A long-brewing tension between a well-known traditional fitness accreditation group and CrossFit may be heading to court.

Earlier this year, CrossFit filed a suit against the National Strength and Conditioning Association over a study published in the group’s journal claiming that a high number of CrossFit participants drop out before completing the program.

Lawyers for CrossFit alleged that the study, which was done by Ohio State University professor Steven Devor, was falsified and done erroneously.

“This lawsuit is happening not just because of a single study but of a pattern of them using their journal and their academic writings to publish false information about CrossFit,” said CrossFit spokesman Russell Berger. “And it’s not just us. We have 10,000 affiliates which are [run by] small business owners.”

In the lawsuit, lawyers for CrossFit allege that the NCSA and other similar organizations have taken aim at CrossFit because it has brought more competition into the fitness market and the study was one of many attempts by the organization to discredit it.

In the complaint, lawyers frame the motivation of the NCSA for publishing the study as a fight over the certification model. While most gyms and trainers have certifications from organizations such as the NSCA, that is not required of CrossFit instructors.

“Like the NSCA and ACSM, CrossFit makes a significant portion of its revenue through the certification of CrossFit trainers,” lawyers for CrossFit wrote in court papers. “CrossFit, Inc. offers its initial Level I Trainer’s course, as well as both advanced and specialty courses. CrossFit’s ascendance therefore threatens the revenue stream of the traditional fitness providers.”

Whether it threatens traditional fitness providers or not, it is indisputable that in the past decade CrossFit has exploded in popularity. According to court papers, it’s grown from a single gym in 2000 to 10,000 CrossFit locations with more than a million participants. There’s 80,000 Level One CrossFit trainers.

So when the NSCA published a study in its journal questioning the injury rate of CrossFit, which Berger told USA TODAY Sports is similar to that of any other exercise regimen, it is hardly surprising that CrossFit didn’t just ignore it.

“This case is about a supposedly ‘scientific’ study that Defendant National Strength and Conditioning Association (the “NSCA”) published to attack one of its competitors, CrossFit, Inc. (“CrossFit”). The study is based on data that is objectively false. Specifically, it reports that 9 of the 54 participants in the study dropped out of the CrossFit program being evaluated due to ‘injury or overuse.’ That simply is not true,” CrossFit’s lawyers argued.

Earlier this year, Berger published a transcript on his blog of a conversation he claimed he had with Devor. He also told a USA TODAY Sports reporter that a CrossFit participant, identified in his blog as Chelsea Rankin, who volunteered to serve as Devor’s research assistant for the study, contacted him to inform him of her doubts about Devor’s work.

Despite the injury rate, the study also points out some of the positive effects CrossFit has on its participants.

Devor did not immediately return a request for comment.

In the suit, CrossFit’s lawyers go on to blast NSCA and the American College of Sports Medicine for holding tight to the status quo of exercise. “In short, the NSCA and ACSM are largely responsible for maintaining the status quo in the massive fitness industry, and they have a vested interest in doing so: they obtain significant revenues charging for the certifications and training services based on it,” the suit continues.

On CrossFit message boards, a thread dedicated to attacking the NSCA and the journal’s editor-in-chief appeared. “What happens if you take a group of people with no CrossFit experience and have them do “Linda” as fast as possible, without coaching and using heavy weights? Answer: Four studies by the William Kraemer, Editor-in-chief of the NSCA’s Journal of Strength and Conditioning Research,” one reads.

In a statement on its website, the NSCA promises to defend itself vigorously from the lawsuit.

“The NSCA is a research-based nonprofit organization committed to the highest standards in its publications, certifications and educational services,” the organization wrote on its website.

“As the worldwide authority on strength and conditioning, the NSCA is dedicated to promoting the application of best practices among its thousands of members and certified professionals around the world.”

The two sides are due to have a phone call to encourage mediation in August.