title: Sedentary activity and body composition of middle school girls: the trial of activity for adolescent girls.
abstract: This study describes the relationships between sedentary activity and body composition in 1,458 sixth-grade girls from 36 middle schools across the United States. Multivariate associations between sedentary activity and body composition were examined with regression analyses using general linear mixed models. Mean age, body mass index, and percentage of body fat were 12.0 +/- 0.51, 21.1 kg/m2 +/- 4.8, 28.5 +/- 8.9, respectively. Girls averaged 7.7 +/- 1.2 sedentary hours per day and about 13 hr (approximately 97% of the day) of both sedentary and light activities. Overweight girls were significantly more (13 min; p < .003) sedentary, especially after school (> 2 p.m.; p < .01), and less physically active (p < .0001) than normal weight girls. The study documents small but significant associations between sedentary activity and adiposity.
authors.affiliation: National Heart, Lung, and Blood Institute, Bethesda, MD, USA. prattc@nhlbi.nih.gov
authors.forename: Charlotte
authors.initials: C
authors.lastname: Pratt
authors.forename: Larry S
authors.initials: LS
authors.lastname: Webber
authors.forename: Chris D
authors.initials: CD
authors.lastname: Baggett
authors.forename: Dianne
authors.initials: D
authors.lastname: Ward
authors.forename: Russell R
authors.initials: RR
authors.lastname: Pate
authors.forename: David
authors.initials: D
authors.lastname: Murray
authors.forename: Timothy
authors.initials: T
authors.lastname: Lohman
authors.forename: Leslie
authors.initials: L
authors.lastname: Lytle
authors.forename: John P
authors.initials: JP
authors.lastname: Elder
mesh_terms: D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D012044:Regression Analysis; D011795:Surveys and Questionnaires