At 12:30 p.m. on a Tuesday, the chief executive of Datalogix was spider-crawling across a conference room floor. All around him, account managers and data analysts were thrusting 20-pound medicine balls overhead, while their Spandex-clad co-workers sprinted up and down the lobby’s carpeted staircase.

A panting, red-faced software developer rested against a railing as a colleague rushed past.

“Push it, Karin!” she cried in encouragement.

Minutes later, having regained her strength, the developer was back in the conference room, completing her fourth set of jumping squats while a muscle-bound trainer studied her form.

Since the summer of 2010, Datalogix, in Westminster, Colo., has offered these classes, called CrossFit, twice a week for its employees. CrossFit gained early popularity among law enforcement officers and military personnel, but lately, both large and small businesses — judging that fitness programs can bolster employee morale, improve productivity and reduce health insurance premiums — have taken an interest.

This fast-growing fitness trend combines weightlifting, gymnastics and endurance training and has attracted more than 10 million practitioners around the world, according to the company, about 60 percent of them women.

“My enthusiasm for CrossFit knows no bounds,” said Eric Roza, 45, Datalogix’s supremely fit and upbeat chief executive.

In fact, his enthusiasm led him to open with his wife a 10,000-square-foot gym in downtown Boulder, Colo., called CrossFit Sanitas, where he generally works out at 5:30 a.m., five days a week, although he will occasionally join his employees, too.

Roza used to run 100-mile ultramarathons, but he took up CrossFit after an injury in 2008.

“I got hooked instantly,” he said after the conference-room workout, his army-green T-shirt damp with sweat. “It was like crack or heroin.”

So when some Datalogix employees organized their own weight-loss competition three years ago, to see who could lose the most pounds, Roza began offering CrossFit classes in-house. He hired Pat Burke, the owner of another local CrossFit gym — or “box,” as it’s often called because of its spare, no-frills design — to teach the classes.

Burke, a former Marine, brings in barbells, gymnastics rings and medicine balls, depending on the day’s workout. To vary the routine, he might show up with tractor tires, which Datalogix staff members flip and pound with sledgehammers in the parking lot as their less gung-ho colleagues stare from the windows. Roza estimates that 50 of the 200 employees at Datalogix’s headquarters have taken part in the CrossFit classes. The participants, who sign a waiver of liability for injury, have shed around 300 pounds collectively — or at least that is the figure that Roza derived from informal employee interviews.

There are other, less quantifiable benefits. Karin Eisenmenger, 46, Datalogix’s director of order management and the woman running up the stairs past her panting colleague, says the classes unite people from different departments who might otherwise never meet.

“If you can sweat and groan and moan with your co-workers,” she said, “you’ll have no problem working with them in a meeting.”

CrossFit was started in 2000 in Santa Cruz, Calif., by Greg Glassman, a former gymnastics coach. Over the next decade, it grew from a single gym to a global workout craze. (There are now 42 CrossFit boxes in South Africa alone.) In 2010, a partnership with Reebok further raised CrossFit’s profile. Reebok has built 15 gyms inside or near its offices around the world and plans to open 11 more. In most cases, Reebok employees receive their membership at a discount.

The largest gym — known as Reebok CrossFit One, a cavernous, 12,000-square-foot space with six on-site coaches, 14 climbing ropes and one cargo climbing net, among other equipment — is at Reebok’s headquarters in Canton, Mass. According to Chris Froio, Reebok’s global head of fitness and training, more than 300 employees visit the gym every day. Like most CrossFit gyms, CrossFit One offers classes for a variety of skill levels, and workouts are scaled according to ability.

So it isn’t unusual to find Anne McKay, 74, an accounting clerk, carrying 5-pound sandbags beside Kenneth Gamble, a former running back for the Kansas City Chiefs and a Reebok executive, whose sandbags of choice often exceed 100 pounds.

Such exertions, without appropriate supervision, can lead to injuries. In 2008, Makimba Mimms, a former Navy information systems technician, sued a World Gym, a CrossFit affiliate training company and one of its employees in Manassas, Va., contending that an especially intense CrossFit workout caused a condition in which muscle fibers deteriorate and enter the bloodstream, leading to kidney damage. A jury awarded Mimms $300,000 in damages.

To prevent injuries, Reebok says its coaches at CrossFit One closely monitor all participants, who are also required to sign liability waivers.

Dr. Toni Yancey, a professor of health services at the University of California, Los Angeles, is all for people getting more exercise at work. But she says she thinks that incorporating movement into sedentary office routines makes more sense than pushing something like CrossFit, which is unlikely to engage a large portion of the average workplace.

“Dance breaks, walking to meetings together, sitting on balls — these things integrate physical movement into the daily routine,” she said. “And you don’t have to shower afterward.”

The need to shower hasn’t bothered the avid users at Reebok’s centers, and other companies have taken notice. ESPN and the sports retailer Finish Line consulted Reebok in designing their own CrossFit boxes. In 2011, Glassman helped put a team of Microsoft senior engineers through a weekend-long Level 1 Certification course.

“There are now 40 CrossFit trainers inside Microsoft,” he said, “and they’re teaching other people how to do it.”

James Letchford, CrossFit’s chief marketing officer, said that “a couple hundred” companies in the United States and Europe offered classes and subsidized memberships for their staff.

CrossFit’s ability to foster camaraderie among co-workers — at least among those motivated to experiment with Olympic-style weightlifting — is especially suited to the life-swallowing rigors of startup culture.

“A battle-hardened Green Beret once told me that CrossFit taught him the recipe for camaraderie, which is agony coupled with laughter,” said Glassman, who is 56. “He was talking about combat situations, but I’d expect to hear the same from guys writing code.”