SACRAMENTO, Calif. -- The movement started with Dance Dance Revolution, a video game that inspired youngsters to give up their joysticks and boogie with abandon in front of the television.

Electronic-toy makers, often denounced for fostering laziness, have discovered that fitness sells.

Some are creating products that encourage children to pursue exercise while indulging their appetite for couch-potato entertainment.

One of the latest: The Smart Cycle, a stationary bike from Fisher-Price for 3- to 5-year-olds, combines pedal power with educational video games.

Coming soon: miniature treadmills and pedometers for preschoolers.

Even the catalog company Back to Basics Toys, which sells classics such as pogo sticks and tumbling mats, will pitch a $55 item called "Get Off the Couch," with interactive games for age 5 and older.

"For better or worse, this is the future," said Jim Silver, editor of Toy Wishes Magazine. "It's your computer, TV and video system, and that is the road we are heading down."

Critics suggest that such electronic toys hardly address the obesity epidemic and might do more to promote sloth than fitness.

"These toys will not change childhood obesity or change lifestyle patterns," said Marianne Szymanski, founder and president of Toy Tip s, a consumer publication that rates toys on four developmental skills: movement, thinking, personality and interaction.

"Sitting on a stationary bike playing video games might give a child a few extra calories to burn but still encourages the problem to begin with."

What isn't debated is the public-health challenge: During the past 30 years, obesity rates among American preschoolers and adolescents have more than doubled -- and more than tripled for children 6 to 11.

The phenomenon is complex, but cutbacks in school physical-education programs and parental fears of letting children run, jump and ride bikes outside the home have played a role.

Experts say the explosion of video games, which can keep children inactively enthralled for hours, hasn't helped.

Fisher-Price developed the $100 Smart Cycle to combine learning with physical activity, according to marketing director Shehnaz Safiuddin.

With Smart Cycle, kids pedal the bike, watch television and steer to maneuver around letters and numbers flashing on the screen. The toy includes a joystick option so the child can stop pedaling and play games without getting tired.

Many parents, Safiuddin said, like the idea of a toy that keeps kids occupied.

"This is not intended at all to replace the outdoor running around in the backyard, hitting the ball or riding your bike down the sidewalk," Safiuddin said. "There are different benefits to different types of play."

Szymanski, who tested the Smart Cycle, recognizes its potential as a hit with kids, but the toy won't earn her top grade.

"It's a great option to a video game or any TV show," she said. "But with the money you are spending, think how many packs of crayons, chalk and Play-Doh you could get.

"Where is the imagination?"

Fitness-oriented video toys aren't entirely new. Japanese video maker Konami introduced Dance Dance Revolution in 1998 and has since created dozens of versions.

The dance pad is a big hit in schools nationwide, particularly in West Virginia, where it is being phased in as part of the state's school fitness programs.

Smaller companies are also getting into the act.

At Back to Basics Toys, General Manager Ken Moe said his company has turned down many products for his popular catalog business because they fail to promote creativity or lifelong social skills.

But he couldn't resist Get off the Couch Interactive, a new virtual toy by Enviro-Mental Toy Co., for kids 5 and older that lets them swing a bat or throw a punch "in a healthy and safe environment."

"My heart rate went up when I tried it, so we think it was going in the right direction," Moe said.

The toy is a less sophisticated version of Nintendo's Wii system, which allows players to get sweaty whacking at virtual tennis balls and rolling a digital bowling ball.

Next year, the company will launch Wii Fit, a wireless game designed for all ages that measures body-mass index and instructs players in aerobics, yoga, stretches and, yes, hula-hooping.

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