Getting our sedentary, overweight children off the couch is a challenge. That’s why the Nintendo Wii game console, which arrived in the United States six years ago, was such an exciting prospect. It offered the chance for children to get exercise without even leaving the house.

Tennis was one of the games in the Wii Sports software that came in the box with the console. This was the progenitor of “exergames,” video games that led to hopes that fitness could turn into irresistible fun.

But exergames turn out to be much digital ado about nothing, at least as far as measurable health benefits for children. “Active” video games distributed to homes with children do not produce the increase in physical activity that naive parents (like me) expected. That’s according to a study undertaken by the Children’s Nutrition Research Center at Baylor College of Medicine in Houston, and published early this year in Pediatrics, the official journal of the American Academy of Pediatrics.

Previous studies have shown that adults and children who play active video games, when encouraged in an ideal laboratory setting, engage in moderate, even vigorous physical activity briefly. The Baylor team wanted to determine what happened when the games were used not in a laboratory, but in actual homes.

The participants in this study were children 9 to 12 years old who had a body mass index above the median and whose households did not already have a video game console. Each was given a Wii. Half were randomly assigned to a group that could choose two among the five most physically demanding games that could be found: Active Life: Extreme Challenge; EA Sports Active; Dance Dance Revolution; Wii Fit Plus; and Wii Sports. The other half could choose among the most popular games that are played passively, like Disney Sing It: Pop Hits and Madden NFL 10.

The participants agreed to wear accelerometers periodically to measure physical activity over the 13-week experiment. To observe how well the intrinsic appeal of active games changed children’s behavior, the researchers distributed the consoles and games without exhortations to exercise frequently.

They found “no evidence that children receiving the active video games were more active in general, or at any time, than children receiving the inactive video games.”

How is it possible that children who play active video games do not emerge well ahead in physical activity? One of the authors of the Pediatrics article, Anthony Barnett, an exercise physiologist who is a consultant at the University of Hong Kong, explains that the phenomenon is well known in the field.

“When you prescribe increased physical activity, overall activity remains the same because the subjects compensate by reducing other physical activities during the day,” he says.