US researchers are exploring how interactive digital games could be better designed to improve players' health.

The University of North Carolina at Chapel Hill School of Public Health has received a grant from the Robert Wood Johnson Foundation to carry out the study.

"Research shows that young adults play video games as much as, or in some cases more than, children," said Deborah Tate, assistant professor in Chapel Hill School's Department of Health Behaviour.

"Since young adulthood is a time of decreasing physical activity and rapid weight gain, video games may provide a more active form of leisure than traditional TV for this age group."

Tate and doctoral student Elizabeth Lyons will investigate the motivation to expend energy while playing video games.

They will compare traditional video games played on home consoles, which use a hand-held or motion-sensing controller, with more active games requiring physical movement beyond pushing buttons or flicking the wrist.

These active games require players to use a controller such as a dance pad, balance board or even a guitar.

"The research focuses on presence and intrinsic motivation. Presence is the perception of actually being in the game environment. Intrinsic motivation is the desire to do something for its own sake and not for a reward," said Lyons.

"Both presence and intrinsic motivation seem to increase the amount of time players spend with games.

"But these two factors have never been measured or studied to assess their impact on the amount of energy people will expend when playing an active game or when playing a traditional game."