joshchambers's Public Library

People also tend to fall into two categories regarding self-control, she said — those who want to act immediately even if the action might be foolhardy and those who sit on the couch and procrastinate. There is overlap, but most people fall into one of these two groups, she said.

Mr. Adler and Mr. Robinson see the potential for big long-term growth for the Sitaras club through several avenues. Those include the possible expansion of the center’s new digital tracking room into clubs in major cities across the country and the planned rollout of a software app that will let everyone — even nonmembers — gain access to the Sitaras program online, on mobile phones and on tablets for a monthly fee.

 “My goal is to make fitness accessible — not just for the rich and famous,” Mr. Sitaras says. “My goal is to help everyone.”

It’s Mr. Sitaras’s proprietary personal training program that separates his center from other high-end clubs. Under the program, clients must undergo six hours of mandatory tests, spread out over six visits, that measure the strength, flexibility and endurance of more than 35 major muscles and joints.

 The results are then entered into a software program that Mr. Sitaras designed. It uses more than 5,000 variables, he says, to draw up a personalized fitness program. All clients must commit to at least two personal training sessions a week. Each of their workouts is tracked and monitored, and the program is adjusted as fitness improves.