The following is an excerpt from The Glass Box: The Shocking True Story of How CrossFit Broke the Rules, Made Millions, and Changed Fitness Forever, a new book about CrossFit’s history that features reporting and interviews with the people involved, including Greg Glassman.
The Black Box Summit
AT 1:45 PM on Saturday, November 21, 2009, a few dozen trim, healthy-looking men and women in their twenties and thirties were gradually returning to the aluminum folding chairs that had been arranged in the middle of CrossFit Central, having just finished a light lunch provided by the local Austin health-food chain My Fit Foods. A roughly five-hundred square-foot gym housed in a former body shop on Burnet Road in Brentwood, a flat, oak-lined neighborhood a few miles north-northwest of the Texas capital, CrossFit Central was founded in 2006 by Carey Kepler and Jeremy Thiel, siblings and former collegiate athletes who had been running boot camps in parks around the city before opening a place of their own. The air was mild but the slate-gray sky looked ominous—like a storm was coming.
Most of the people present were themselves gym owners operating CrossFit gyms—known in the business as “boxes”—in cities all around the country. Impressively muscled and swathed in athleisure, they had come to Austin at Thiel’s invitation to attend what had been dubbed the Black Box Summit—a three-day gathering of CrossFitters intended “for affiliates, by affiliates,” in the program’s official description. It was like an Apple keynote with an audience of Arnold Schwarzeneggers.
Thiel had put together the weekend with Dutch Lowy, a fellow Texan who owned a CrossFit box across from Texas A&M University in College Station. The event was inspired by CrossFit’s weekend seminars—conducted by CrossFit founder Greg Glassman and held at the original CrossFit box in Santa Cruz, California—which certified coaches in the methodology. The idea was to embrace the brand’s “open source” philosophy by pooling resources and sharing information, like a fitness-based meeting of the minds. “It was all centered around the CrossFit mentality of finding the best people, bringing them together, and figuring out what we can do to make this better,” Lowy explained. “That was the way CrossFit was initially developed: Take from the best in the business, develop a program that’s superior in every way, and always be changing.”
The desire to gather experts and showcase their unique expertise was one motivation for organizing the summit. The other was that CrossFit gym owners desperately needed help. Glassman was a dyed-in-the-wool libertarian with ties to the Cato Institute, the free-market think tank founded by Charles Koch. In business, he favored the “least rents” model in which a company would claim “a shrinking slice of the pie in a rapidly growing ecosystem.” CrossFit, Inc., charged prospective gym owners only a nominal fee for the rights to use the CrossFit name—just $500 in the early years—which Glassman boasted was a fraction of the capital required to open a Planet Fitness. But in exchange for this miniscule payment, box owners got nothing: no merchandising, no marketing materials, no business plan. Other than having a link on the CrossFit website, these budding entrepreneurs were on their own.
Granted, most people involved in CrossFit in those days appreciated the hands-off approach, at least conceptually. The price was so low that it was easy for boxes to justify, and the informality only added to the brand’s laid-back, renegade air. “There were these affiliates popping up all over the place, and there was really no regulation on what was going on,” said Michael Rutherford, a strength coach from Kansas City who was one of the summit’s plenary speakers. “It was like the old mining days in Leadville, Colorado. People were going out and sticking a flag in the ground and—boom— they were CrossFitting.” At the same time, the total absence of support meant that box owners—many of them former coaches without any real experience running a business—were struggling with standard operating procedures and best practices. It was a crisis that the Black Box Summit was designed to solve. “The original agenda was let’s help people get the answers they’re not getting as a CrossFit affiliate,” Rutherford said. If CrossFit wasn’t interested in providing this kind of information, they would have to provide it to themselves.
It was shortly before the summit, in mid-November, that Thiel arranged a call with the weekend’s speakers, including Rutherford and Lowy, and the box owners James FitzGerald, Greg Everett, Aimee Anaya, and Robb Wolf. He let them know that he’d called Glassman as a courtesy, to extend an invitation and to reassure him that they weren’t trying to steal any of CrossFit’s thunder. Glassman hadn’t seemed to have taken the news so well. “We’ll be there, because we have to keep an eye on what’s going on, not because this is fantastic and we want to be involved” was the gist of the response, in Lowy’s recollection. “It was very standoffish. Us against them,” Lowy said. Or as Rutherford put it, “CrossFit was clearly offended that this was going on. As if we were going to hijack the whole company and take everybody away.”
Everett was not surprised that Glassman was distressed, because this attitude was exactly what he had come to expect of him. Co-owner of the fourth-ever CrossFit affiliate, which he opened with Robb Wolf and his wife, Nicki Violetti, in Northern California, Everett often spent his weekends in Santa Cruz helping facilitate the certification courses. Though he was never as close with Glassman as Wolf, who thought of Glassman as a father figure, Everett had seen enough over the years to develop a clear impression of CrossFit’s mercurial founder: “It was very apparent to me that he was simultaneously this really intelligent, really charismatic guy, but extremely erratic, unreliable, and unpredictable,” he said. “We would joke constantly about how little we wanted to be legally associated with the CrossFit name, because we never knew what he was going to do. Was he going to bomb a building at some point? That was a running joke.”
To the people on the call with Thiel, word that Glassman knew about the summit was alarming. It wasn’t only Everett who had experience with his volatile temperament: Everyone involved in CrossFit knew that Glassman could be both charming and capricious, capable of both extravagant displays of generosity and sudden flashes of venom. “Greg is going to lose his mind,” one of the speakers on the call wagered. “He’s going to freak the fuck out. He’s going to think this is some kind of insurrection.” Thiel was adamant that it would all be okay. “No, no,” he assured them with characteristic brightness. “It’ll be fine. Everything is cool.”
Nevertheless, when Everett stood before the crowd as guests returned from lunch and took their seats at CrossFit Central that Saturday afternoon, he began to feel some serious trepidation.
It started the previous morning, when Everett walked into CrossFit Central right after dawn for the event’s 7 a.m. registration and found a familiar face already there waiting for him: Tony Budding, CrossFit’s longtime head of media and Glassman’s de facto right-hand man. Glassman had warned Thiel that he might send an emissary to attend the summit on behalf of the brand, someone who could represent the company’s interests and report back on whatever matters were discussed over the course of the weekend. But Everett had not been given a heads-up about this particular attendee, and to him it seemed like an ambush. “I was kind of like, what’s the story here?” Everett said. “This is not supposed to be anything to do with CrossFit HQ. Like, is he here to babysit? Is he here to report back to Glassman? It was a little weird.”
Both Budding and Dave Castro, a former Navy SEAL who had quickly become one of Glassman’s top lieutenants, had flown in from California for this event, though Budding maintained that they were welcome guests, or in any case, “certainly didn’t crash it.” Budding shared Glassman’s enthusiasm for debate and vigorous autodidacticism, and to his mind, the entire appeal of CrossFit was the intellectual stimulation its ideas could provoke. “You have to have a pretty involved background in the core questions of science, which is almost indistinguishable from epistemology, in order to understand why things were conveyed in a certain way rather than in other ways,” Budding explained. “I’ve always loved passionate debates. You get the best results from that. And if you’re a skilled debater, you make it about the ideas, not the person.”
The debates were harmless enough, in the beginning. At 11:15 a.m. on the first day of the event, Nicki Violetti gave a talk under the title “Introducing New Clients to a Program and Dedicated Points of Entry,” which touched on “On-Ramp,” a brief introductory session for new members designed to teach them the basic principles of CrossFit and ease them into the program’s intense regime. The idea, Violetti explained, was to mitigate the risk of injury and reduce the likelihood that someone might be overwhelmed: Don’t throw newcomers into the deep end, she advised; instead, let them slowly wade in. But this was starkly opposed to how the CrossFit methodology was taught at its own seminars. “The needs of Olympians and the needs of our grandparents differ by degree, not kind,” Glassman often declared, touting the accessibility of the program. From his seat in the crowd, Budding raised the issue and fervently disputed the point: Throw them in the deep end, he argued. How could anyone who coaches CrossFit not understand?
But it was during Wolf’s talk on “Nutrition in a Box” on Saturday morning that the mood in the room took a notable shift. A successful nutritionist and an early proponent of what he referred to as “the Paleo solution,” Wolf had frequently found himself in opposition to Glassman and CrossFit’s most loyal adherents, butting heads with his friend and mentor over the issue of the ideal diet for someone practicing high-intensity exercise. Glassman had long advocated for a low-carbohydrate, high-fat diet, and at the time had partnered with the dietician Barry Sears to promote his faddish Zone diet as part of CrossFit’s program. Though both diets involved cutting out grains and sugar, Paleo emphasized whole, unprocessed foods, akin to what might have been eaten by our ancestors millions of years ago, while the Zone focused on food categories—ratios of carbohydrates, fat, and protein—and was ambivalent about food quality. There were those within CrossFit who believed that it didn’t matter which specific diet someone followed so long as they were making predominantly healthy choices. But many at the top—including Castro—saw this quibble as a seismic fracture.
Though Castro had only been involved in CrossFit for a couple of years, he was rapidly becoming one of the most prominent figures in the growing organization, in large part because of his role as the frontman of the CrossFit Games, the now annual competition the brand had organized three years running on Castro’s family ranch. But among those present at the Black Box Summit, Castro had a different reputation: He was regarded as Glassman’s heavy. “He was a racehorse that was beat down and groomed and shown what to believe and how to talk. He was honestly Greg’s enforcer,” Lowy said. “Greg needed somebody like that, who could go in and be an asshole so that he didn’t have to. He would step into places where Greg didn’t want to be and he would cause a disruption.” If the speakers were apprehensive about Budding’s presence at the summit, Castro’s presence was enough to make them fear the worst. Wolf in particular was all but certain of it: Glassman had sent Castro to cause a scene.
Excerpted from THE GLASS BOX: The Shocking True Story of How CrossFit Broke the Rules, Made Millions, and Changed Fitness Forever by Calum Marsh. Reprinted with the permission of the publisher, HarperOne, an imprint of HarperCollins. Copyrighted © 2026 by Calum Marsh.
Calum Marsh is a journalist and the author of The Glass Box: The Shocking True Story of How CrossFit Broke the Rules, Made Millions, and Changed Fitness Forever. His bylines have appeared in The New York Times, The New Yorker, and The Guardian, among others.