Video games aimed at getting kids to move their rumps don’t actually work, a new study from Baylor College of Medicine finds.

The study tapped 78 healthy nine- to twelve-year-old children of above-average weight, gave them “active” video games (think Dance Dance Revolution and Wii Sports rather than Mario Kart) and had them wear pedometers and record a log of their physical activity for a twelve-week period.

“The researchers expected a big spike in activity,” NPR’s Nancy Shute wrote. “But much to their surprise they found no increase in running, jumping and swinging during the 12-week experiment, compared to the children who got typical only-my-thumbs-are-moving video games.”

The news comes as a disappointment for public health officials, who have hoped that playing such video games will lead to more active lifestyles.

“We expected that playing the video games would in fact lead to a substantial increase in physical activity in the children,” Tom Baranowski, the Baylor College of Medicine pediatrics professor who led the study, told Reuters Health. “Frankly we were shocked by the complete lack of difference.”