Children and teens who have grown up practically attached to computers like the games. But do they provide much by way of exercise? Many do, say researchers who are now quantifying the workouts. According to two recent studies, some of these so-called exergames can make players huff and puff enough to offer a serious calorie burn.

The findings offer an important alternative strategy for parents, schools and others who care for children as they try to get their charges off the couch and moving.

"Previously we've focused on sports as a way to get children physically active," but not all of them are interested in organized sports, said Bruce Bailey, assistant professor of exercise science at Brigham Young University and lead author of one of the studies. Schools, he added, are trying to make their P.E. classes more inclusive to children of different sizes and interests, and "I think this is one way of doing that."

Active games first came on the scene in the early 2000s with now-classics such as Dance Dance Revolution. The category has since exploded. Today, the offerings are more sophisticated, more challenging and have more-realistic video effects. They are featured on practically every major consumer gaming platform, including the Nintendo Wii, Xbox 360 and PlayStation 3.

In addition, many schools, gyms, community centers and hospitals include stationary bikes with video screens and customizable programs; digital target games that challenge players on speed and motor skills as they throw a ball; and sports simulation games that allow users to feel like they're playing games such as soccer. Some cost as much as $6,000