Adolescent girls who live within half a mile of a public park are significantly more physically active than other girls, University of North Carolina at Chapel Hill researchers have found.

The study found that physical activity was higher for girls who lived within a mile of parks and showed highest levels among girls who lived less than one-half mile from a park, said Dr. Diane Catellier, a study investigator and research associate professor of biostatistics in the UNC School of Public Health. The researchers found that girls only got about 114 minutes a week of intense physical activity outside of school hours, or about 16 minutes a day.

Dr. Deborah Cohen, a senior natural scientist at RAND Corporation and lead author of the study, said the U.S. surgeon general recommends that all children and adolescents get at least 60 minutes of exercise a day. 'We still have a long way to go in encouraging girls to be active.'

The results appear in the November 2006 issue of Pediatrics. The study was led by the RAND Corporation, a nonprofit research organization. Researchers from UNC-Chapel Hill, the University of Arizona, the University of South Carolina and San Diego State University participated. Funding was provided by the National Heart, Lung and Blood Institute, part of the National Institutes of Health.

In the wake of growing national concern about increasing rates of obesity and health problems brought about by Americans' diets and sedentary lifestyles, the study findings could have implications for both males and females in other age groups as well, Catellier said.