title: Examination of adolescents' screen time and physical fitness as independent correlates of weight status and blood pressure.
abstract: Physical fitness performance is an important health correlate yet is often unrelated to sedentary behaviour in early adolescence. In this study, we examined the association of sedentary behaviour (i.e. screen time) with weight-related health markers and blood pressure, after controlling for cardiorespiratory fitness performance. American middle school students (N = 153, 56% females) aged 11-15 years (mean 12.6 years, s = 0.5) completed assessments of cardiorespiratory fitness performance, screen time, weight status (BMI percentile, waist-to-height ratio), and blood pressure. Multivariate analysis of covariance, controlling for cardiorespiratory fitness performance, found those who met the daily recommendation of 2 h or less of screen time (n = 36, 23.5%) had significantly lower BMI (p < 0.05) and systolic blood pressure (p < 0.01) compared with those who exceeded this recommendation. Findings suggest specific intervention programmes may be designed to target both cardiorespiratory fitness and sedentary behaviours to maximize early adolescent health because these behaviours are likely to have unique and independent effects on youth health markers.
authors.affiliation: Educational Leadership and Counselling Psychology, Washington State University, Pullman, Washington 99164-1410, USA. sullrich@wsu.edu
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Ullrich-French
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Power
authors.forename: Kenn B
authors.initials: KB
authors.lastname: Daratha
authors.forename: Ruth C
authors.initials: RC
authors.lastname: Bindler
authors.forename: Michael M
authors.initials: MM
authors.lastname: Steele
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D015415:Biomarkers; D001794:Blood Pressure; D015992:Body Mass Index; D002319:Cardiovascular System; D002648:Child; D003201:Computers / Q000706:statistics & numerical data*; D005080:Exercise Test; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D010809:Physical Fitness; D012137:Respiratory System; D057185:Sedentary Behavior; D013690:Television / Q000706:statistics & numerical data*; D014481:United States
chemical_list: D015415:Biomarkers