Press Releases

2000 Releases

Children Are Less Active Than They Think

For immediate release: May 14, 2000 

Boston, MA--In a study by Harvard School of Public Health (HSPH) researchers, children demonstrated a misperception of their physical activity, estimating that they had engaged in one hour of vigorous activity the previous day when, in fact, they had only spent about two minutes playing vigorously. The research results have import for parents and health practitioners trying to get children to engage in significant exercise--a difficult challenge if the children believe they already are exercising enough.

The researchers used sophisticated motion recorders to track amounts and intensities of physical activities in a group of children aged 11 to 13 years old. They then compared the electronic data to the children's own reports of their own physical activity and found glaring discrepancies.

The motion recorders, called accelerometers, are devices the size of small cassette players that are worn on a waist belt and count the body's movements in any activity.

"There are several implications for children overestimating their times and amounts of activity," said Angie Cradock, lead researcher and doctoral student at HSPH. "If children--or adults--hear a recommendation that they should be engaging in 30 minutes of moderate or vigorous activity per day, and they believe that they're already beyond that level, then they might ignore the recommendation. The truth may be that they are getting much less than the recommended amount of exercise. These findings also emphasize the need for better ways for youth and adults to accurately assess their own activity levels."

Accurate measurements of activity levels are also a prerequisite to sound research on health effects of exercise and for evaluating the effectiveness of programs designed to increase the activity levels of children.

Forty-five children participated in the study, agreeing to both wear the accelerometers and to answer questions about the duration and intensity of physical activity in the previous 24 hours. Sedentary and very light activities included sleeping, watching television, and playing video games. Moderate activities included yard work, climbing trees, and skateboarding.

Children not only overestimated their vigorous activities, but also the time they spent in moderate activity.

The accelerometers and the children did agree on one category of activity. Steven Gortmaker, faculty member at HSPH and co-author, said that both sources reported that the children spent an average of about ten hours engaged in sedentary or very light activities.

This research will be presented at the Pediatric Academic Societies and the American Academy of Pediatrics Joint Meeting in Boston, Massachusetts, on May 14. The conference runs May 12--16.

For further information, please contact:

Robin Herman
Director of Communications
677 Huntington Avenue
Boston, Massachusetts 02115
Phone: 617-432-4752
Email: rherman@hsph.harvard.edu