Kids should use TVs for fitness by playing "exergames" on their Wii or other consoles. But when they're done, turn the things off! That is my over-simplified mash-up of two new studies in the medical journal Pediatrics.

One, which was based on surveys of teenagers in Montreal, Quebec, found that relatively active video games such as Wii Sports and Dance Dance Revolution legitimately add to kids' weekly exercise routines. A second study, surveying the parents of U.S. children, reported that children receive 232 minutes of background television exposure every day. The findings were "startling," the authors reported, because there is growing research that this background noise can interfere with child development and health.