Mom, I’m at the Gym Doing Homework (Really!)

IT is 5 p.m. on a Tuesday and Victor Cal and Suliman Sharif, both 14, have already taken Overtime Fitness in Mountain View, Calif., by storm. They hopped wildly on the flashing lighted squares of an In the Groove dance pad, rode stationary bikes, shared cellphone pictures, chatted with a personal trainer and played a rousing game of table tennis. The pair, friends since seventh grade, once spent five hours at this airy health club.

Conceived for teenagers, Overtime Fitness has a rock-climbing tower, a lounge area with a flat-screen television and a study room with Internet access and books like “The 7 Habits of Highly Effective Teens,” where teenagers can get academic tutoring and attend seminars on health, stress management and relationships.

Harried parents head to the gym with a purpose: to get in a solid block of cardio, then get out. Quick.

Teenagers think differently. They want a place to chill after school with pals, where they can go online, watch reruns of “The Munsters” and maybe even break a sweat. After a snack.

“Sometimes in the middle of our workout, we head down to the 7-Eleven to buy a hot dog,” said Suliman, a sophomore at Los Altos High School.

Until recently, health clubs passed over the hard-to-please teenage set and even had policies to keep them out. After all, what club manager wants to herd cats? But in the last year, smaller gyms have started wooing the MySpace generation. Most of the effort so far involves adding a teenagers-only lounge and Internet access, and creating centers with workout equipment, foosball tables and juice bars.

Many gyms offer child care, tumbling for toddlers, and youth and women’s programs, but the teenage market has been virtually untapped, making it appealing to clubs looking for the next big thing in a competitive business. At the same time, slashed physical education programs and the growing rate of childhood obesity have raised concerns among parents and the fitness industry.

Teenage memberships are up, with 3.4 million people ages 12 to 17 belonging to gyms in 2005, up from 2.6 million in 2002, according to a report from American Sports Data Inc. and the International Health, Racquet and Sportsclub Association. The addition of classes for teenagers at many gyms, including cycling, hip-hop and conditioning, has helped increase the numbers. But gym managers have since realized that it is not enough to just blast music by the Strokes during cycling sessions. Teenagers want more than retrofitted adult classes.

Teenagers want to exercise alongside their peers and feel that they belong. Trent Bowers, 17, of Los Altos, Calif., recently canceled his membership to 24-Hour Fitness. “I didn’t fit in there,” said Trent, a high school athlete. “Everyone there was older and a lot bigger than me. When I went to a machine I would always have to lighten the weights.”

He now enjoys weight lifting four times a week at Overtime Fitness following a program set up by an attentive trainer.

Sometimes attracting youngsters requires supplying machines they covet.

“I like to be with kids my own age, and it has to be fun,” said Christian Villarruel, 16, from Parker, Colo. To this end, Christian’s mom drives him 45 minutes to XRKade in Denver, an interactive fitness room in a converted warehouse that has flashing lights and technology-driven workout equipment, including virtual tennis, boxing and running.

Christian also said that he gets a high-intensity workout playing 3 Kick, which involves punching and kicking padded posts that make noise and light up. But the real point is besting his friends so that he is anointed highest scorer, if only for a day.

XRKade rooms have been installed at six schools, Jewish Community Centers and Y.M.C.A.’s nationwide, with plans for 12 more by year’s end, said Mike Hanson, the chief executive of iTech Fitness, the creator of the concept. The word “exercise” doesn’t appear in XRKade materials. Why? Mr. Hanson said his energetic clientele want to think they are just playing games.

Jill Stevens Kinney, the managing director of Clubsource Development Partners, a health club development company in San Francisco, said: “At the end of the day, what really drives this audience is that it’s a cool place, a place they want to be. If they don’t feel like it’s a place they want to hang out, they won’t have anything to do with it.”

Overtime Fitness was a teenagers-only gym but in July began admitting adults because of low membership. Everyone shares the equipment, but the teenagers have areas that are off limits to the middle-aged. Laura Tauscher, chief executive of Overtime Fitness, attributed low membership rates to logistics: its location requires pickup and drop-off for teenagers who do not drive.

Next June, a Club One is set to open in Petaluma, Calif., with a teenage center that has amenities such as Internet access, a lounge with a juice bar, a big-screen television and a foosball table. And at Life Time Fitness locations in Lakeville, Minn., and Deerfield Township, Ohio, racquetball and squash courts have been converted into activity centers for teenagers.

Spectrum Athletic Clubs, a chain with sites in California and Texas, has partnered with 02 Max, a company based in Los Angeles that focuses on teenage fitness, to begin a pilot program this fall at the Spectrum Club Manhattan Beach in El Segundo, Calif.

Within a dedicated space, 02 Max will have basketball clinics and nutrition counseling, a no-adults-allowed space and roaming Princeton Review tutors. The Manhattan Beach site also plans to have social events such as a battle of the bands. “It’s MySpace meets Starbucks,” said Karen Jashinsky, chief executive of 02 Max.

Such a space has great appeal to parents.

Suliman’s mother, Sameera Sharif, 39, pays $59 a month for his Overtime membership. “It’s a healthy environment,” she said, “even if they are just playing Ping-Pong and hanging out, rather than going to Starbucks where they are just drinking and sitting and eating.” She also hopes he will get into shape.

The question remains whether teenagers will exercise as much as surf the Web. Jonathan Kaye, 29, a personal trainer at Overtime Fitness, said he has had to pry teenagers away from the computer monitors.

Or will teenagers use unsupervised time to flirt? The Pacific Athletic Club in San Diego closed its teenage lounge in 2002. “From what I hear, there was a little bit of making out going on,” said Erin Adams, a receptionist.

There are other pitfalls to having coming-of-age clientele. To avoid what Kevin Kane, the general manager of the Saw Mill Club in Mount Kisco, N.Y., calls “roaming packs of teenagers,” the club’s code is posted throughout: No groups larger than four. No raising your voice above the level of conversation. No cellphone usage.

The staff is encouraged to punish misbehavior with eviction for the day.

“One teenager is wonderful,” Mr. Kane said, “but three or more is a pack.”