Children who play active video games don't actually exercise enough at home to gain any benefit compared with regular video games, a new study finds.

Active video games like Dance Dance Revolution and Wii Fit Plus are marketed with the suggestion children will burn more calories than they would sitting down to watch TV or playing a traditional video game.

Some public health researchers hoped the active games might provide an alternative to playing sports and outdoor games, or offer physical activity for children in neighbourhoods where playing outside isn't always a safe option.

Lab studies suggest the active games can work, but what happens in real life?

To find out, Tom Baranowski, a professor of pediatrics at Baylor College of Medicine in Houston and his team randomly assigned 78 children between the ages of nine and 12 to a new Wii video game console with either active games or inactive games.

The children were free to chose the game they wanted at the start of the study and a new one of the same type after six weeks.

Each child wore an accelerometer on a belt at the waist to track movement for five weeks over the 13-week experiment. They were all above-average weight when measured.

"There was no evidence that children receiving two active video games and the peripherals necessary to run them were any more active over a 12-week period than those who received two inactive video games," the study's authors concluded.

Although children in the lab studies generated moderate physical activity, they either chose not to play the games that intensely on their own or they compensated for the increased intensity by moving less at other times of the day, the researchers said.

Given the findings, there is no reason to believe that active games offer a public health benefit to children, they said.

Canadian health authorities recommend that children aged five to 11 get at least 60 minutes of moderate to vigorous physical activity a day, such as skipping, riding a bike or playing tag.