do," Brennan said, adding, "They… intentionally keep your wages low unless you do things like sell their teacher trainings, unless you recruit more people into the fold, until you grow that community."

"Somebody would say that's an incentive based. So you have pay but that's your incentive. Why isn't it that?" Jacobson asked.

"When you have a place... that is just charging the maximum, profiting off of their students, dragging people into teacher trainings, and then pouring out teachers... it just dilutes the whole spirit of yoga," Brennan said.

Sheetal Shah agrees.



"It's absolutely anti-yoga," Shah said.

She launched the "Take Back Yoga" campaign to highlight the Indian roots of the ancient philosophy.



"It just goes against the very basic tenets of yoga, satya, truthfulness," Shah said. "And you're violating that by telling teachers to prey upon students who may or may not be good as teachers and bring them in for the sole purpose of making money."

Brennan now works out of independent yoga studios, and Morgenstern said she still works at CorePower because some money is better than none.



"I don't really have a need to leave aside from the underpayment," Morgenstern said.

"You'd rather make it right?" Jacobson asked.

"I'd rather right and I'd rather make it known that we are underpaid," she responded.

In a statement to CBS News, CorePower Yoga said this lawsuit is without merit and maintains there was no wrongdoing. The company adds, "CorePower is proud of its practices, believes they are fair and will continue to stand by and defend them." The case is expected to be settled out of court, and those three other lawsuits we mentioned were also settled.