When Josh Newman founded CrossFit NYC ten years ago, he says he wasn’t sure he’d be able to keep the lights on.

“When we moved into a space of our own, we had 20 members and we needed 30 to break even. And I wasn’t sure there were 30 people in New York City who wanted to do CrossFit,” says Newman. A tech entrepreneur and mixed martial arts competitor, he says he came across the competitive fitness regimen of CrossFit online, getting hooked before deciding to open his own gym.

Luckily, it turns out there were plenty of New Yorkers looking to “get the crap kicked out of them,” as Newman says. CrossFit NYC doubled in size in one year, and continued to grow quickly from there. Today, the gym boasts more than 2,000 members.

Newman says there are a few secrets to CrossFit NYC’s success – some more obvious than others. Here are the tips he’s passing on to other CrossFit fanatics-turned-entrepreneurs in the Big Apple:

No. 1: Focus on the core business offering.

Newman says CrossFit NYC never really engaged in any traditional marketing.

“Instead, we try to focus on the quality of the training that we provide and the results that people get. I think that people join a gym because they want to get in shape and they want to look better naked … the degree to which you’re delivering that is the degree to which they’ll keep coming back and tell their friends,” says Newman.

No. 2: Study your data.

Having built and sold tech companies Sharkbyte and Powerdime.com in the early days of dotcom, Newman is no stranger to running a business. And while running a gym and building a technology startup seem quite different on the surface, Newman says there are more similarities than one might think.

“It’s an iterative process. You have to look at the data and you have to look at your customers, and you have to each day be a little bit better and a little bit savvier in the way you run stuff. So, I think that the management of a good CrossFit box and the management of a technology startup are almost identical,” says Newman.

No. 3: Remember that no detail is too small.

One of the best lessons Newman passes along comes straight from the founder of CrossFit himself, Greg Glassman.

“[Glassman] said early on when he visited a CrossFit box, he’d go look in the bathroom and see if it was clean. And I think that’s absolutely right. If you can get the bathrooms clean, it probably means that all of the processes and all of the workflow in your business is working – and you’re getting it down to those last details that really matter,” says Newman.

Follow Gabrielle Karol on Twitter @GabrielleKarol