WASHINGTON — Gyms in the District are already adapting to the so-called “yoga tax,” and now the D.C. Council is considering a proposal that would require trainers be licensed by a board in the city.

The prospect of certification was among the issues bringing CrossFit gym owners together for a rally Friday afternoon.

Greg Glassman is the CEO and founder of CrossFit, a chain of gyms across the nation. The largest concentration of CrossFit gyms is in the District.

Glassman and gym owners spent the week meeting with members of Council over the proposal.

“We’ve been assured by the Council by the deputy mayor that nobody wants to see anything bad happen to CrossFit, we know about the good works,” Glassman says. “Some of them are in our gyms, their families are in our gyms.”

Andrew Killion is the owner at District CrossFit — the gym that hosted the event.

He says that the tax on fitness is dissuading possible members from working out in the District. Killion says the certification will further threaten the survival of his business.

“If we’re looking at rising unhealthy populations in DC and in the country, I don’t see how reducing the supply of gyms is going to help the long term success of the health of the country and DC,” Killion says.

Glassman says D.C. would be the first jurisdiction in the nation to require such licensing standards. Killion says he doesn’t need a piece of paper to prove that he knows.

“I don’t think the regulation would make the trainers any better. It would just make it more expensive and more difficult to enter,” Killion says.

Glassman says this is part of a larger national agenda pushed by sports medicine and soft drink groups threatening gyms like CrossFit.

“The most dangerous thing about CrossFit is not doing it,” Glassman says.

WNEW D.C. Bureau Chief Kris Ankarlo contributed to this report. Follow him and WNEW on Twitter.