Like movie theatres and libraries, many fitness clubs have insisted for years that their workout areas should be cellphone-free. Their logic is as simple and straightforward as a push-up: They want to prevent people from yakking on their phones and annoying the fitness buffs who want to crank out reps and mileage in relative peace. Safety is another reason, because texting while running on a treadmill can be hazardous to your health.  

But what makes sense in theory is becoming harder to police in practice. Gym owners say their members are dividing into two camps, those who can’t stand cell phones on the gym floor and those who see their phones as indispensable to their workouts as a bottle of water.  

The whole issue has grown more complicated as phones themselves have grown more multifunctional. Many phones now double as a music player and have apps like Gym Buddy to track crunches and deadlifts. And iPhones can be docked into some cardiovascular machines made by Technogym and Cybex to enliven an otherwise boring workout by watching videos like Lady Gaga’s “Edge of Glory.”  

Phones can also shoot video as well as take pictures. So while it used to be easy for club managers to tell if a loud talker was flouting the cellphone ban, employees have to keep an eagle eye out for people who might be shooting another member’s jiggling belly fat for a laugh.  

“It started out as a member-annoyance thing,” Scott Rosen, the chief operating officer of Equinox, said of its ban on phone use in exercise areas except as music players, a policy that it reminds members of with signs in its 55 gyms saying: “Can you hear me now? Cell free zone.”  

“Now privacy and security concerns have come into play,” Rosen said.  

In its 92 clubs, Life Time Fitness bans taking photos and videos, and discourages gabbing on the fitness floor. “The last place someone wants to be filmed is working out,” said Karen Jayne Leinberger, a company spokeswoman. “That’s your private time to get a sweat on. It’s not flashy, attractive or sexy, unless you’re Ronnie from ‘Jersey Shore.”’  

Not to mention, a workout video could end up on YouTube in a blink. Recently, one such video of a woman twirling creatively on a treadmill at a Planet Fitness gym in El Paso, Texas, passed a million views. The woman, Nicole Harris, said she gave permission to the fellow member to film her.  

But the video nevertheless is a reminder that in the age of the camera phone, any gym patron can find that his or her private workout moments are on the Internet (there are plenty of unauthorised and unflattering examples on YouTube).  

Many people applaud any efforts to crack down on cell phones on the gym floor. Tinamarie Guaglianone, 40, who works out at Equinox in Greenwich, Connecticut, said she has seen people curling a weight with one hand and checking email with the other. Some people even interrupt their personal training sessions to take a call, she said.  

But some people say they can’t cut themselves off from their phone mid-workout, even while they’re logging kilometres on a treadmill.  

“I can run and check Facebook,” said Pam Fisher, 30, from Fort Edward, New York, who goes to a nearby YMCA which has no national ban on cellphone use while exercising. “I’ve definitely texted people.”  

Jim Evans, the vice president of four Bay Area Family Fitness gyms near San Francisco, who has been in the fitness industry for 45 years, said that gyms should impose across-the-board bans on cellphones to end all of the arguments and concerns over safety and privacy.  

“In the long run for our industry, that’s the only solution,” said Evans, whose gyms discourage cellphone use on the floor and prohibit it in locker rooms. “It’s going to get worse, not better.”