The mediating role of physical self-concept on relations between biological maturity status and physical activity in adolescent females

The current study examined the mediating role of physical self-concept on relations between biological maturity status and self-reported physical activity in adolescent British females. Biological maturity status, physical self-concept and physical activity were assessed in 407 female British year 7-9 pupils (M age = 13.2 years, SD = 1.0). Participants completed the Physical Activity Questionnaire for Adolescents (Kowalski, Crocker, & Donen, 2004) and the Children and Youth Physical Self-Perceptions Profile (Whitehead, 1995). Percentage of predicted adult height attained at measurement was used as an estimate of biological maturity status. Structural equation modelling using maximum likelihood estimation and bootstrapping procedures revealed that perceptions of sports competence, body attractiveness and physical self-worth mediated an inverse relation between maturity status and physical activity. The results provide partial support for Petersen and Taylor's (1980) Mediated Effects Model of Psychological and Behavioural Adaptation to Puberty within the context of physical activity

Additional file 3: of Adiposity and the isotemporal substitution of physical activity, sedentary time and sleep among school-aged children: a compositional data analysis approach

Mean Daily Behaviour Composition Across zBMI Categories (PDF 93 kb

Additional file 1: of Adiposity and the isotemporal substitution of physical activity, sedentary time and sleep among school-aged children: a compositional data analysis approach

Compositional Data Analysis Description and Sample R Code (PDF 2113 kb

Additional file 2: of Socioeconomic status and dietary patterns in children from around the world: different associations by levels of country human development?

Appendix S3. Ethics Boards Approvals for each of the 12 ISCOLE sites. (DOC 23 kb

Parental factors associated with child meeting WHO MVPA guidelines.

<p>Parental factors associated with child meeting WHO MVPA guidelines.</p

Household coexistence of parental and child overweight.

<p>Household coexistence of parental and child overweight.</p

Parental factors associated with child overweight.

<p>Parental factors associated with child overweight.</p

Mean total sedentary time (SED) and screen time (ST) score.

<p>Mean accelerometer measured SED (Panel A) and self-reported ST (Panel B) for boys (light grey bars), and girls (white bars). Black bars (boys) and dark grey bars (girls) represent overall sample means. Panel A: Accelerometer measured total sedentary time (SED) (hours/day) across all 12 ISCOLE sites (*indicates sites where girls engaged in significantly more SED than boys, p<0.05). Panel B: Self-reported screen time (ST) score across all 12 ISCOLE country sites (in all sites boys had significantly higher values for ST than girls, p<0.05).</p

Descriptive characteristics of all participants (<i>n</i> = 5,844).

<p><b>^§</b>Number (%) of sample who had at least one parent complete more than at least high school education (i.e., at least some college/university).</p><p>*Number (%) with WHO BMI z-score classification overweight or obese</p><p>^ƗSites where boys had significantly higher values than girls (p<0.05).</p><p>^¥ST score = [(hours of TV on weekdays x 5) + (hours of TV on weekend days x 2) + (hours of video games and computers on weekdays x 5) + (hours of video games and computers on weekend days x 2)]/7</p><p>^ǂNumber (%) of children not meeting guidelines for ≤2 hours of screen time/day, in all sites, girls were significantly more likely to meet guidelines than boys (p<0.05).</p><p>BMI: Body Mass Index; SED: sedentary time; SD: standard deviation; ST: screen time; UK: United Kingdom; US: United States; OW/OB: overweight/obese.</p><p>Descriptive characteristics of all participants (<i>n</i> = 5,844).</p

Univariate correlates of total screen time (ST) (<i>n</i> = 5,844)^a.

<p>^aMulti-level general linear model controlling for sex, age, and highest parental education, with school and ISCOLE site as a random effects; unstandardized beta coefficients and standard errors are presented.</p><p>^bISCOLE used a variety of measures to assess adiposity, all of which were significant in univariate analyses. Akaike information criterion, Bayesian information criterion, and level of significance were used to determine which measure of adiposity provided the closest fit for the data. Waist circumference alone provided the best fit.</p><p>^cWHO BMI z-score classification. PA: physical activity; SE: Standard error; TV: television</p><p>Univariate correlates of total screen time (ST) (<i>n</i> = 5,844)<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129622#t004fn001" target="_blank">^a</a>.</p