School-age children should engage in at least 60 minute's worth of moderate or vigorous physical activity each day, a panel of experts recommends.

"The important thing is we have to get American children and adolescents active," Dr. Robert M. Malina, a co-chair of the panel, said in a press release. "The evidence is very clear that physical activity has decreased dramatically in the last 10 to 20 years," said Malina, who is at Tarleton State University in Stephenville, Texas.

The Divisions of Nutrition and Physical Activity and Adolescent and School Health of the Centers for Disease Control and Prevention contracted with the Constella Group, a North Carolina-based health-services company to convene the panel of 13 experts.

The panel's recommendations, which are published in the Journal of Pediatrics, are certainly not the first time that health experts have issued a call for American children to get more physical activity. When the panelists reviewed more than 850 studies on physical activity in children, they found that many studies showed that 30 to 45 minutes of moderate to vigorous exercise 3 to 5 days a week can boost children's health.

The panel notes that most of these studies examined the effect of 30 to 45 minutes of continuous exercise. In real life, children are more likely to engage in shorter bouts of physical activity throughout the day.

So to get the health benefits they need, the experts recommend that children should set a daily goal of at least an hour of physical activity, not necessarily all at once.

"The take-home message for parents is that it is very important to ensure that their children spend at least an hour a day in some form of appropriate physical activity," panel co-chair Dr. William B. Strong, retired from the Medical College of Georgia in Augusta, said in a press release.

But parents shouldn't think they have to send their six-year-old off to the gym to run on a treadmill for an hour each day. Children can get the physical activity they need throughout the day during physical education class, school recess, sports and before- and after-school play.

Although most children should be able to meet the recommendations, the panel advises that sedentary children ease into physical activity. For these children, a good rule of thumb is to increase activity by 10 percent per week, according to the panel.

SOURCE: Journal of Pediatrics, June 2005.