Tackle obesity...by going online!

A new game aims to combat childhood obesity with virtual reward-based incentives to get young teens off the couch and on the move.

Dubbed Zamzee, the game comes equipped with a hip-worn sensor that tracks kids' movements and awards physical activity with points that they can upload to the Zamzee web portal.

There they can access rewards to buy virtual goods at Zamzee's online store and share their data with their friends in the social network. Its maker, a nonprofit game developer called HopeLab, aims to launch the game this fall, and a spokesperson for the company told Relaxnews that registering for Zamzee will be free but the activity meter should cost in the $50 range.

Hopelab has also created a game for cancer patients called Re-Mission that pits a nanobot named Roxxi against cancer cells. A study of that game published in the journal Pediatrics showed that patients who played Re-Mission were more likely to stick to treatment programs. For Zamzee, Hopelab stated on its website that it has completed a pilot test that found a 30 percent increase in physical activity in the 350 teens who used the device for some 10,000 days.

"Although the idea of a reward-based system is not strictly new for these types of devices, the child centered approach for its design is quite interesting," reported tech site Medgadget on Wednesday. "It is a fascinating project and we will be watching closely to see how it develops."

For grownups and older teens who need a nudge to work out, self-monitoring fitness tools are aplenty. A new app called Nexercise lets you rack up credits for physical activity in exchange for real-world benefits, including gift cards, coupons, and vitamin supplements.

Among other devices for enhanced self-awareness is the FitBit, a small clip-on tracker that monitors your fitness and sleep patterns. Also, the Nike+ monitors heart rate data, calorie burn, pace, and distance of runs and other workouts.