A new study in Wednesday's Journal of the American Medical Association said that, as kids grow, they cut back dramatically on exercise.
The study followed about 1,000 U.S. children across a spectrum of ages, and its findings have prompted the National Institutes of Health to reiterate its call for greater physical activity among American children.
The federal Dietary Guidelines for Americans recommend that children and adolescents engage in at least 60 minutes of physical activity, seven days a week.
To find out what a healthy weight is for your growing child, check out the Centers for Disease Control and Prevention's body mass index (BMI) chart, especially designed for children.
For more information on BMI and how to interpret your child's percentile, click here.
ABC News' Medical Unit compiled a list of the following organizations that provide resources on how to encourage your kids to get off the couch and get outside.
WE CAN! (Ways to Enhance Children's Activity and Nutrition) is a national education program to help prevent children from becoming overweight or obese. The site offers tips and family activities to encourage healthy eating, increase physical activity, and reduce the time kids spend in front of TV and computer screens. Energy Out Activities charts different ways for parents to think about increasing activity levels.
Empowering Youth is a manual for teacher and youth group use for 11- to 18-year-olds. It offers current nutrition and physical activity information to enhance knowledge, and fun activities to teach nutrition.
Smallstep for Kids is a child-oriented site offering nutritional advice, games and activity suggestions for children and parents, as part of the U.S. Department of Health and Human Service's obesity prevention campaign.
KidsHealth, created by the Nemours Foundation's Center for Children's Health Media, hosts this page that goes over healthy exercise guidelines for kids and teens.
New York Online Access to Health has a great list of resources when it comes to learning more about kids and exercise. Click here.
The President's Challenge throws down the gauntlet to the nation's children, challenging them to attain healthy goals for exercise and activity.