They're furry, fun loving and could be the key to getting your sedentary teen off the couch, finds a new study on dog ownership and adolescent physical activity.

"You can think of your dog not only as your best friend, but also a social support tool for being active," said John Sirard, Ph.D., the study's lead author and an assistant professor at the University of Virginia in Charlottesville.

In the study, which appears in the March issue of the American Journal of Preventive Medicine, Sirard and his colleagues surveyed 618 pairs of Minneapolis adolescents and their parents about the number of dogs in their home and how much time they spent in physical activity. For a week, 318 of those teens also wore accelerometers - devices used to collect data on time spent moving.

It turns out that teens from dog-owning families recorded greater amounts of movement on the accelerometer devices, even after researchers took into account demographic variables, like gender, race and socioeconomic status.

That might mean that teens with dogs could log about 15 additional minutes of moderate to vigorous physical activity per week, according to the authors.

The association with adolescent physical activity took the researchers by surprise. They expected that if anyone in the family were to walk the dog, it would be the parents. "If dog ownership has an effect, we hypothesized it would have an effect on adults, but we didn't see that. We saw it in the kids," Sirard said.

Finding ways to encourage teens' physical activity levels is critical, since time spent exercising drops precipitously after the elementary school years, said Cheryl B. Anderson, Ph.D., a visiting assistant professor of pediatrics at the Children's Nutrition Research Center at Baylor College of Medicine.

Despite the link that researchers established between dog ownership and teenagers' physical activity, they said they could not be certain that getting a dog means people will be more active. "It might be that more active people choose to get dogs because it fits their lifestyle already," Sirard said.

"You may walk it, you may not, but the fact that you have this animal in the house makes you get up off the chair more. Every bit of activity is important," Anderson said.

Sirard JR, et al. Dog ownership and adolescent physical activity. Am J Prev Med 40(3), 2011.

Health Behavior News Service