MOUNTAIN VIEW, Calif. — Stephen Wallace hopped off an elliptical machine and got a pep talk from his personal trainer about his bench-press goals. Wiping away sweat, he said social commitments can make it hard to get to the gym every other day.

Wallace isn't a busy professional squeezing in lunchtime workouts; he's a skinny 16-year-old with braces and a backward baseball cap. He's working out at Overtime Fitness Inc., one of the nation's only gyms for teens.

"At other gyms no one would sit down and teach me how to use the weights or the machines," said Wallace, a junior at Palo Alto High School. "Here, you get a lot of personal attention and that gives you motivation."

Wallace's mother pays the $59 monthly fee at Overtime, a Mountain View gym that has about 100 teen members and hopes for regional and even national franchises.

The gym offers a mix of conventional training equipment — treadmills, free weights, yoga mats — and kid-friendly features like a rock-climbing wall and cheerleading conditioning sessions. It also tries to appeal to teens with an arcade featuring video games requiring kids to box, dance and jump. Riders race against each other on stationary bikes.

Although fitness enthusiasts applaud the company's effort to reduce the rising incidence of teen obesity, public policy experts say its very existence is a by-product of school budget cuts that have led to fewer physical education classes and after-school sports programs.

Others question Overtime's use of video games — a tactic that won't necessarily compel kids to keep exercising as they grow up.

Investors and employees — including founder Patrick Ferrell, who launched GamePro Magazine and helped establish the video game conference E3 — say high-tech toys lure some teens. But they say the gym also offers nutritional counseling and academic tutoring that encourage lifelong health. Plus, they say, it's better than leaving kids at malls and fast-food restaurants.

"What are our teenagers doing when they're idle? They eat, they go to Starbucks, they sit around at the mall and they have corresponding health problems," said CEO Laura Tauscher, a mother of two teenagers. "We're not trying to create gym rats — we're trying to give kids the tools and intelligence to keep their health in mind."

Overtime, which opened in September and still hasn't turned a profit, is entering the market as established chains are trying to get kids to become lifetime members. San Ramon-based 24 Hour Fitness just started "Hoopology," a summer basketball pilot program in the San Francisco Bay Area for boys and girls ages 8-17.

The company is far from the first niche gym — Curves International Inc., which targets women 35 and older, debuted in 1992 and has become the largest fitness franchise in the world, with 10,000 locations in 42 countries. Curves is based in Woodway, Texas. There are about 1.5 Curves for every two McDonald's in the United States.