Vigorous physical activity among high school students - United States, 1990

Morbidity and Mortality Weekly Report, Jan 24, 1992

Vigorous physical activity can improve the health of both adults and children. Among adults, regular physical activity can reduce risk for chronic diseases such as coronary heart disease, hypertension, noninsulin-dependent diabetes mellitus, colon and depression, as well as lower all-cause death rates (1,2). Among children, cancer regular physical activity can reduce chronic disease risk factors such as obesity, elevated cholesterol, and hypertension (3). Physical activity patterns established during childhood may extend into adulthood (4). This report examines the prevalence of vigorous physical activity among U.S. students in grades 9-12.

The national school-based Youth Risk Behavior Survey (YRBS) is a component of the Youth Risk Behavior Surveillance System, which periodically measures the prevalence of priority health-risk behaviors among youth through representative national, state; and local surveys (5). The 1990 YRBS used a three-stage sample design to obtain a representative sample of 11,631 students in grades 9-12 in the 50 states, the District of Columbia, Puerto Rico, and the Virgin Islands. Students were asked on how many of the 14 days preceding the survey they had had "at least 20 minutes of hard exercise that made you breathe heavily and made your heart beat fast." Students who reported having engaged in this kind of exercise 3 or more days per week were classified as vigorously active. Students also were asked if they had exercised in a sports league, dance class, recreational center, or any other community center during the 14 days preceding the survey; how many hours a day (on an average school day) they watched television and videos during the 14 days preceding the survey; and on how many varsity or junior varsity sports teams they played at school during the 12 months preceding the survey.

Of all students in grades 9-12, 37.0% reported being vigorously active three or more times per week (Table 1). Vigorous activity was significantly less common among female students (24.8%) than among male students 49.6%), among black students (29.2%) than among either white (39.3%) or Hispanic (34.5%) students, and among female students in grades 11 (23.4%) and 12 (17.3%) than among those in grade 9 (30.6%).

For both sexes, students who were vigorously active were significantly more likely to participate on varsity or junior varsity sports teams and to exercise at a community center than were those who were not vigorously active (Table 2). Female students who were vigorously active were significantly less likely to watch television or videos 3 or more hours per day (32.5%) than were female students who were not vigorously active (40.4%).

Reported by: Div of Chronic Disease Control and Community Intervention, Div of Adolescent and School Health, National Center for Chronic Disease Prevention and Health Promotion, CDC.

Editorial Note: A national health objective for the year 2000 (objective 1.4) is to increase to at least 75% the proportion of youth aged 6-17 years who engage in vigorous physical activity that promotes the development of cardiorespiratory fitness (i.e., 3 or more days per week for 20 or more minutes per occasion) (6). Data in this report indicate that current levels of vigorous physical activity among high school students will have to more than double to reach this objective.

Moreover, findings in this report suggest that participation in vigorous physical activity among high school students may be decreasing. The National Children and Youth Fitness Study conducted in 1984 showed that 61.7% of students in grades 10-12 participated in vigorous physical activity for 20 or more minutes 3 or more days per week (7); only 36.1% of students in grades 10-12 reported doing so in the current report. Participation in school physical education also may be decreasing (8).

Race/ethnicity- and sex-specific differences described in this report are consistent with patterns of physical activity observed among adults (9). Lower levels of physical activity characteristic of black adults and adult females of all races may be manifest by grade 9. Interventions to increase physical activity among persons in the United States need to target school-aged youth to help reverse declining levels of physical activity and break patterns of sedentary living. School physical education, sports teams, and community recreation centers should be used to help promote lifelong physical activity 6,8). Educators, families, physicians, and public health officials need to establish policies and programs that help increase access to physical activity facilities for youth and encourage youth to participate regularly in vigorous physical activity (6).

References

1. Powell KE, Caspersen CJ, Koplan JK, Ford ES. Physical activity and chronic diseases. Am J Clin Nutr 1989;49:999-1006.

2. Paffenbarger RS Jr, Hyde RT, Wing AL, Hsieh CC. Physical activity, all-cause mortality, and longevity of college alumni. N Engl J Med 1986;314:605-13.