School-age children should participate in 60 minutes or more of moderate to vigorous physical activity daily, according to an expert panel.
"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," says Dr. William B. Strong, a pediatric cardiologist and retired professor at the Medical College of Georgia who co-chaired the panel.
"The important thing is we have to get American children and adolescents active," says co-chair Dr. Robert M. Malina, research professor and an expert in growth and development at Tarleton State University in Stephenville, Texas. "The evidence is very clear that physical activity has decreased dramatically in the last 10 to 20 years," Dr. Malina says as the technology revolution of the 1980s produced more sedentary options for children while their caloric intake has essentially remained the same.
"Our children are just not burning up those calories today," Dr. Malina says of the obesity epidemic in children. "All of us need to help children increase the amount of time spent in moderate to vigorous physical activity. This means that parents, coaches, teachers and others who influence youngsters need to become active role models and get children involved with regular participation in physical activity."
"Increasing the level of habitual moderate to vigorous intensity physical activity in youth is a health promotion and a disease prevention strategy," the panelists conclude. Restoration of physical education and other school- and community-based programs could contribute mightily to that strategy, they say.
Recommendations of the 13-member panel are published in the June issue of The Journal of Pediatrics. Panelists were convened by the Constella Group, Inc., a professional health services company headquartered in Durham, N.C., contracted by the Divisions of Nutrition and Physical Activity and Adolescent and School Health of the Centers for Disease Control and Prevention.
"We were asked to review the literature and find evidence of the impact of physical activity on the health and well-being of children and to make recommendations based on the evidence, not just on what we all believe to be beneficial," says Dr. Strong, Charbonnier Professor Emeritus at MCG and founding director of MCG's Georgia Prevention Institute, where researchers are exploring issues such as the impact of activity on children's weight and cardiovascular health.
The hope is that the evidence-based recommendations will be taken to heart by children, parents and schools as well as an elite list of organizations that impact children's health, including the American Academy of Pediatrics, the American Heart Association, the National Association for Sport and Physical Education, the Robert Wood Johnson Foundation, and the U.S. Department of Health and Human Services. Representatives of those groups attended the January 2004 meeting of the expert panel.
Panelists reviewed more than 850 articles and 1,200 abstracts looking at the impact of physical activity on a wide range of health factors from body fat to lipid levels to how children perceive themselves.
Most of the studies in the literature had children performing 30 to 45 minutes of continuous moderate to vigorous physical activity three to five days per week. To achieve similar or greater benefits in the context of typically intermittent, ordinary daily activities would require a cumulative time of an hour or more, the experts write.
Jumping rope, soccer, basketball, and brisk walking are all examples of moderate to vigorous physical activity, Dr. Strong says, noting that sedentary children need to increase activity gradually. "Youngsters tend to get bored easily so they have to have variety," says Dr. Malina, who has doctoral degrees in both physical education and anthropology. "In addition, youngsters like physical activities that are challenging."
Experts say much of the needed activity can be achieved at school with appropriate physical education, recess, intramural sports and before- and after-school programs. "In this regard, CDC recommends daily quality physical education from kindergarten through grade 12," the panelists write. "Both physical education and recess afford opportunities to achieve the daily physical activity goal without any evidence of compromising academic performance…. Restoration of intramural sport programs and expansion of the school day for such programs in middle and high schools may provide opportunities for all students to be physically active."
"We need to educate teachers and administrators that physical education is important for youngsters," says Dr. Malina, noting that historically when concerns about progress in math and science emerge, physical education and art get moved aside. "The evidence is clear, a renewed emphasis on physical activity in our schools will not have a negative impact on academics," he says.
The recommendations are reasonable and achievable by most children with some effort, the experts say. Parents, pediatricians, daycare centers, and preschools also play important roles in encouraging healthy behaviors, panelists say. Communities can as well by providing safe, appropriate settings such as bike paths and green space, they say.
And if an hour is good, is more even better? "I don't think there is any question that more is better within limits," Dr. Strong says, noting again the importance of the recommendations being based on available science.
Other panelists and authors include Dr. Cameron J.R. Blimkie, McMaster University, Ontario; Dr. Stephen R. Daniels, Children's Hospital Medical Center, Cincinnati; Dr. Rodney K. Dishman, University of Georgia; Dr. Bernard Gutin, MCG; Dr. Albert C. Hergenroeder, Baylor College of Medicine; Dr. Aviva Must, Tufts University School of Medicine; Dr. Patricia A. Nixon, Wake Forest University; Dr. James M. Pivarnik, Michigan State University; Dr. Thomas Rowland, Baystate Medical Center in Springfield, Mass.; Dr. Stewart Trost, Kansas State University; and Dr. Francois Trudeau, Universite du Quebec a Trois-Rivieres, Quebec.