"Exergaming" is a genre of video game that uses physical activity as input. With its roots in Virtual Reality research of the 1980s, exergaming has become accessible and popular thanks to Nintendo's Wii Sports exercise games such as as tennis, baseball, golf, bowling, and boxing.

Ian Bogost presents an interesting history of exergaming in The Rhetoric of Exergaming. If you're interested in creating exergames, you might take a look at Considerations for the Design of Exergames, by Jeff Sinclair, Philip Hingston, and Martin Masek.

Contributing to exergaming's growing popularity are recent reports like that out of John Hopkins University that predicted that nearly 24 percent of U.S. children and adolescents will be overweight or obese by 2015. As if this isn't bad enough, children with visual impairments face even greater fitness challenges.

"Lack of vision forms a significant barrier to participation in physical activity and consequently children with visual impairments have much higher obesity rates and obesity-related illnesses such as diabetes," says Eelke Folmer, an assistant professor in the computer science and engineering at the University of Nevada, Reno.

Which is why Folmer and his fellow researchers -- Tony Morelli, John Foley, and Lauren Lieberman -- have launched VI Fit, a project designed to help children who are blind become more physically active and healthy through video games such as a motion-sensing-based tennis and bowling exergames that can be downloaded for free at project's website.

"Our games are adaptations of the popular Nintendo Wii Sports exercise games that have been modified so they can be played without visual feedback," Folmer said.

VI Tennis and VI Bowling are the first of several games to be made available. VI Tennis implements the gameplay of Wii sports tennis providing audio and vibrotactile cues that indicate when to serve and when to return the ball. It can be played against the computer or against a friend using two Wii remotes.

The gameplay of Wii sports bowling is implemented through VI Bowling with a novel motor-learning feature that allows players to find the direction in which to throw their ball using vibrotactile feedback. Audio and speech effects are used to indicate the result of each throw. VI Bowling was evaluated with six adults and was found to yield levels of active energy expenditure that are comparable to walking.