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BackgroundIndependent of physical activity levels, youth sedentary behaviors (SB) have negative health outcomes. SB prevalence estimates during discretionary periods of the day (e.g., after-school), inform the need for targeted period-specific interventions. This systematic review aimed to determine children’s and adolescents’ SB prevalence during the after-school period.MethodsA computerized search was conducted in October 2015 (analysed November 2015). Inclusion criteria were: published in a peer-reviewed English journal; participants aged 5-18 years; measured overall after-school sedentary time (ST) objectively, and/or specific after-school SBs (e.g., TV viewing) objectively or subjectively; and provided the percentage of the after-school period spent in ST/SB or duration of behavior and period to calculate this. Where possible, findings were analyzed by location (e.g., after-school care/‘other’ locations). The PRISMA guidelines were followed.ResultsTwenty-nine studies were included: 24 included children (≤12 years), four assessed adolescents (>12 years) and one included both; 20 assessed ST and nine assessed SB. On average, children spent 41 % and 51 % of the after-school period in ST when at after-school care and other locations respectively. Adolescents spent 57 % of the after-school period in ST. SBs that children and adolescents perform include: TV viewing (20 % of the period), non-screen based SB (including homework; 20 %), screen-based SB (including TV viewing; 18 %), homework/academics (13 %), motorised transport (12 %), social SB (9 %), and screen-based SB (excluding TV viewing; 6 %).ConclusionChildren spent up to half of the after-school period in ST and this is higher among adolescents. A variety of screen- and non-screen based SBs are performed after school, providing key targets for interventions.Trial registrationPROSPERO registration number CRD42015010437Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-016-0419-1) contains supplementary material, which is available to authorized users.

BackgroundChildren and adolescents spend a large proportion of the after-school period in sedentary behaviors (SB). Identifying context-specific correlates is important for informing strategies to reduce these behaviors. This paper systematically reviews the correlates of children’s and adolescents’ after-school SB.MethodsA computerized literature search was performed in October 2015 for peer-reviewed original research journal articles published in English before October 2015. Eligibility criteria included: 1) sample aged 5–18 years; 2) quantified the amount of SB or component of this that the children/adolescents were performing after school; 3) a measure of SB as the dependent outcome; and 4) the association between potential correlates and after-school SB.ResultsData were synthesized in October 2015. Thirty-one studies met the eligibility criteria: 22 studies among children (≤12 years), six among adolescents (>12 years), two had a combined sample of children and adolescents and one cohort followed children from childhood to adolescence. Findings were separated by after-school location i.e. after-school programs (n = 4 studies) and unidentified locations (n = 27). There was insufficient evidence to draw conclusions on all but two of the 58 potential correlates: sex and age. Among children at unidentified locations there was a null association between sex (male) and overall after-school SB, a null association between sex (male) and after-school TV viewing, a positive association between age and overall after-school SB and an inconsistent association between age and after-school TV viewing. No correlates of after-school sedentary behaviour while at after-school programs were identified.ConclusionsOnly two correlates have been investigated frequently enough to determine an overall association; neither correlate is modifiable. Due to the lack of consistent investigation of potential correlates, further evidence is required to accurately identify potential intervention targets.PROSPERO registration numberCRD42014009180Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-2659-4) contains supplementary material, which is available to authorized users.

ObjectiveThe purpose of the current study was to examine associations of individual and aggregated screen-based behaviours, and total sitting time, with healthy and unhealthy dietary intakes among adolescents.DesignCross-sectional study of adolescents. Participants self-reported durations of television viewing, computer use, playing electronic games (e-games), total sitting time, daily servings of fruits and vegetables, and frequency of consumption of sugar-sweetened beverages (SSB), diet beverages, fast foods and discretionary snacks. Logistic regression models were conducted to identify associations of screen-based behaviours, total screen time and total sitting time with dietary intakes.SettingVictoria, Australia.SubjectsAdolescents (n 939) in School Year 11 (mean age 16·8 years).ResultsThe results showed that watching television (≥2 h/d) was positively associated with consuming SSB and diet beverages each week and consuming discretionary snacks at least once daily, whereas computer use (≥2 h/d) was inversely associated with daily fruit and vegetable intake and positively associated with weekly fast-food consumption. Playing e-games (any) was inversely associated with daily vegetable intake and positively associated with weekly SSB consumption. Total screen (≥2 h/d) and sitting (h/d) times were inversely associated with daily fruit and vegetable consumption, with total screen time also positively associated with daily discretionary snack consumption and weekly consumption of SSB and fast foods.ConclusionsIndividual and aggregated screen-based behaviours, as well as total sitting time, are associated with a number of indicators of healthy and unhealthy dietary intake. Future research should explore whether reducing recreational screen time improves adolescents’ diets.

BackgroundModifying the built environment by improving parks is potentially a sustainable way to increase population level physical activity. Despite considerable investment in parks and park renovations, few natural experiments on the impact of improving amenities on park use and park-based physical activity have been conducted. REVAMP is a natural experiment that aims to examine whether park improvement increases overall park usage, park-based physical activity and active travel to and from the park in the intervention compared with the control park over a two-year period; and to identify which specific aspects of the park refurbishment attracts park visitors and encourages park users to be more active. This paper describes the methods of the REVAMP study.MethodsThe intervention park is a large regional park (329 hectares) located in a low socio-economic status (SES) area in the north-eastern suburbs of Melbourne, Australia. The control park is a regional park (120 hectares) located in a high SES area in the eastern suburbs of Melbourne. Multiple methodologies to evaluate the impact of the park renovation are being employed including: cross-sectional surveys of local residents living near the two parks, direct observations of park users, intercept surveys with park users, and electronic monitoring of path usage and car traffic within the parks. Baseline measures were conducted in April-May 2013 (T1), and an innovative play space suitable for children of all ages and abilities was installed at the intervention park between September 2013 and February 2014. Follow-up measures will be repeated in April-May 2014 (T2) and April-May 2015 (T3). All methodologies will be completed at both the intervention and control parks at all three time-points, with the exception of the cross-sectional survey of local residents which will only be conducted at T1 and T3.ConclusionThis research will inform future park developments, and will contribute to creating an evidence base of the impact of park refurbishment, and the development of natural experiment methodology.Trial RegistrationCurrent controlled trial ISRCTN50745547, registration date 11.1.2014.