Physical Activity Levels Among Children Aged 9--13 Years --- United States, 2002

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Three national health objectives for 2010 (objectives no. 22-6, 22-7, and 22-11) aim to increase levels of physical activity and reduce sedentary behavior among children and adolescents (1). To promote a healthy, more active lifestyle among U.S. youth, CDC developed the Youth Media Campaign (YMC), a national initiative to encourage children aged 9--13 years to engage in and maintain high levels of regular physical activity. To provide a baseline assessment of physical activity levels among children aged 9--13 years, CDC conducted the YMC Longitudinal Survey (YMCLS), a nationally representative survey of children aged 9--13 years and their parents. This report presents data from the survey, which indicate that 61.5% of children aged 9--13 years do not participate in any organized physical activity during their nonschool hours and that 22.6% do not engage in any free-time physical activity. Improving levels of physical activity among this population will require innovative solutions that motivate children and that address parents' perceived barriers to their children engaging in physical activity.

YMCLS is a national, random-digit--dialed telephone survey of children aged 9--13 years and their parents. CDC surveyed approximately 4,500 child/parent dyads living in approximately 3,600 households; 3,120 child/parent dyads (representing 87.0% of eligible adult respondents and 81.3% of eligible child respondents) completed a survey*. Data were adjusted for parent and child nonresponses and standardized to decennial census estimates of children's race/ethnicity, age, and sex. WesVarPC software was used to calculate point estimates and 95% confidence intervals (2). Data on race/ethnicity were analyzed only for non-Hispanic black, non-Hispanic white, and Hispanic children aged 9--13 years because numbers for other racial/ethnic populations were too small for meaningful analysis. T-tests were conducted when appropriate by using a Bonferoni adjustment to identify statistically significant differences among subpopulations.

Participation in an organized physical activity was defined as self-reported participation during the 7 days preceding the survey in a physical activity "with an organized group that has a coach, instructor, or leader." Participation in free-time physical activity was defined as self-reported engagement during the 7 days preceding the survey in a free-time physical activity. Participation in both after-school and weekend physical activities was included; participation in activities engaged in during the school day was excluded. Parents were asked about their perceptions of five potential barriers to their children's participation in physical activities: transportation problems, lack of opportunities to participate in physical activities in their area, expense, parents' lack of time, and concerns about neighborhood safety.

Fewer children aged 9--13 years reported involvement in organized sports (38.5%) than in free-time physical activity (77.4%) during the 7 days preceding the survey (Table 1). Non-Hispanic black and Hispanic children were significantly less likely (p<0.05) than non-Hispanic white children to report involvement in organized activities, as were children with parents who had lower incomes and education levels.

Although parents generally perceived the same barriers to participation in physical activities regardless of the child's sex and age, concerns about transportation, opportunities in their area, and expense were reported significantly more often (p<0.05) by non-Hispanic black and Hispanic parents than by non-Hispanic white parents (Table 2). Concerns about neighborhood safety were reported more frequently for girls (17.6%) than for boys (14.6%) and were reported more frequently by Hispanic parents (41.2%) than by non-Hispanic white (8.5%) and non-Hispanic black (13.3%) parents. Overall, parents with lower incomes and education levels reported more barriers.

Regardless of race/ethnicity, age, and sex, the three organized physical activities engaged in most often by children aged 9--13 years were baseball/softball, soccer, and basketball. Among children aged 12--13 years, basketball was mentioned most often by non-Hispanic black girls and boys, soccer was mentioned most often by Hispanic girls and boys, and baseball/softball was mentioned most often by non-Hispanic white girls and boys. Among children aged 9--11 years, dance was among the three activities mentioned most often by non-Hispanic black and white girls, and baseball/softball and soccer were mentioned most often by Hispanic boys. Overall, regardless of age or sex, children reported that their most frequent free-time activities were riding bicycles and playing basketball. Basketball was the only activity that was reported frequently for both organized and free time. Bicycle riding was reported more frequently by children aged 9--11 years, and basketball was the most common free-time activity among children aged 12--13 years. Other activities engaged in frequently during free time were walking and playing active games (reported by girls), playing football (reported by boys), and running and playing active games (reported by girls and boys).

Reported by: J Duke, PhD, Westat, Rockville, Maryland. M Huhman, PhD, C Heitzler, MPH, Youth Media Campaign, National Center for Chronic Disease Prevention and Health Promotion, CDC.

Editorial Note:

The findings in this report constitute the first nationally representative information about levels and types of physical activity among children aged 9--13 years. The findings indicate that although the majority of children aged 9--13 years engage in some level of free-time physical activity, increased rates of participation in both free-time and organized physical activities are needed, especially for non-Hispanic black and Hispanic children.

Insufficient physical activity is a risk factor for persons being overweight or obese and for having many related chronic diseases (3), and regular physical activity is associated with immediate and long-term health benefits (e.g., weight control, lower blood pressure, improved cardiorespiratory function, and enhanced psychological well-being) (4--5). Active children are more likely to become active adults (6), but as many children age into adolescence, their physical activity levels decline (7--8).

The findings in this report are subject to at least five limitations. First, YMCLS is a telephone survey and does not include U.S. households without telephone service. Second, data were self-reported and subject to error, including respondent over-reporting of socially desirable responses. Third, because data were weighted to the national population of children aged 9--13 years as the main unit of analysis, parent estimates might not represent precisely the national population of parents. Fourth, because the survey was conducted during April--June, the activities reported might reflect seasonal participation in certain sports. Finally, duration of physical activity could not be measured because children aged <10 years are unable to aggregate minutes of physical activity accurately over several days.

Although the primary purpose of the data collection described in this report was to establish a baseline level of physical activity among children aged 9--13 years, these data can help public health agencies and community organizations assess current and future needs of middle school children and plan physical activity programs and interventions. The survey findings demonstrate a need to address common barriers to participation in organized physical activities among children, especially members of certain racial/ethnic populations.

Participation in an organized sport probably will result in a meaningful increase in time spent in physical activity. However, socioeconomic barriers that might impede participation in organized sports do not exist for free-time play. For this reason, current promotional efforts focus on increasing free-time physical activity. In October 2002, CDC initiated a media campaign, VERB It's what you do, a 5-year effort to promote physical activity through research, media, partnership, and community efforts. VERB advertisements aimed at children portray physical activity as being "cool," fun, and socially appealing; advertisements aimed at parents encourage them to engage in physical activity with their children and suggest ways to overcome perceived barriers to physical activity. VERB partnership efforts address other issues, including the need to ensure access to safe and affordable physical activity opportunities, both free-time and organized. Information about the VERB campaign is available at http://www.cdc.gov/verb. Additional information about VERB is available at http://www.verbnow.com (for children) and at http://www.verbparents.com (for parents). Information about receiving regular e-mail updates about VERB is available at http://www.cdc.gov/youthcampaign/working_together/index.htm.

References

* Of the 48,675 households sampled, persons in 29,444 (60.5%) households completed the screening interview. Of 3,543 eligible adult respondents, 3,084 (87.0%) completed the parent interview, and of 3,840 eligible child respondents, 3,120 (81.3%) completed the child interview. The overall response rate, 42.8%, is the product of the completion rate for the screening, parent, and child interviews.

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