Hey parents, a few words of wisdom from the pros during spring break season: If you're worried that your children have gotten too sedentary, play with them. Shoot hoops, dance around the living room, toss a ball, play tag.

Many exercise experts believe children today don't move around enough, and that is contributing to the childhood obesity epidemic with a third of children weighing too much. The government's physical activity guidelines recommend that children and teens do an hour or more of moderate-intensity to vigorous physical activity daily.

One way to get them to move more is to go out and do things with them so they're having fun, says Robert Malina, professor emeritus at the University of Texas-Austin. Try to work in 20 minutes of activity before or after dinner, he says.

Parents should listen to what their children want to do and then do it with them, he says. "The children will learn from their parents, and the parents will learn from their children. More importantly, they will be together."

Brian Saelens, a children's obesity researcher at Seattle Children's Research Institute, says children mimic their parents' sedentary behavior just like they mimic their physical activity behavior. So if parents are heavy TV watchers, their children tend to be the same. Saelens, who has three children younger than 5, says when he gets home, he doesn't watch TV with his children but dances, runs, wrestles and plays with them.

Parents have to give their children the tools to be active by making sure they have things like balls, Frisbees, jump ropes, hula hoops, says James Sallis, director of the Active Living Research Program at San Diego State University. For those who can afford it, dance video and active video games are options. "Luckily there has been an improvement in active video games," he said.

Play and activity used to happen naturally for children, but over time, unstructured play for children has gone down and structured play has gone up, he says. This is partly due to parental concerns about safety issues, and partly because of cutbacks in recess, gym classes and after-school programs, he says. "So now we've got to work activity back into their lives."