But beyond whatever effects media may have, she said, children who spend their free time on the couch miss out on the socialization, team work and skill development that comes with being active.
Among the nearly 12,000 middle- and high-school students in her study, those who were physically active were less likely than their couch-potato peers to smoke, drink, use drugs or have sex. Also, they often had higher self-esteem and better grades.
"Across the board, children who engaged in any kind of activity were better off than kids who watched a lot of TV." said Gordon-Larsen.
The findings, which are published in Pediatrics, also show that activity does not simply mean traditional sports.
Kids who favored "alternative" activities, like skateboarding, had higher self-esteem and were less prone to taking health risks, Gordon-Larsen pointed out.
The bottom line for parents, according to the researcher, is that they should encourage their kids to pursue whatever physical activities they happen to enjoy.
If mom and dad can handle a skateboard themselves, even better. Teens in the study who engaged in sports and exercise with their parents were particularly likely to stay on the straight and narrow.
