Age-Related Change in Physical Activity in Adolescent Girls

• Published in: Journal of adolescent health Vol. 44; no. 3; pp. 275 - 282
• Main Authors: Pate, Russell R., Ph.D, Stevens, June, Ph.D, Webber, Larry S., Ph.D, Dowda, Marsha, P.H, Murray, David M., Ph.D, Young, Deborah R., Ph.D, Going, Scott, Ph.D
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.03.2009; Elsevier
• Subjects: Acceleration; Accelerometry; Adolescent; Adolescent girls; Adolescents; Age Factors; Biological and medical sciences; Body Mass Index; Cross-Sectional Studies; Developmental psychology; Exercise; Female; Fundamental and applied biological sciences. Psychology; Girls; Humans; Middle school; Middle schools; Monitoring, Physiologic - instrumentation; Pediatrics; Physical activity; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Self Disclosure; United States; United States; North America; America; Physical activity; Adolescents; Middle school; Girls; Accelerometry; Human; Physical exercise; Behavior change; Latinamerican; Ethnic group; School environment; Adolescent; Female; Caucasoid; Age; African American
• ISSN: 1054-139X; 1879-1972
• DOI: 10.1016/j.jadohealth.2008.07.003

Abstract Purpose To determine the annual rate at which physical activity changes in girls during middle school using both objective and self-report measures of physical activity. Methods Participants were sixth- and eighth-grade girls from the control schools in the Trial of Activity for Adolescent Girls (TAAG). Random cross-sectional samples initially were drawn from sixth-grade girls (n = 786) and 2 years later from eighth-grade girls (n = 1545). A cohort of 501 girls was in both the sixth- and the eighth-grade samples. The girls wore an accelerometer for 6 days and completed the 3-Day Physical Activity Recall. Data were summarized using 3.0-, 4.6-, and 6.5-metabolic equivalent cutpoints for accelerometry and self-reported physical activity. Analyses were performed using repeated-measures analysis of variance in PROC MIXED. Results More than 40% of the girls were white, approximately 20% were African American, and 20% were Hispanic. The annual percent decrease in physical activity in the cross-sectional sample was approximately 4% (−1.76 min moderate-to-vigorous physical activity/day), using accelerometer data. The percent decrease in physical activity based on self-report data was higher, 6% to 13%, depending on the physical activity variable. Declines tended to be larger in African American girls, but the ethnic differences were not statistically significant. Conclusions Based on comparisons of cross-sectional samples of sixth- and eighth-grade girls, objectively measured physical activity declined at a rate of 4% per year.