A cluster-randomized controlled trial to reduce sedentary behavior and promote physical activity and health of 8-9 year olds: the Transform-Us! study

Interventions to prevent obesity in children aged 5 to 11 years old

BACKGROUND

Prevention of obesity in children is an international public health priority given the prevalence of the condition (and its significant impact on health, development and well-being). Interventions that aim to prevent obesity involve behavioural change strategies that promote healthy eating or 'activity' levels (physical activity, sedentary behaviour and/or sleep) or both, and work by reducing energy intake and/or increasing energy expenditure, respectively. There is uncertainty over which approaches are more effective and numerous new studies have been published over the last five years, since the previous version of this Cochrane review.

OBJECTIVES

To assess the effects of interventions that aim to prevent obesity in children by modifying dietary intake or 'activity' levels, or a combination of both, on changes in BMI, zBMI score and serious adverse events.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was February 2023.

SELECTION CRITERIA

Randomised controlled trials in children (mean age 5 years and above but less than 12 years), comparing diet or 'activity' interventions (or both) to prevent obesity with no intervention, usual care, or with another eligible intervention, in any setting. Studies had to measure outcomes at a minimum of 12 weeks post baseline. We excluded interventions designed primarily to improve sporting performance.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our outcomes were body mass index (BMI), zBMI score and serious adverse events, assessed at short- (12 weeks to < 9 months from baseline), medium- (9 months to < 15 months) and long-term (≥ 15 months) follow-up. We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

This review includes 172 studies (189,707 participants); 149 studies (160,267 participants) were included in meta-analyses. One hundred forty-six studies were based in high-income countries. The main setting for intervention delivery was schools (111 studies), followed by the community (15 studies), the home (eight studies) and a clinical setting (seven studies); one intervention was conducted by telehealth and 31 studies were conducted in more than one setting. Eighty-six interventions were implemented for less than nine months; the shortest was conducted over one visit and the longest over four years. Non-industry funding was declared by 132 studies; 24 studies were funded in part or wholly by industry. Dietary interventions versus control Dietary interventions, compared with control, may have little to no effect on BMI at short-term follow-up (mean difference (MD) 0, 95% confidence interval (CI) -0.10 to 0.10; 5 studies, 2107 participants; low-certainty evidence) and at medium-term follow-up (MD -0.01, 95% CI -0.15 to 0.12; 9 studies, 6815 participants; low-certainty evidence) or zBMI at long-term follow-up (MD -0.05, 95% CI -0.10 to 0.01; 7 studies, 5285 participants; low-certainty evidence). Dietary interventions, compared with control, probably have little to no effect on BMI at long-term follow-up (MD -0.17, 95% CI -0.48 to 0.13; 2 studies, 945 participants; moderate-certainty evidence) and zBMI at short- or medium-term follow-up (MD -0.06, 95% CI -0.13 to 0.01; 8 studies, 3695 participants; MD -0.04, 95% CI -0.10 to 0.02; 9 studies, 7048 participants; moderate-certainty evidence). Five studies (1913 participants; very low-certainty evidence) reported data on serious adverse events: one reported serious adverse events (e.g. allergy, behavioural problems and abdominal discomfort) that may have occurred as a result of the intervention; four reported no effect. Activity interventions versus control Activity interventions, compared with control, may have little to no effect on BMI and zBMI at short-term or long-term follow-up (BMI short-term: MD -0.02, 95% CI -0.17 to 0.13; 14 studies, 4069 participants; zBMI short-term: MD -0.02, 95% CI -0.07 to 0.02; 6 studies, 3580 participants; low-certainty evidence; BMI long-term: MD -0.07, 95% CI -0.24 to 0.10; 8 studies, 8302 participants; zBMI long-term: MD -0.02, 95% CI -0.09 to 0.04; 6 studies, 6940 participants; low-certainty evidence). Activity interventions likely result in a slight reduction of BMI and zBMI at medium-term follow-up (BMI: MD -0.11, 95% CI -0.18 to -0.05; 16 studies, 21,286 participants; zBMI: MD -0.05, 95% CI -0.09 to -0.02; 13 studies, 20,600 participants; moderate-certainty evidence). Eleven studies (21,278 participants; low-certainty evidence) reported data on serious adverse events; one study reported two minor ankle sprains and one study reported the incident rate of adverse events (e.g. musculoskeletal injuries) that may have occurred as a result of the intervention; nine studies reported no effect. Dietary and activity interventions versus control Dietary and activity interventions, compared with control, may result in a slight reduction in BMI and zBMI at short-term follow-up (BMI: MD -0.11, 95% CI -0.21 to -0.01; 27 studies, 16,066 participants; zBMI: MD -0.03, 95% CI -0.06 to 0.00; 26 studies, 12,784 participants; low-certainty evidence) and likely result in a reduction of BMI and zBMI at medium-term follow-up (BMI: MD -0.11, 95% CI -0.21 to 0.00; 21 studies, 17,547 participants; zBMI: MD -0.05, 95% CI -0.07 to -0.02; 24 studies, 20,998 participants; moderate-certainty evidence). Dietary and activity interventions compared with control may result in little to no difference in BMI and zBMI at long-term follow-up (BMI: MD 0.03, 95% CI -0.11 to 0.16; 16 studies, 22,098 participants; zBMI: MD -0.02, 95% CI -0.06 to 0.01; 22 studies, 23,594 participants; low-certainty evidence). Nineteen studies (27,882 participants; low-certainty evidence) reported data on serious adverse events: four studies reported occurrence of serious adverse events (e.g. injuries, low levels of extreme dieting behaviour); 15 studies reported no effect. Heterogeneity was apparent in the results for all outcomes at the three follow-up times, which could not be explained by the main setting of the interventions (school, home, school and home, other), country income status (high-income versus non-high-income), participants' socioeconomic status (low versus mixed) and duration of the intervention. Most studies excluded children with a mental or physical disability.

AUTHORS' CONCLUSIONS

The body of evidence in this review demonstrates that a range of school-based 'activity' interventions, alone or in combination with dietary interventions, may have a modest beneficial effect on obesity in childhood at short- and medium-term, but not at long-term follow-up. Dietary interventions alone may result in little to no difference. Limited evidence of low quality was identified on the effect of dietary and/or activity interventions on severe adverse events and health inequalities; exploratory analyses of these data suggest no meaningful impact. We identified a dearth of evidence for home and community-based settings (e.g. delivered through local youth groups), for children living with disabilities and indicators of health inequities.

The association between device-measured sitting time and cardiometabolic health risk factors in children

BACKGROUND

There is limited evidence of the associations between postural-derived sitting time, waist-worn derived sedentary time and children's health and the moderation effect of physical activity (PA). This study examined associations of children's device-measured sitting time with cardiometabolic health risk factors, including moderation by physical activity.

METHODS

Cross-sectional baseline data from children (mean-age 8.2 ± 0.5 years) in Melbourne, Australia (2010) participating in the TransformUs program were used. Children simultaneously wore an activPAL to assess sitting time and an ActiGraph GT3X to assess sedentary time and physical activity intensity. Cardiometabolic health risk factors included: adiposity (body mass index [BMI], waist circumference [WC]), systolic and diastolic blood pressure (SBP, DBP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), cholesterol, triglycerides, fasting plasma glucose (FPG), serum insulin, and 25-hydroxyvitaminD (25[OH]D). Linear regression models (n = 71-113) assessed associations between sitting time with each health risk factor, adjusted for different PA intensities (i.e. light [LIPA], moderate-vigorous intensities [MVPA], separately on each model), age, sex, adiposity, and clustering by school. Interaction terms examined moderation. The analyses were repeated using device-measured sedentary time (i.e. ActiGraph GT3X) for comparison.

RESULTS

Sitting time was positively associated with SBP (b = 0.015; 95%CI: 0.004, 0.026), DBP (b = 0.012; 95%CI:0.004, 0.020), and FPG (b = 0.001; 95%CI: 0.000, 0.000), after adjusting for higher PA intensities. The association between sitting time and insulin (b = 0.003; 95%CI: 0.000, 0.006) was attenuated after adjusting for higher PA intensities. When the models were adjusted for LIPA and MVPA, there was a negative association with LDL (b=-0.001; 95%CI: -0.002, -0.000 and b=-0.001; 95%CI: -0.003, -0.000, respectively). There was a negative association of sedentary time with WCz (b=-0.003; 95%CI: -0.005, 0.000) and BMIz (b=-0.003; 95%CI: -0.006, -0.000) when the models were adjusted by MVPA. Sedentary time was positively associated with triglycerides (b = 0.001; 95%CI: 0.000, 0.001) but attenuated after adjusting for MVPA. No evidence of moderation effects was found.

CONCLUSIONS

Higher volumes of sitting and sedentary time were associated with some adverse associations on some cardiometabolic health risk factors in children. These associations were more evident when sitting time was the predictor. This suggests that reducing time spent sitting may benefit some cardiometabolic health outcomes, but future experimental research is needed to confirm causal relationships and identify the biological mechanisms that might be involved.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12609000715279.

Cost-effectiveness of reducing children's sedentary time and increasing physical activity at school: the Transform-Us! intervention

BACKGROUND

Improving physical activity and reducing sedentary behavior represent important areas for intervention in childhood in order to reduce the burden of chronic disease related to obesity and physical inactivity in later life. This paper aims to determine the cost-effectiveness of a multi-arm primary school-based intervention to increase physical activity and/or reduce sedentary time in 8-9 year old children (Transform-Us!).

METHODS

Modelled cost-utility analysis, using costs and effects from a cluster randomized controlled trial of a 30-month intervention that used pedagogical and environmental strategies to reduce and break up sedentary behaviour (SB-I), promote physical activity (PA-I), or a combined approach (PA + SB-I), compared to current practice. A validated multiple-cohort lifetable model (ACE-Obesity Policy model) estimated the obesity and physical activity-related health outcomes (measured as change in body mass index and change in metabolic equivalent task minutes respectively) and healthcare cost-savings over the cohort's lifetime from the public-payer perspective, assuming the intervention was delivered to all 8-9 year old children attending Australian Government primary schools. Sensitivity analyses tested the impact on cost-effectiveness of varying key input parameters, including maintenance of intervention effect assumptions.

RESULTS

Cost-effectiveness results demonstrated that, when compared to control schools, the PA-I and SB-I intervention arms were "dominant", meaning that they resulted in net health benefits and healthcare cost-savings if the intervention effects were maintained. When the costs and effects of these intervention arms were extrapolated to the Australian population, results suggested significant potential as obesity prevention measures (PA-I: 60,780 HALYs saved (95% UI 15,007-109,413), healthcare cost-savings AUD641M (95% UI AUD165M-$1.1B); SB-I: 61,126 HALYs saved (95% UI 11,770 - 111,249), healthcare cost-savings AUD654M (95% UI AUD126M-1.2B)). The PA-I and SB-I interventions remained cost-effective in sensitivity analysis, assuming the full decay of intervention effect after 10 years.

CONCLUSIONS

The PA-I and SB-I Transform-Us! intervention arms represent good value for money and could lead to health benefits and healthcare cost-savings arising from the prevention of chronic disease in later life if intervention effects are sustained.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number (ISRCTN83725066). Australia and New Zealand Clinical Trials Registry Number (ACTRN12609000715279).

Primary school learners' movement during class time: perceptions of educators in the Western Cape, South Africa

BACKGROUND

Over the last decade, the efficacy of in-classroom movement to reduce sedentary behaviour has been mainly conducted in high-income, developed countries. To date, there have been no published reports on the perceptions of principals and teachers regarding learners' movement during class time to inform the implementation of classroom-based movement strategies to reduce sedentariness in South Africa.

METHODS

A sample of primary school principals and grades 5 and 6 teachers from a range of socio-economic categories participated in this exploratory, descriptive qualitative study in the metro central district of the Western Cape Education Department in South Africa. Transcripts of individual depth interviews (IDIs) with principals and focus group discussions (FGDs) with teachers were coded using Atlast ti 9* software for qualitative analysis.

RESULTS

Thirteen principals (13 IDIs) and 24 teachers (6 FGDs) participated in the study. Two main factors influencing in-classroom movement, namely teacher-related and structural factors, were identified. The teacher-related factors pertained to their classroom management practice, knowledge and beliefs about sitting, and management style influenced their role in delivering the curriculum and creating a classroom environment conducive for learning. Classroom factors pertained to classroom size, the number of learners in the class and the ergonomic utility of traditional classroom desks. Institutional expectations and acceptance of learners' behaviour, and teachers' practice were also notable contributing factors that influenced learners' movement during class time.

CONCLUSION

Emerging evidence about the efficacy of in-classroom movement on sedentary behaviour and learning outcomes challenges traditional teacher practice that sitting is essential for the delivery of the curriculum and for creating an optimal learning environment. Teacher training about the behaviour control utility of in-classroom movement, and school management and policy supportive of in-classroom movement may encourage fidelity to in-classroom movement strategies.

Scaling up a school-based intervention to increase physical activity and reduce sedentary behaviour in children: protocol for the TransformUs hybrid effectiveness-implementation trial

INTRODUCTION

Efficacious programmes require implementation at scale to maximise their public health impact. TransformUs is an efficacious behavioural and environmental intervention for increasing primary (elementary) school children's (5-12 years) physical activity and reducing their sedentary behaviour within school and home settings. This paper describes the study protocol of a 5-year effectiveness-implementation trial to assess the scalability and effectiveness of the TransformUs programme.

METHODS AND ANALYSIS

A type II hybrid implementation-effectiveness trial, TransformUs is being disseminated to all primary schools in the state of Victoria, Australia (n=1786). Data are being collected using mixed methods at the system (state government, partner organisations), organisation (school) and individual (teacher, parent and child) levels. Evaluation is based on programme Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework. RE-AIM domains are being measured using a quasi-experimental, pre/post, non-equivalent group design, at baseline, 12 and 24 months. Effectiveness will be determined in a subsample of 20 intervention schools (in Victoria) and 20 control schools (in New South Wales (NSW), Australia), at baseline, 12 and 24 months. Primary outcomes include TransformUs Reach, Adoption, Implementation and organisational Maintenance (implementation trial), and children's physical activity and sedentary time assessed using accelerometers (effectiveness trial). Secondary outcomes include average sedentary time and moderate to vigorous-intensity physical activity on weekdays and during school hours, body mass index z-scores and waist circumference (effectiveness trial). Linear mixed-effects models will be fitted to compare outcomes between intervention and control participants accounting for clustering of children within schools, confounding and random effects.

ETHICS AND DISSEMINATION

The trial was approved by the Deakin University Human Research Ethics Committee (HEAG-H 28_2017), Victorian Department of Education, the NSW Department of Education, Australian Catholic University (2017-145R), Melbourne Archdiocese Catholic Schools and Catholic Schools NSW. Partners, schools/teachers and parents will provide an informed signed consent form prior to participating. Parents will provide consent for their child to participate in the effectiveness trial. Findings will be disseminated via peer-reviewed publications, scientific conferences, summary reports to schools and our partner organisations, and will inform education policy and practice on effective and sustainable ways to promote physical activity and reduce sedentary behaviours population-wide.

TRIAL REGISTRATION NUMBER

Australian Clinical Trials Registration Registry (ACTRN12617000204347).

Exploring Children's Self-Reported Activity Compensation: The REACT Study

PURPOSE

Previous research has focused on device-based measures of activity compensation, with little understanding of how children perceive potential compensatory responses to activity or inactivity, or whether these change after periods of activity or inactivity. The aim of this study was (a) to explore the alignment between children's self-reported usual compensation and compensation recall after experimental conditions and (b) to examine sex differences.

METHODS

In total, 360 children (47% boys) participated in at least one of three experimental conditions over 6 wk: (a) restricted physical activity (PA; indoor play), (b) imposed moderate- to vigorous-intensity PA (MVPA; sports class), and (c) imposed light-intensity PA (LPA; standing lesson). Before the first condition, children reported their "usual compensation" behavior to examples of restricted/imposed PA, and 2-3 d after each experimental condition, they completed a recall measure of their compensation after the condition. Multilevel regression models were conducted to determine whether children's perceptions of "usual compensation" score were associated with recalled compensation score after imposed or restricted PA. Additional models were fitted for sex-specific associations.

RESULTS

Overall and among girls, the usual compensation score was positively associated with the compensatory recall score for the additional MVPA and LPA conditions ( P < 0.0005; e.g., they thought they would usually compensate for additional MVPA and then perceived that they compensated after additional MVPA). A negative association was seen in the restricted activity condition among girls ( P = 0.03). All associations in the boys' analyses were statistically nonsignificant.

CONCLUSIONS

These findings suggest some alignment between children's self-reported usual compensation and compensation recall after imposed changes to routine activity. Future research should consider device-measured comparisons and identify characteristics of children at risk of activity compensation in future interventions.

Effectiveness of multilevel interventions based on socio-ecological model to decrease sedentary time in children: a systematic review of controlled studies

Objectives

Preventive actions of sedentary behavior (SB) based on the socio-ecological model are needed among children and young adolescents. The aim of this systematic review is to ascertain the effectiveness of multilevel interventions (i.e., involving consideration of at least two interventional levels) in reducing sedentary time (ST) in children aged 5-12 years.

Methods

Adhering to PRISMA guidelines, a systematic literature search was conducted in three databases (PsyInfo, PubMed and ERIC) until July 2021.

Results

30 trials met the eligibility criteria and were included. They showed acceptable (< 8, n = 18) and high (≥ 8, n = 12) methodological quality. Among studies targeting 2 (n = 2), 3 (n = 19) and 4 levels (n = 9), 1 (50%), 9 (47%) and 7 (78%) were effective and reported significant reduction of ST, respectively.

Conclusion

Interventions tend to be more effective when they involve 4 levels, using both agentic and structural strategies (targeting intrinsic determinants, in the organizational environment of the child). Findings underline the relevance of multilevel strategies to reduce ST in children, but also raise issues about operationalization of the socio-ecological perspective.

Systematic review registration

PROSPERO, identifier: CRD42020209653.

Transform-Us! cluster RCT: 18-month and 30-month effects on children's physical activity, sedentary time and cardiometabolic risk markers

OBJECTIVE

To test the efficacy of the Transform-Us! school- and home-based intervention on children's physical activity (PA), sedentary behaviour (SB) and cardiometabolic risk factor profiles.

METHODS

A 30-month 2×2 factorial design cluster randomised controlled trial delivered in 20 primary schools (148 Year 3 classes) in Melbourne, Australia (2010-2012), that used pedagogical and environmental strategies to reduce and break up SB, promote PA or a combined approach, compared with usual practice. Primary outcomes (accelerometry data; n=348) were assessed at baseline, 18 and 30 months. Secondary outcomes included body mass index (BMI) and waist circumference (WC) (n=564), blood pressure (BP) (n=537) and biomarkers (minimum n=206). Generalised linear mixed models estimated the interactive effects of the PA and SB interventions on the outcomes. If there was no interaction, the main effects were assessed.

RESULTS

At 18 months, there were intervention effects on children's weekday SB (-27 min, 95% CI: -47.3 to -5.3) for the PA intervention, and on children's average day PA (5.5 min, 95% CI: 0.1 to 10.8) for the SB intervention. At 30 months, there was an intervention effect for children's average day SB (-33.3 min, 95% CI: -50.6 and -16.0) for the SB intervention. Children's BMI (PA and SB groups) and systolic BP (combined group) were lower, and diastolic BP (PA group) was higher. There were positive effects on WC at both time points (SB intervention) and mixed effects on blood parameters.

CONCLUSIONS

The Transform-Us! PA and SB interventions show promise as a pragmatic approach for reducing children's SB and adiposity indicators; but achieving substantial increases in PA remains challenging.

TRIAL REGISTRATION

ISRCTN83725066; ACTRN12609000715279.

Feasibility and Acceptability of a Classroom-Based Active Breaks Intervention for 8-12-Year-Old Children

Purpose: This study explored the feasibility of conducting a classroom-based active breaks intervention on sedentary behavior (SB), physical activity (PA) and attention in 8-12-year-old children. Methods: Eight schools were randomized on a 1:1 basis to the control or intervention. Teachers selected 10 cards detailing an activity break at random. Children then undertook each of the ten activity breaks for 30 s, three times per day for 6 weeks. School and participant recruitment, attrition rates, percentage of outcome measures collected, and acceptability were used to explore the feasibility of the study. Mixed effects models were undertaken to examine intervention effects upon measures of PA, SB and attention. Results: Two hundred and thirty-nine consent forms were issued and 153 were returned (64%). Of the 153 consents, 146 children (95%) were measured at baseline, and 117 participated in the follow-up measures (80%) 6 weeks later suggesting the intervention was acceptable for the participants. From teacher interviews, it was noted that the intervention was feasible to implement, and teachers observed positive classroom behavior changes in children. Inclusion rates for outcome measures ranged from 49% to 66%. Significant, intervention effects were observed for sitting time (B = -27.19; 95%CI: -36.84, -17.17), standing time (B = 23.51; 95%CI 14.1, 32.45) and the number of sit to stand transitions (B = 16.1; 95%CI 4.7, 26.79). Conclusion: Findings suggest that it was feasible and acceptable to implement an active breaks intervention within the classroom setting. Future work should consider the effectiveness of implementing this intervention across a full academic year.

The association of socioeconomic status with sedentary behaviour and moderate-to-vigorous intensity physical activity among children with intellectual disability

Background: While socioeconomic status (SES) has been shown to be an important determinant of sedentary behaviour (SB) and moderate-to-vigorous intensity physical activity (MVPA) in typically developing children, similar data on those with intellectual disability (ID) are lacking. This study explored the association of SES with SB and MVPA among Chinese children with ID. Method: Data were collected from 275 children aged 7-16 with mild to severe ID. Children's Leisure Activities Study Survey assessed SB and MVPA for a week. SES was assessed using the six indicators. Multiple linear regression was used to analyse the associations of SES variables with SB and MVPA on schooldays and on weekends. Results: Parental education level was positively associated with SB on weekends, and MVPA on schooldays and weekends; family's combined annual income was positively associated MVPA on schooldays and weekends; parental occupation was positively associated with SB on schooldays and weekends; Family Affluence Scale was positively associated with SB on schooldays (all p < 0.05). Conclusion: SES plays a significant role in influencing SB and MVPA in children with ID. Results suggest that interventions should focus on increasing MVPA for children with lower SES, while families with higher SES should limit their children's SB.

Is level of implementation linked with intervention outcomes? Process evaluation of the TransformUs intervention to increase children’s physical activity and reduce sedentary behaviour

Background

TransformUs was a four-arm school-based intervention to increase physical activity and reduce sedentary behaviour among primary school children. Pedagogical and environmental strategies targeted the classroom, school grounds and family setting. The aims of this study were to evaluate program fidelity, dose, appropriateness, satisfaction and sustainability, and associations between implementation level and outcomes among the three intervention arms.

Methods

At baseline, 18-months (mid-intervention) and 30-months (post-intervention), teachers, parents and children completed surveys, and children wore GT3X ActiGraph accelerometers for 8 days at each time point to determine physical activity and sedentary time. Implementation data were pooled across the three intervention groups and teachers were categorised by level of implementation: (i) ‘Low’ (< 33% delivered); (ii) ‘Moderate’ (33–67% delivered); and (iii) ‘High’ (> 67% delivered). Linear and logistic mixed models examined between group differences in implementation, and the association with children’s physical activity and sedentary time outcomes. Qualitative survey data were analysed thematically.

Results

Among intervention recipients, 52% (n = 85) of teachers, 29% (n = 331) of parents and 92% (n = 407) of children completed baseline evaluation surveys. At 18-months, teachers delivered on average 70% of the key messages, 65% set active/standing homework, 30% reported delivering > 1 standing lesson/day, and 56% delivered active breaks per day. The majority of teachers (96%) made activity/sports equipment available during recess and lunch, and also used this equipment in class (81%). Fidelity and dose of key messages and active homework reduced over time, whilst fidelity of standing lessons, active breaks and equipment use increased. TransformUs was deemed appropriate for the school setting and positively received. Implementation level and child behavioural outcomes were not associated. Integration of TransformUs into existing practices, children’s enjoyment, and teachers’ awareness of program benefits all facilitated delivery and sustainability.

Conclusions

This study demonstrated that intervention dose and fidelity increased over time, and that children’s enjoyment, senior school leadership and effective integration of interventions into school practices facilitated improved intervention delivery and sustainability. Teacher implementation level and child behavioural outcomes were unrelated, suggesting intervention efficacy was achieved irrespective of implementation variability. The potential translatability of TransformUs into practice contexts may therefore be increased. Findings have informed scale-up of TransformUs across Victoria, Australia.

Trial registration

International Standard Randomized Controlled Trial Number ISRCTN83725066; Australian New Zealand Clinical Trials Registry Number ACTRN12609000715279. Registered 19 August 2009. Available at: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=308387&isReview=true

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01354-5.

Health and Academic Performance With Happy Children: A Controlled Longitudinal Study Based on the HOPP Project

Background

Overweight/obesity in children and adolescents, largely arising due to increased food intake and reduced physical activity, is a major health concern. Physical activity (PA) integrated into learning has been shown to not only lead to improved health outcomes and wellbeing but also positively affect academic performance. The Health and Academic Performance with Happy Children (HAPHC) project aims at enhancing health and academic performance in elementary school children via implementation of a daily unit of Physical Activity Across the Curriculum (PAAC), which is carried out within the school setting. In this project, PA as an integrated part of learning will be evaluated and the learning material adapted for a large scale implementation across several European countries.

Methods

In three European countries (Austria, Slovenia, and Belgium), 12 primary schools in total will be recruited to act as either intervention or control school in a large intervention study, which applies the PAAC pedagogy during lectures. It is estimated that, at least 3,000+ children across the three countries will be recruited in this study. All teachers of intervention schools will receive training and materials/teaching equipment that will allow them to integrate a daily PA unit of 45 min over 3 years across the curriculum. In response to the daily PA intervention, the following primary outcomes will be assessed: changes in health related physiological factors, academic achievement, psycho-social aspects and wellbeing.

Impact of Project

The HAPHC project aims at promoting public health by increasing PA at an early age within the school setting and therewith preventing the increasing risk of non-communicable diseases across Europe. HAPHC project aims to develop knowledge and materials, which will ensure that the PAAC can be scalable to other European countries.

Trial Registration Number

ClinicalTrials.gov, identifier: NCT04956003.

Interventions to Promote Physical Activity and Healthy Digital Media Use in Children and Adolescents: A Systematic Review

OBJECTIVES

To identify effective interventions that promote healthy screen time use and reduce sedentary behavior in school-age children and adolescents (SACA) in all settings, over the last 20 years.

METHODS

Searches were conducted from 2000 until March 2021 using PubMed, Embase, Medline, PsycINFO, Ovid SP, The Cochrane Library, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, and the WHO regional databases, including Google Scholar and reference lists of relevant articles and reviews. Randomized-controlled trials and quasi-experimental studies assessing interventions to reduce sedentary behaviors and screen time in healthy SACA (aged 5-19.9 years) globally. Data were extracted by 2 reviewers and where possible, pooled with a random-effects model.

RESULTS

The review included 51 studies, of which 23 were included in meta-analyses with 16 418 children and adolescents. Nondigital randomized-controlled trials reported a small, but significant reduction of TV-specific screen time (minutes per day) (mean difference, -12.46; 95% confidence interval, -20.82 to -4.10; moderate quality of evidence) and sedentary behavior (minutes per day) (mean difference, -3.86; 95% confidence interval, -6.30 to -1.41; participants = 8920; studies = 8; P = .002; moderate quality of evidence) as compared with control groups. For quasi-experimental studies, nondigital interventions may make little or no difference on screen time (minutes per day) or sedentary behavior (minutes per day), given the high uncertainty of evidence. Most studies were conducted in a high-income country. Generalizability of results to low- and middle- income countries remain limited.

CONCLUSIONS

Public health policies and programs will be necessary to reduce excessive sedentary behavior and screen time, especially in the post-coronavirus disease 2019 reality.

“When You Move You Have Fun”: Perceived Barriers, and Facilitators of Physical Activity From a Child's Perspective

In Northern Ireland (NI), many children do not meet the recommended levels of physical activity (PA). To reduce the prevalence of physical inactivity and associated health conditions, it is important to understand the influences on children's PA, which in turn has the potential to inform future intervention design. The purpose of this formative study was to examine the current views, barriers, facilitators, experiences, and perceptions of children in relation to PA in the classroom, school, and home environments, and to assess the acceptability of components for a school-based intervention. Write and draw tasks and semi-structured focus groups (n = 10) were conducted with 50 children aged 7–9 years (22 boys, 28 girls) from six primary schools. Focus groups were recorded, transcribed, and analyzed thematically. Pen profiles were constructed from the transcripts in a deductive manner and represent key emergent themes. Results indicated that children's perception and knowledge of PA was mainly structured and sport-based, while some referred to fun, play and health. Fun, social support and outdoor activity were identified as key facilitators. Barriers included parental restrictions, lack of time and space in the different environments. The acceptability of intervention components was examined, children recognized the potential benefits of additional movement in the classroom, but opinions differed on the sit-to-stand desks. Findings contribute to a more detailed understanding of children's perceptions of context specific PA, the barriers they face, in addition to factors that support them to lead a physically active lifestyle, which may inform future PA promotion strategies.

Using compositional data analysis to explore accumulation of sedentary behavior, physical activity and youth health

PURPOSE

The study aimed to describe youth time-use compositions, focusing on time spent in shorter and longer bouts of sedentary behavior and physical activity (PA), and to examine associations of these time-use compositions with cardiometabolic biomarkers.

METHODS

Accelerometer and cardiometabolic biomarker data from 2 Australian studies involving youths 7-13 years old were pooled (complete cases with accelerometry and adiposity marker data, n = 782). A 9-component time-use composition was formed using compositional data analysis: time in shorter and longer bouts of sedentary behavior; time in shorter and longer bouts of light-, moderate-, or vigorous-intensity PA; and "other time" (i.e., non-wear/sleep). Shorter and longer bouts of sedentary time were defined as <5 min and ≥5 min, respectively. Shorter bouts of light-, moderate-, and vigorous-intensity PA were defined as <1 min; longer bouts were defined as ≥1 min. Regression models examined associations between overall time-use composition and cardiometabolic biomarkers. Then, associations were derived between ratios of longer activity patterns relative to shorter activity patterns, and of each intensity level relative to the other intensity levels and "other time", and cardiometabolic biomarkers.

RESULTS

Confounder-adjusted models showed that the overall time-use composition was associated with adiposity, blood pressure, lipids, and the summary score. Specifically, more time in longer bouts of light-intensity PA relative to shorter bouts of light-intensity PA was significantly associated with greater body mass index z-score (zBMI) (β = 1.79; SE = 0.68) and waist circumference (β = 18.35, SE = 4.78). When each activity intensity was considered relative to all higher intensities and "other time", more time in light- and vigorous-intensity PA, and less time in sedentary behavior and moderate-intensity PA, were associated with lower waist circumference.

CONCLUSION

Accumulating PA, particularly light-intensity PA, in frequent short bursts may be more beneficial for limiting adiposity compared to accumulating the same amount of PA at these intensities in longer bouts.

Teachers' Perspectives on the Acceptability and Feasibility of Wearable Technology to Inform School-Based Physical Activity Practices

Background: Many children are not engaging in sufficient physical activity and there are substantial between-children physical activity inequalities. In addition to their primary role as educators, teachers are often regarded as being well-placed to make vital contributions to inclusive visions of physical activity promotion. With the dramatic increase in popularity of wearable technologies for physical activity promotion in recent years, there is a need to better understand teachers' perspectives about using such devices, and the data they produce, to support physical activity promotion in schools. Method: Semi-structured interviews were conducted with 26 UK-based primary school teachers, exploring their responses to children's physical activity data and their views about using wearable technologies during the school day. Interview discussions were facilitated by an elicitation technique whereby participants were presented with graphs illustrating children's in-school physical activity obtained from secondary wearable technology data. Interview transcripts were thematically analyzed. Results: Most teachers spoke positively about the use of wearable technologies specifically designed for school use, highlighting potential benefits and considerations. Many teachers were able to understand and critically interpret data showing unequal physical activity patterns both within-and between-schools. Being presented with the data prompted teachers to provide explanations about observable patterns, emotional reactions-particularly about inequalities-and express motivations to change the current situations in schools. Conclusion: These findings suggest that primary school teachers in the UK are open to integrating wearable technology for measuring children's physical activity into their practices and can interpret the data produced by such devices. Visual representations of physical activity elicited strong responses and thus could be used when working with teachers as an effective trigger to inform school practices and policies seeking to address in-school physical inactivity and inequalities.

Seasonal variations in physical activity among Norwegian elementary school children in Arctic regions

The aim of this study was to measure seasonal variations in physical activity (PA) during Polar Nights (PN) and Polar Days (PD) among elementary school children in the Arctic regions of Norway. One hundred and seventy-eight schoolchildren from 1st, 3rd, 5thand 7th grade participated in the study. Physical activity was measured for seven consecutive days with an ActiGraph GT3X-BT accelerometer and is expressed as total PA incounts per minute (cpm) and moderate-to-vigorous activity (MVPA) (min∙day-1). During PN, 51% of boys and 33% of girls met the PA recommendations, whereas 36% of boys and 34% of girls met the recommendations during PD. Time spent doing MVPA did not differ between the two seasons (all p ≥ 0.073). Overall, the children accumulated 613 ±154 cpm during PN, which was lower than during PD 704 ± 269 cpm, p < 0.001). A larger proportion of boys than girls met the PA recommendations during PN compared with PD. Our findings did not show any clear seasonal variation for MVPA or total PA among children,except for some differences within sexes in different grades. This study indicates that interventions aimed at increasing PA should be implemented throughout the year in the Arctic regions. .

Changes in Families' Leisure, Educational/Work and Social Screen Time Behaviours before and during COVID-19 in Australia: Findings from the Our Life at Home Study

This study aimed to understand differences in leisure, educational/work and social screen time behaviours experienced by parents and children due to COVID-19 lockdown restrictions, which may inform behaviour change strategies and policy in the transition to a COVID-normal life. Participants in the "Our Life at Home" study (n = 218 parents from Australia, 43.4 ± 6.8 years, 88% female) completed a cross-sectional online survey in April/May 2020. Parents recalled their own and their child (8.7 ± 2.0 years, 42% female) or adolescents (15.0 ± 1.5 years, 50% female) participation in nine screen time behaviours in the past month (during lockdown) and retrospectively for February 2020 (pre-lockdown), providing data on 436 individuals. Screen time behaviours included leisure (computer/laptop and tablet/smartphone for leisure, TV/videos/DVDs and game consoles); education/work (computer/laptop and tablet/smartphone for work/education); and social screen time (computer/tablet/smartphone for social communication with friends, family and work (parents only)). Wilcoxon signed-rank tests and effect sizes (r) compared the time spent in each behaviour pre-lockdown and during lockdown. Large differences were observed in social (parents: r = 0.41-0.57; children: r = 0.55-0.65; adolescents: r = 0.28-0.43) and education (children: r = 0.50-0.65 and adolescents: r = 0.25-0.37) behaviours. There were small or no differences in leisure time screen use. COVID-19 lockdown restrictions have impacted parent's and children's screen time, and future research and policy should consider strategies to support families to manage screen time.

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6 to 18

BACKGROUND

Physical activity among children and adolescents is associated with lower adiposity, improved cardio-metabolic health, and improved fitness. Worldwide, fewer than 30% of children and adolescents meet global physical activity recommendations of at least 60 minutes of moderate to vigorous physical activity per day. Schools may be ideal sites for interventions given that children and adolescents in most parts of the world spend a substantial amount of time in transit to and from school or attending school.

OBJECTIVES

The purpose of this review update is to summarise the evidence on effectiveness of school-based interventions in increasing moderate to vigorous physical activity and improving fitness among children and adolescents 6 to 18 years of age. Specific objectives are: • to evaluate the effects of school-based interventions on increasing physical activity and improving fitness among children and adolescents; • to evaluate the effects of school-based interventions on improving body composition; and • to determine whether certain combinations or components (or both) of school-based interventions are more effective than others in promoting physical activity and fitness in this target population.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, BIOSIS, SPORTDiscus, and Sociological Abstracts to 1 June 2020, without language restrictions. We screened reference lists of included articles and relevant systematic reviews. We contacted primary authors of studies to ask for additional information.

SELECTION CRITERIA

Eligible interventions were relevant to public health practice (i.e. were not delivered by a clinician), were implemented in the school setting, and aimed to increase physical activity among all school-attending children and adolescents (aged 6 to 18) for at least 12 weeks. The review was limited to randomised controlled trials. For this update, we have added two new criteria: the primary aim of the study was to increase physical activity or fitness, and the study used an objective measure of physical activity or fitness. Primary outcomes included proportion of participants meeting physical activity guidelines and duration of moderate to vigorous physical activity and sedentary time (new to this update). Secondary outcomes included measured body mass index (BMI), physical fitness, health-related quality of life (new to this update), and adverse events (new to this update). Television viewing time, blood cholesterol, and blood pressure have been removed from this update.  DATA COLLECTION AND ANALYSIS: Two independent review authors used standardised forms to assess each study for relevance, to extract data, and to assess risk of bias. When discrepancies existed, discussion occurred until consensus was reached. Certainty of evidence was assessed according to GRADE. A random-effects meta-analysis based on the inverse variance method was conducted with participants stratified by age (children versus adolescents) when sufficient data were reported. Subgroup analyses explored effects by intervention type.

MAIN RESULTS

Based on the three new inclusion criteria, we excluded 16 of the 44 studies included in the previous version of this review. We screened an additional 9968 titles (search October 2011 to June 2020), of which 978 unique studies were potentially relevant and 61 met all criteria for this update. We included a total of 89 studies representing complete data for 66,752 study participants. Most studies included children only (n = 56), followed by adolescents only (n = 22), and both (n = 10); one study did not report student age. Multi-component interventions were most common (n = 40), followed by schooltime physical activity (n = 19), enhanced physical education (n = 15), and before and after school programmes (n = 14); one study explored both enhanced physical education and an after school programme. Lack of blinding of participants, personnel, and outcome assessors and loss to follow-up were the most common sources of bias.  Results show that school-based physical activity interventions probably result in little to no increase in time engaged in moderate to vigorous physical activity (mean difference (MD) 0.73 minutes/d, 95% confidence interval (CI) 0.16 to 1.30; 33 studies; moderate-certainty evidence) and may lead to little to no decrease in sedentary time (MD -3.78 minutes/d, 95% CI -7.80 to 0.24; 16 studies; low-certainty evidence). School-based physical activity interventions may improve physical fitness reported as maximal oxygen uptake (VO₂max) (MD 1.19 mL/kg/min, 95% CI 0.57 to 1.82; 13 studies; low-certainty evidence). School-based physical activity interventions may result in a very small decrease in BMI z-scores (MD -0.06, 95% CI -0.09 to -0.02; 21 studies; low-certainty evidence) and may not impact BMI expressed as kg/m² (MD -0.07, 95% CI -0.15 to 0.01; 50 studies; low-certainty evidence). We are very uncertain whether school-based physical activity interventions impact health-related quality of life or adverse events.

AUTHORS' CONCLUSIONS

Given the variability of results and the overall small effects, school staff and public health professionals must give the matter considerable thought before implementing school-based physical activity interventions. Given the heterogeneity of effects, the risk of bias, and findings that the magnitude of effect is generally small, results should be interpreted cautiously.

Identifying effective intervention strategies to reduce children's screen time: a systematic review and meta-analysis

BACKGROUND

Excessive screen time ([Formula: see text] 2 h per day) is associated with childhood overweight and obesity, physical inactivity, increased sedentary time, unfavorable dietary behaviors, and disrupted sleep. Previous reviews suggest intervening on screen time is associated with reductions in screen time and improvements in other obesogenic behaviors. However, it is unclear what study characteristics and behavior change techniques are potential mechanisms underlying the effectiveness of behavioral interventions. The purpose of this meta-analysis was to identify the behavior change techniques and study characteristics associated with effectiveness in behavioral interventions to reduce children's (0-18 years) screen time.

METHODS

A literature search of four databases (Ebscohost, Web of Science, EMBASE, and PubMed) was executed between January and February 2020 and updated during July 2021. Behavioral interventions targeting reductions in children's (0-18 years) screen time were included. Information on study characteristics (e.g., sample size, duration) and behavior change techniques (e.g., information, goal-setting) were extracted. Data on randomization, allocation concealment, and blinding was extracted and used to assess risk of bias. Meta-regressions were used to explore whether intervention effectiveness was associated with the presence of behavior change techniques and study characteristics.

RESULTS

The search identified 15,529 articles, of which 10,714 were screened for relevancy and 680 were retained for full-text screening. Of these, 204 studies provided quantitative data in the meta-analysis. The overall summary of random effects showed a small, beneficial impact of screen time interventions compared to controls (SDM = 0.116, 95CI 0.08 to 0.15). Inclusion of the Goals, Feedback, and Planning behavioral techniques were associated with a positive impact on intervention effectiveness (SDM = 0.145, 95CI 0.11 to 0.18). Interventions with smaller sample sizes (n < 95) delivered over short durations (< 52 weeks) were associated with larger effects compared to studies with larger sample sizes delivered over longer durations. In the presence of the Goals, Feedback, and Planning behavioral techniques, intervention effectiveness diminished as sample size increased.

CONCLUSIONS

Both intervention content and context are important to consider when designing interventions to reduce children's screen time. As interventions are scaled, determining the active ingredients to optimize interventions along the translational continuum will be crucial to maximize reductions in children's screen time.

Is replacing sedentary time with bouts of physical activity associated with inflammatory biomarkers in children?

This study aimed to investigate the theoretical impact of reallocating a specific amount of sedentary time with an equal amount of (a) total and (b) ≥1-minute bout-accumulated time spent in different activity intensities, on inflammatory biomarkers in 8- to 9-year-old children. Accelerometry and inflammatory biomarker baseline data from the Transform-Us! Study (complete cases n = 149) were utilized. Isotemporal linear models with the Gaussian distribution and identity link functions were used to assess associations between the activity replacements and seven individual inflammatory biomarkers, including C-reactive protein (CRP), and Interleukin (IL)-2, IL-6, IL-8, and IL-10, as well as combined inflammatory and pro-inflammatory composite scores. Eighty-five percent of children met physical activity recommendations. Replacing 10 minutes of sedentary time per day with VPA, regardless of how this was accumulated, was beneficially associated with CRP and both combined composite scores. In contrast, replacing 10 min/day of sedentary time with ≥ 1-minute MPA bouts was detrimentally associated with CRP and the inflammatory composite score. Substitutions with other activity intensities were not significantly associated with any individual inflammatory biomarkers, or combined inflammatory and pro-inflammatory composite scores. In healthy and active school-aged children, evidence of the theoretical impact of replacing sedentary time with physical activity, regardless of intensity or accumulation, on markers of systemic inflammation was limited. Longitudinal research is needed to investigate the long-term impacts of reallocating sedentary time with physical activity, and particularly VPA, for inflammatory biomarkers in children, including those with increased risk of inflammation.

Embedding Active Pedagogies within Pre-Service Teacher Education: Implementation Considerations and Recommendations

The physical activity levels of children in Australia are critically low and correlate with reduced academic achievement and poor health outcomes. Schools provide an ideal setting for physical activity interventions to help children move more. Instead of targeting in-service teachers, this study embedded an evidence-based active pedagogy program called Transform-Ed! into pre-service teacher education. Pre/post surveys and post-program interviews and focus group discussions were conducted with key stakeholders (n = 5), lecturers (n = 6), and pre-service teachers (n = 274) involved with the 12-week program. The design, implementation, and evaluation of the study were systematically guided by all five dimensions of Glasgow and colleagues’ RE-AIM (reach, effectiveness, adoption, implementation, and maintenance) framework. Linear mixed models, descriptive analysis and a framework approach were used to analyse the data. Significant improvements were observed in pre-service teachers’ willingness, confidence, and competence to implement physically active pedagogic strategies following the intervention. Pre-service teacher perceived effectiveness of such strategies on student outcomes also significantly increased and perceived barriers decreased. High adherence was consistently reported and the program was maintained after completion of the implementation trial by all lecturers. Four key themes spanning multiple dimensions and participant levels informed recommendations for program scalability: an “inter-systemic approach”, a “co-design” approach, “embedded in professional practice”, and “evidence of impact” on teacher practice. Anchored in real-world settings and tethered by implementation science, Transform-Ed! could have the potential to advance the teaching capability of teachers, and transform the learning experience and physical and academic outcomes of primary school students.

A qualitative study of school leader experiences adopting and implementing a whole of school physical activity and sedentary behaviour programme: Transform-Us!

Purpose

Little is known about the experiences of school leaders adopting and implementing real-world, scaled-up physical activity interventions in the Australian educational system. Transform-Us! is a novel physical activity and sedentary behaviour intervention available to all primary schools in Victoria, Australia, since September 2018. This study explored barriers and facilitators experienced by school leaders during the adoption and early implementation phases of Transform-Us!.

Design/methodology/approach

Qualitative study involving seven semi-structured telephone interviews with school leaders implementing Transform-Us! in primary schools in Victoria, Australia. Interview schedules were developed based on the theoretical domains framework (TDF). Interviews were coded using a framework analysis approach.

Findings

Four key themes emerged relating to ten of the 14 TDF domains. Themes included: knowledge, goals, implementation factors and leadership. School leaders play a central role in creating a positive implementation environment including the delivery setting (classroom) and a supportive culture (knowledge sharing) in the school. The application of the TDF to the study bridges the gap between theory and practice and identifies potential future implementation strategies which may be further tested in professional practice future studies. Recommendations for increased adoption and sustained implementation related to seven core areas: presence of a school/programme champion(s); collaborative knowledge sharing; online training; school-based workshops; promotion of behavioural and mental health outcomes; teacher autonomy in delivery; and a supportive implementation environment.

Originality/value

School leaders have a unique scope to influence the adoption and implementation of physical activity and sedentary behaviour interventions. This study outlines specific barriers and facilitators for implementation of a physical activity programme in the Australian educational setting and offers recommendations for programme optimisation.

Cross-Sectional Associations of Total Daily Volume and Activity Patterns across the Activity Spectrum with Cardiometabolic Risk Factors in Children and Adolescents

Sedentary and physical activity patterns (bouts/breaks) may be important for cardiometabolic health in early life. This study aimed to examine cross-sectional associations of total daily volume and patterns across the activity spectrum with cardiometabolic risk factors in youth aged 7-13 years. Objectively measured accelerometer and cardiometabolic risk factor data were pooled from two studies (n = 1219; 69% valid accelerometry). Total daily volume of sedentary time and light-, moderate-, and vigorous-intensity physical activity was determined. Time in sustained bouts and median bout lengths of all intensities and breaks in sedentary time were also calculated. Outcomes included body mass index, waist circumference, blood pressure, blood lipids, and a cardiometabolic summary score. Regression models revealed beneficial associations between total daily volumes of moderate- and vigorous-intensity physical activity and cardiometabolic risk. Time spent in ≥1 min vigorous-intensity physical activity bouts was beneficially associated with cardiometabolic risk, yet this disappeared after adjusting for total vigorous-intensity physical activity and confounders. Time accumulated in light- (≥1 min; ≥5 min) and moderate-intensity (≥1 min) physical activity bouts was detrimentally associated with cardiometabolic risk. Total daily volume and activity patterns may have implications for cardiometabolic risk early in life. Sporadic physical activity may be more beneficial for health than sustained physical activity.

Sedentary Behavior and Public Health: Integrating the Evidence and Identifying Potential Solutions

In developed and developing countries, social, economic, and environmental transitions have led to physical inactivity and large amounts of time spent sitting. Research is now unraveling the adverse public health consequences of too much sitting. We describe improvements in device-based measurement that are providing new insights into sedentary behavior and health. We consider the implications of research linking evidence from epidemiology and behavioral science with mechanistic insights into the underlying biology of sitting time. Such evidence has led to new sedentary behavior guidelines and initiatives. We highlight ways that this emerging knowledge base can inform public health strategy: First, we consider epidemiologic and experimental evidence on the health consequences of sedentary behavior; second, we describe solutions-focused research from initiatives in workplaces and schools. To inform a broad public health strategy, researchers need to pursue evidence-informed collaborations with occupational health, education, and other sectors.

Should We Scale-Up? A Mixed Methods Process Evaluation of an Intervention Targeting Sedentary Office Workers Using the RE-AIM QuEST Framework

Background: Interventions targeting a reduction in sedentary behaviour in office workers need to be scaled-up to have impact. In this study, the RE-AIM QuEST framework was used to evaluate the potential for further implementation and scale-up of a consultation based workplace intervention which targeted both the reduction, and breaking up of sitting time. Methods: To evaluate the Springfield College sedentary behaviour intervention across multiple RE-AIM QuEST indicators; intervention participant, non-participant (employees who did not participate) and key informant (consultation delivery team; members of the research team and stakeholders in workplace health promotion) data were collected using interviews, focus groups and questionnaires. Questionnaires were summarized using descriptive statistics and interviews and focus groups were transcribed verbatim, and thematically analysed. Results: Barriers to scale-up were: participant burden of activity monitoring; lack of management support; influence of policy; flexibility (scheduling/locations); time and cost. Facilitators to scale up were: visible leadership; social and cultural changes in the workplace; high acceptability; existing health and wellbeing programmes; culture and philosophy of the participating college. Conclusions: There is potential for scale-up, however adaptations will need to be made to address the barriers to scale-up. Future interventions in office workers should evaluate for scalability during the pilot phases of research.

The feasibility and impact of embedding pedagogical strategies targeting physical activity within undergraduate teacher education: Transform-Ed!

Purpose

Low levels of physical activity and high levels of sedentary behaviour are pervasive, especially in schools. Pre-service teacher education is pivotal to school and educational reform but is an under-studied setting for physical activity and sedentary behaviour intervention research. The objective of this pilot study was to test the feasibility and potential impact of embedding evidence-based active pedagogy based on an adapted version of Transform-Us!, Transform-Ed! in one core unit of an undergraduate teacher education degree.

Methods

Baseline and follow-up measures (i.e. surveys) were conducted with Bachelor of Education (Primary) pre-service teachers who received the Transform-Ed! intervention and academic educators who delivered the intervention. Focus groups of senior academics and telephone interviews with primary school principals examined perceptions of intervention feasibility and explored potential real-world relevance and impact of pre-service teachers training in active pedagogy.

Results

After 12 weeks, pre-service teachers (n = 218) were significantly more willing (pre–post change Δ = 0.54, 95% CI [0.16, 0.91]), confident (Δ = 1.40, 95% CI [0.89, 1.91]) and competent (Δ = 2.39, 95% CI [1.85, 2.92]) to deliver Transform-Ed!, had more positive feelings about the impact of physical activity on student outcomes (Δ = 2.05, 95% CI [1.58, 2.52]), and perceived fewer barriers to integrating Transform-Ed! into current and future teaching (Δ = − 7.26, 95% CI [− 8.88, − 5.64]). Four major themes emerged from the focus groups (n = 9) and interviews (n = 5) around participant perceptions of Transform-Ed!: (i) acceptability and appropriateness, (ii) need (tertiary level), (iii) need (primary level) and (iv) overcoming challenges.

Conclusion

The Transform-Ed! pilot study demonstrated promising results across multiple participant levels, as it was perceived to be feasible, acceptable and appropriate by pre-service teachers, academics and school principals. The findings have direct implications for the progression of Transform-Ed! from pilot to a future definitive trial.

Associations of Class-Time Sitting, Stepping and Sit-to-Stand Transitions with Cognitive Functions and Brain Activity in Children

Previous research showed that children’s physical activity is positively related to executive functions, whilst screen time shows negative associations. However, it is unclear how school-based sitting time and transitions from sitting to standing relate to cognition. We investigated the relationship between class time sitting/stepping/sit-to-stand transitions and cognitive functions in Grade 1–2 children. Overall, 149 children (7.7 ± 0.6 years old, 54% boys) participated. Measures included class time sitting/stepping/sit-to-stand transitions and: (i) response inhibition (i.e., response time and accuracy); (ii) lapses of attention; (iii) working memory; and (iv) brain activity (cortical haemodynamic response). Linear mixed-models, adjusting for age, sex, and clustering at the classroom level, found that more sitting time was associated with higher lapses of attention (β = 0.12, p < 0.05). Children who stepped more had quicker inhibition response time (β = −0.95, p < 0.01); however, they were less accurate in their responses (β = −0.30, p < 0.05) and this was also observed with sit-to-stand transitions (β = −0.26, p < 0.05). No associations were found with brain activity. In conclusion, reducing and breaking up sitting may help keep children focused, but the evidence regarding response inhibition is unclear.

Cost-effectiveness of community-based childhood obesity prevention interventions in Australia

OBJECTIVES

The objective of this study is to examine, from a limited societal perspective, the cost-effectiveness of community-based obesity prevention interventions (CBIs)-defined as a programme of community-level strategies to promote healthy eating and physical activity for Australian children (aged 5-18 years).

METHODS

The effectiveness of CBIs was determined by undertaking a literature review and meta-analysis. Commonly implemented strategies to increase physical activity and improve nutrition were costed (in 2010 Australian dollars) to determine the average cost of a generic programme. A multiple cohort Markov model that simulates diseases associated with overweight and obesity was used to estimate the health benefits, measured as health-adjusted life years (HALYs) and healthcare-related cost offsets from diseases averted due to exposure to the intervention. Health and cost outcomes were estimated over the lifetime of the target population. Monte-Carlo simulation was used to assess second-order uncertainty of input parameters to estimate mean incremental cost-effectiveness ratios (ICER) with 95% uncertainty intervals (UIs). Scenario analyses tested variations in programme intensity, target population, and duration of effect.

RESULTS

The meta-analysis revealed a small but significant difference in BMI z-score (mean difference of - 0.07 (95% UI: - 0.13 to - 0.01)) favouring the CBI community compared with the control. The estimated net cost of implementing CBIs across all local government areas (LGAs) in Australia was AUD426M (95% UI: AUD3M to AUD823M) over 3 years. This resulted in 51,792 HALYs gained (95% UI: 6816 to 96,972) over the lifetime of the cohort. The mean ICER was AUD8155 per HALY gained (95% UI: AUD237 to AUD81,021), with a 95% probability of being cost-effective at a willingness to pay threshold of AUD50,000 per HALY.

CONCLUSIONS

CBIs are cost-effective obesity prevention initiatives; however, implementation across Australia will be (relatively) expensive when compared with current investments in preventive health.

Stand Out in Class: restructuring the classroom environment to reduce sedentary behaviour in 9-10-year-olds - study protocol for a pilot cluster randomised controlled trial

Background

Sedentary behaviour (sitting) is a highly prevalent negative health behaviour, with individuals of all ages exposed to environments that promote prolonged sitting. Excessive sedentary behaviour adversely affects health in children and adults. As sedentary behaviour tracks from childhood into adulthood, the reduction of sedentary time in young people is key for the prevention of chronic diseases that result from excessive sitting in later life. The sedentary school classroom represents an ideal setting for environmental change, through the provision of sit-stand desks. Whilst the use of sit-stand desks in classrooms demonstrates positive effects in some key outcomes, evidence is currently limited by small samples and/or short intervention durations, with few studies adopting randomised controlled trial (RCT) designs. This paper describes the protocol of a pilot cluster RCT of a sit-stand desk intervention in primary school classrooms.

Methods/Design

A two-arm pilot cluster RCT will be conducted in eight primary schools (four intervention, four control) with at least 120 year 5 children (aged 9-10 years). Sit-stand desks will replace six standard desks in the intervention classrooms. Teachers will be encouraged to ensure all pupils are exposed to the sit-stand desks for at least 1 h/day on average using a rotation system. Schools assigned to the control arm will continue with their usual practice, no environmental changes will be made to their classrooms. Measurements will be taken at baseline, before randomisation, and at the end of the schools' academic year. In this study, the primary outcomes of interest will be school and participant recruitment and attrition, acceptability of the intervention, and acceptability and compliance to the proposed outcome measures (including activPAL-measured school-time and school-day sitting, accelerometer-measured physical activity, adiposity, blood pressure, cognitive function, academic progress, engagement, and behaviour) for inclusion in a definitive trial. A full process evaluation and an exploratory economic evaluation will also be conducted to further inform a definitive trial.

Discussion

The primary output of this study will be acceptability data to inform the development of a definitive cluster RCT designed to examine the efficacy of this intervention on health- and education-related outcomes in UK primary school children.

Trial registration

ISRCTN12915848 (retrospectively registered, date registered 9 November 2016).

Changes in Weight, Sedentary Behaviour and Physical Activity during the School Year and Summer Vacation

Background: To examine bidirectional associations between body weight and objectively assessed sedentary behaviour (SB) and physical activity (PA) during the school year and summer vacation. Methods: Participants were 209 Japanese boys and girls (9.0 ± 1.8 years at baseline). SB and PA were measured using triaxial accelerometry that discriminated between ambulatory and non-ambulatory PA, screen time measured by questionnaire during the school-term was evaluated in May and the summer vacation, and relative body weight measured in May and just after the end of summer vacation. Results: There were no significant relationships between changes in SB or PA and changes in body weight. However, higher relative body weight at baseline was associated with decreased non-ambulatory moderate PA (p = 0.049), but this association was slightly diminished after adjusting for change in SB (p = 0.056). Longer screen time at baseline was also associated with increased relative body weight (p = 0.033). Conclusions: The present study revealed that body weight might be particularly influential on non-ambulatory moderate PA while SB, PA or changes in these variables did not predict changes in body weight. Moreover, screen time during the school year is a predictor of change in relative body weight during the subsequent summer vacation.

Comparison of daily physical activity parameters using objective methods between overweight and normal-weight children

PURPOSE

The purpose of the present study was to determine if there were any differences in various aspects of physical activity such as energy expenditure, intensity, and type of activity between normal-weight and overweight boys.

METHODS

Children aged 9-12 years were recruited from 2 elementary schools located in different urban districts in Republic of Korea. The present study included 45 Korean boys, of which 19 were normal-weight and 26 were overweight. Daily physical activity was estimated over the same 1-week study period under free-living conditions using the doubly labeled water (DLW) method and a tri-axial accelerometer. Resting metabolic rate (RMR) was measured using the Douglas bag method and open-circuit indirect calorimetry. We calculated the physical activity level (PAL) as the total energy expenditure (TEE)/RMR.

RESULTS

PAL was not significantly different between the groups. In the accelerometer data, time spent in locomotive moderate-to-vigorous physical activity (MVPA) was significantly lower in overweight boys than in normal-weight subjects, whereas other variables including non-locomotive activity did not differ between groups. In addition, among all participants, time spent in total locomotive activity was significantly associated with PAL. Time spent in locomotive MVPA was significantly associated with PAL.

CONCLUSION

Overweight boys may be less physically active based on locomotive MVPA, which was positively related with PAL. Our findings suggest that the contribution of locomotive MVPA to the increase in PAL was relatively significant.

I Can Stand Learning: A Controlled Pilot Intervention Study on the Effects of Increased Standing Time on Cognitive Function in Primary School Children

Sedentarism is considered an independent cardiovascular risk factor. Thus, the present study investigated the effects of employing standing desks in classrooms on cognitive function. The intervention class (IG; n = 19) was supplied with standing desks and balance pads for 11 weeks. The control class (CG; n = 19) received lessons as usual. Standing time was assessed objectively (accelerometers) and subjectively (self-report sheets, external classroom observers). The impact of standing on the digit span task and Eriksen flanker task was analysed. The standing time of the IG was higher during the school day in comparison to the CG (lesson: p = 0.004; break: p = 0.003). The intra-class correlation coefficient between self-reports and external observation was high (ICC = 0.94). The IG improved slightly on the Digit Span Task compared to CG. Employing standing desks for at least 1 h per school day serves as a feasible and effective opportunity to improve cognitive function.

Study design and protocol for a mixed methods evaluation of an intervention to reduce and break up sitting time in primary school classrooms in the UK: The CLASS PAL (Physically Active Learning) Programme

INTRODUCTION

Children engage in a high volume of sitting in school, particularly in the classroom. A number of strategies, such as physically active lessons (termed movement integration (MI)), have been developed to integrate physical activity into this learning environment; however, no single approach is likely to meet the needs of all pupils and teachers. This protocol outlines an implementation study of a primary school-based MI intervention: CLASS PAL (Physically Active Learning) programme. This study aims to (A) determine the degree of implementation of CLASS PAL, (B) identify processes by which teachers and schools implement CLASS PAL and (C) investigate individual (pupil and teacher) level and school-level characteristics associated with implementation of CLASS PAL.

METHODS AND ANALYSIS

The intervention will provide teachers with a professional development workshop and a bespoke teaching resources website. The study will use a single group before-and-after design, strengthened by multiple interim measurements. Six state-funded primary schools will be recruited within Leicestershire, UK.Evaluation data will be collected prior to implementation and at four discrete time points during implementation: At measurement 0 (October 2016), school, teacher and pupil characteristics will be collected. At measurements 0 and 3 (June-July 2017), accelerometry, cognitive functioning, self-reported sitting and classroom engagement data will be collected. At measurements 1(December 2016-March 2017) and 3 , teacher interviews (also at measurement 4; September-October 2017) and pupil focus groups will be conducted, and at measurements 1 and 2 (April-May 2017), classroom observations. Implementation will be captured through website analytics and ongoing teacher completed logs.

ETHICS AND DISSEMINATION

Ethical approval was obtained through the Loughborough University Human Participants Ethics Sub-Committee (Reference number: R16-P115). Findings will be disseminated via practitioner and/or research journals and to relevant regional and national stakeholders through print and online media and dissemination event(s).

Standing Classrooms: Research and Lessons Learned from Around the World

Children spend between 50 and 70 % of their time sitting while at school. Independent of physical activity levels, prolonged sitting is associated with poor health outcomes in adulthood. While there is mixed evidence of health associations among children and adolescents, public health guidelines in the USA, UK, Australia and Canada now recommend young people should break up long periods of sitting as frequently as possible. A potentially effective approach for reducing and breaking up sitting throughout the day is changing the classroom environment. This paper presents an overview of a relatively new area of research designed to reduce youth sitting time while at school by changing the classroom environment (n = 13 studies). Environmental changes included placement of height-adjustable or stand-biased standing desks/workstations with stools, chairs, exercise balls, bean bags or mats in the classroom. These 13 published studies suggest that irrespective of the approach, youth sitting time was reduced by between ~44 and 60 min/day and standing time was increased by between 18 and 55 min/day during classroom time at school. Other benefits include increased energy expenditure and the potential for improved management of students' behaviour in the classroom. However, few large trials have been conducted, and there remains little evidence regarding the impact on children's learning and academic achievement. Nevertheless, with an increasing demand placed on schools and teachers regarding students' learning outcomes, strategies that integrate moving throughout the school day and that potentially enhance the learning experience and future health outcomes for young people warrant further exploration.

Proposed variations of the stepped-wedge design can be used to accommodate multiple interventions

OBJECTIVES

Stepped-wedge design (SWD) cluster-randomized trials have traditionally been used for evaluating a single intervention. We aimed to explore design variants suitable for evaluating multiple interventions in an SWD trial.

STUDY DESIGN AND SETTING

We identified four specific variants of the traditional SWD that would allow two interventions to be conducted within a single cluster-randomized trial: concurrent, replacement, supplementation, and factorial SWDs. These variants were chosen to flexibly accommodate study characteristics that limit a one-size-fits-all approach for multiple interventions.

RESULTS

In the concurrent SWD, each cluster receives only one intervention, unlike the other variants. The replacement SWD supports two interventions that will not or cannot be used at the same time. The supplementation SWD is appropriate when the second intervention requires the presence of the first intervention, and the factorial SWD supports the evaluation of intervention interactions. The precision for estimating intervention effects varies across the four variants.

CONCLUSION

Selection of the appropriate design variant should be driven by the research question while considering the trade-off between the number of steps, number of clusters, restrictions for concurrent implementation of the interventions, lingering effects of each intervention, and precision of the intervention effect estimates.

Effects of a Randomised Controlled School-Based Health Promotion Intervention on Obesity Related Behavioural Outcomes of Children with Migration Background

Children with migration background (MB) appear to be at higher risk of developing obesity, therefore, prevention is necessary to avoid possible health inequalities. This study investigated a 1-year intervention with focus on increasing physical activity (PA) and fruit and vegetable intake (FVI), decreasing screen media use (SMU) and soft drink consumption (SDC) in children with MB. 525 children (7.1 ± 0.7 years) with MB who participated in the cluster-randomised study were assessed at baseline and after 1 year. Daily SMU, PA behaviours, SDC and FVI were assessed using a parental questionnaire. After one year, significant effects were found in the intervention group for FVI (p ≤ 0.035). Partially strong tendencies but no significant differences were found for PA and SDC. Although the effects are small, the intervention seems to reach children with MB. An intervention lasting longer than one year might result in more changes.

An intervention to promote physical activity in Mexican elementary school students: building public policy to prevent noncommunicable diseases

Physical activity is an important component of strategies for health promotion and prevention of noncommunicable diseases. It is also associated with decreased risk for cardiovascular disease in overweight and obese adults and children. This article addresses the initial description of a physical activity intervention for children attending public elementary schools in Mexico. The objective was to develop a replicable model based on a strategic public, private, academic, and social partnership that would have a short-term impact on the metabolic health of children and be useful for building effective public policy. Forty-nine schools (20 000 students) participated, and 5 schools were selected for evaluation. The intervention included a 30-minute supervised middle-effort interchangeable routine, 5 days a week for a complete school year, adapted for different school conditions and students of different ages. Evaluation included anthropometric measurements and biochemical markers. Actual prevalence of combined overweight and obesity in these children was 31.9%. The intervention was successfully implemented in all schools. No change in body mass index, waist circumference, or other anthropometric indicators was found. However, changes in biochemical markers showed a significant decrease in blood glucose, total cholesterol, and cholesterol-low-density lipoproteins, reflecting a positive effect on cardiovascular health indicators.

A cluster-randomised controlled trial to promote physical activity in adolescents: the Raising Awareness of Physical Activity (RAW-PA) Study

Background

Recent technological advances provide an alternative yet underutilised opportunity for promoting physical activity in youth. The primary aim of the Raising Awareness of Physical Activity (RAW-PA) Study is to examine the short- and longer-term impact of a wearable activity monitor combined with digital behaviour change resources on adolescents’ daily physical activity levels.

Methods/Design

RAW-PA is a 12 week, multicomponent physical activity intervention that utilises a popular activity tracker (Fitbit® Flex) and supporting digital materials that will be delivered online via social media. The resources target key behaviour change techniques. The intervention structure and components have been informed by participatory research principles. RAW-PA will be evaluated using a cluster randomised controlled trial design with schools as the unit of randomisation. Twelve schools located in Melbourne, Australia, will allocated to either the intervention or wait-list control group. The target sample size is 300 Year 8 adolescents (aged 13–14 years). Participants’ moderate- to vigorous-intensity physical activity will be the primary outcome. Survey measures will be completed. Process factors (e.g. feasibility, acceptability/appeal, fidelity) will also be collected.

Discussion

To our knowledge, this study will provide some of the first evidence concerning the effect of wearable activity trackers and digital behaviour change resources on adolescents’ physical activity levels. This study will provide insights into the use of such technologies for physical activity promotion, which may have a significant impact on health education, promotion, practice and policy.

Trial registration

Australian and New Zealand Clinical Trials Registry No: ACTRN12616000899448. Date of registration: July 7, 2016.

Impact of an 8-Month Trial Using Height-Adjustable Desks on Children's Classroom Sitting Patterns and Markers of Cardio-Metabolic and Musculoskeletal Health

During school hours, children can sit for prolonged and unbroken periods of time. This study investigated the impact of an 8-month classroom-based intervention focusing on reducing and breaking-up sitting time on children’s cardio-metabolic risk factors (i.e., body mass index, waist circumference, blood pressure) and perceptions of musculoskeletal discomfort. Two Year-6 classes (24 students per class) in one primary school were assigned to either an intervention or control classroom. The intervention classroom was equipped with height-adjustable desks and the teacher was instructed in the delivery of pedagogical strategies to reduce and break-up sitting in class. The control classroom followed standard practice using traditional furniture. At baseline, and after 8-months, time spent sitting, standing, stepping, and sitting-bouts (occasions of continuous sitting) as well as the frequency of sit-to-stand transitions were obtained from activPAL inclinometers and the time spent in light-intensity physical activity was obtained from ActiGraph accelerometers. Demographics and musculoskeletal characteristics were obtained from a self-report survey. Hierarchical linear mixed models found that during class-time, children’s overall time spent sitting in long bouts (>10 min) were lower and the number of sit-to-stand transitions were higher in the intervention group compared to the control group, while no changes were observed for musculoskeletal pain/discomfort. No significant intervention effects were found for the anthropometrics measures and blood pressure. Height-adjustable desks and pedagogical strategies to reduce/break-up sitting can positively modify classroom sitting patterns in children. Longer interventions, larger and varied sample size may be needed to show health impacts; however, these desks did not increase musculoskeletal pain/discomfort.

Seasonal changes in objectively measured sedentary behavior and physical activity in Japanese primary school children

BACKGROUND

The recent prevalence of obesity in Japanese children is much higher compared to 1980. The present study compared daily sedentary behavior (SB) and physical activity (PA) between the school year and summer vacation in Japanese primary school children.

METHODS

Participants were 98 Japanese boys (8.9 ± 1.8 years at baseline) and 111 girls (9.1 ± 1.8 years). SB and PA were measured in May (school term) and July/August (summer vacation), 2011. SB and PA were assessed using a triaxial accelerometer (Active style Pro HJA-350IT, Omron Healthcare) for 7 consecutive days. The average number of minutes spent in SB (no more than 1.5 metabolic equivalents (METs)), light intensity activity (LPA; more than 1.5 to less than 3.0 METs) and moderate-to-vigorous physical activity (MVPA; 3.0 METs or more), and step counts were calculated for each individual. Moreover, the determinants/moderators of changes in SB and PA were examined.

RESULTS

Daily SB was significantly higher in the summer vacation than in the school year for both boys and girls (p < 0.05). Ambulatory and total LPA and MVPA, non-ambulatory LPA and step counts were lower in summer vacation in both genders (p < 0.001). Moreover, non-ambulatory MVPA was significantly lower in the summer vacation than in the school year for girls (p < 0.001). The decrease in non-ambulatory MVPA in boys and increase in SB in girls were significantly lower in those who participated in sports compared to those who did not (p < 0.040 or p < 0.033). The change in SB for boys was significantly associated with having a TV in the bedroom (p < 0.022).

CONCLUSIONS

These findings show that primary school children in Japan are less active in the summer vacation, as indicated by both higher SB and lower LPA and ambulatory MVPA in both genders. Moreover, the seasonal change in non-ambulatory MVPA for Japanese children was affected by gender. This study also suggests that sports participation and bedroom TV ownership may moderate seasonal changes in PA and SB. The results emphasize the need to take summer vacation into account when planning interventions aimed at decreasing SB or increasing PA in Japanese children.

A systematic review of the prevalence of sedentary behavior during the after-school period among children aged 5-18 years

BACKGROUND

Independent 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.

METHODS

A 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.

RESULTS

Twenty-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%).

CONCLUSION

Children 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 REGISTRATION

PROSPERO registration number CRD42015010437.

Sedentary behavior during school-time: Sociodemographic, weight status, physical education class, and school performance correlates in Brazilian schoolchildren

OBJECTIVES

To investigate whether sedentary behavior during school-time is associated with gender, age, mother's education, having physical education classes, weight status, and academic performance.

DESIGN

Cross-sectional study.

METHODS

A sample of 571 children (7-12 years old) from five elementary schools in Florianopolis, South Brazil had their height and weight measured, and wore accelerometers during class time. Teachers completed a form to evaluate children's reading and writing skills. Parents provided sociodemographic and educational information. Data was analyzed using multilevel linear regression analyses.

RESULTS

Children spent an average of 132min in sedentary behavior during school-time (64% of total school-time). Girls (137.5min), obese children (138.1min), older children (144.2min), and those who did not have physical education classes (140.2min) spent more time engaged in sedentary activities than their peers. Academic performance and mother's education were not associated with sedentary behaviors.

CONCLUSIONS

Children spent most of their school-time in sedentary activities, with girls, older students, and obese students being even more sedentary than their peers. Physical education classes were a protective factor against excessive sedentary behavior in school. Interventions for reducing sedentary behavior during school-time could employ additional strategies to benefit the at risk groups. In addition, encouraging student's participation in physical education classes could minimize the time spent in sedentary behavior during school hours.

Associations of sedentary time patterns and TV viewing time with inflammatory and endothelial function biomarkers in children

OBJECTIVE

Investigate associations of TV viewing time and accelerometry-derived sedentary time with inflammatory and endothelial function biomarkers in children.

METHODS

Cross-sectional analysis of 164 7-10-year-old children. TV viewing time was assessed by parental proxy report and total and patterns of sedentary time accumulation (e.g. prolonged bouts) were assessed by accelerometry. C-reactive protein (CRP), homeostasis model assessment of insulin resistance, interleukin-2, -6, -8, -10, tumour necrosis factor alpha, adiponectin, resistin, brain-derived neurotrophic factor, soluble intercellular and vascular adhesion molecule 1, plasminogen activator inhibitor 1 and soluble E-selectin were assessed. Generalised linear models assessed the associations of TV viewing and sedentary time with biomarkers, adjusting for sex, waist circumference, moderate- to vigorous-intensity physical activity and diet density.

RESULTS

Each additional h week(-1) of TV viewing was associated with 4.4% (95% CI: 2.1, 6.7) greater CRP and 0.6% (0.2, 1.0) greater sVCAM-1 in the fully adjusted model. The association between frequency and duration of 5-10 min bouts of sedentary time and CRP was positive after adjustment for sex and waist circumference but attenuated after adjustment for diet density.

CONCLUSIONS

This study suggests that TV viewing was unfavourably associated with several markers of inflammation and endothelial dysfunction. The detrimental association between 5 and 10 min bouts of sedentary time and CRP approached significance, suggesting that further research with a stronger study design (longitudinal and/or experimental) is needed to better understand how the accumulation of sedentary time early in life may influence short and longer term health.

Objectively measured sedentary behaviour and health and development in children and adolescents: systematic review and meta-analysis

Sedentary behaviour has emerged as a unique determinant of health in adults. Studies in children and adolescents have been less consistent. We reviewed the evidence to determine if the total volume and patterns (i.e. breaks and bouts) of objectively measured sedentary behaviour were associated with adverse health outcomes in young people, independent of moderate-intensity to vigorous-intensity physical activity. Four electronic databases (EMBASE MEDLINE, Ovid EMBASE, PubMed and Scopus) were searched (up to 12 November 2015) to retrieve studies among 2- to 18-year-olds, which used cross-sectional, longitudinal or experimental designs, and examined associations with health outcomes (adiposity, cardio-metabolic, fitness, respiratory, bone/musculoskeletal, psychosocial, cognition/academic achievement, gross motor development and other outcomes). Based on 88 eligible observational studies, level of evidence grading and quantitative meta-analyses indicated that there is limited available evidence that the total volume or patterns of sedentary behaviour are associated with health in children and adolescents when accounting for moderate-intensity to vigorous-intensity physical activity or focusing on studies with low risk of bias. Quality evidence from studies with robust designs and methods, objective measures of sitting, examining associations for various health outcomes, is needed to better understand if the overall volume or patterns of sedentary behaviour are independent determinants of health in children and adolescents.

The association between time spent in sedentary behaviors and blood pressure: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Sedentary behaviors, defined as waking behaviors with low energy expenditure while sitting, are positively associated with several adverse health outcomes. However, the association between sedentary behaviors and blood pressure (BP) is inconclusive. This study aimed to conduct a systematic review and meta-analysis on the association between time spent in sedentary behaviors and BP.

METHODS

We searched PubMed, MEDLINE, and Web of Science for papers published before August 2014 that assessed the association between time spent in sedentary behaviors and BP. Studies on both adults and children were included. Only good quality studies were included. The pooled estimates of systolic BP (SBP) and diastolic BP (DBP) increase per hour of time spent in sedentary behaviors a day were computed using a fixed-effects model and a random-effects model, respectively. Another pooled estimate of odds ratio per hour of time spent in sedentary behaviors a day on having high BP was computed using a fixed-effects model. A sub-group analysis was conducted for studies using self-reported and objectively assessed time spent in sedentary behaviors separately.

RESULTS

A total of 31 papers of good quality were included in the systematic review, 18 of which found no association between time spent in sedentary behaviors and BP (58.1%). A total of 28 papers were included in the meta-analysis. Pooled effects showed that an additional hour of time spent in sedentary behaviors per day was associated with an increase of 0.06 mmHg (108,228 participants, 95% CI 0.01-0.11, p = 0.01) of SBP and 0.20 mmHg (107,791 participants, 95% CI 0.10-0.29, p < 0.001) of DBP. Accelerometer-assessed time spent in sedentary behaviors was not associated with either SBP (p = 0.06) or DBP (p = 0.33). The odds ratio (OR) of having high BP with an additional hour of time spent in sedentary behaviors per day was 1.02 (98,798 participants, 95% CI 1.003-1.03, p = 0.02).

CONCLUSIONS

Self-reported but not accelerometer-assessed time spent in sedentary behaviors was associated with BP. Further studies are warranted to determine the preventive effect of reducing sedentary behaviors on high BP.

Determinants of changes in sedentary time and breaks in sedentary time among 9 and 12 year old children

The current study aimed to identify the determinants of objectively measured changes in sedentary time and sedentary fragmentation from age 9- to age 12 years. Data were collected as part of the Gateshead Millennium Birth Cohort study from September 2008 to August 2009 and from January 2012 to November 2012. Participants were 9.3 (± 0.4) years at baseline (n = 508) and 12.5 (± 0.3) years at follow-up (n = 427). Sedentary behaviour was measured using an ActiGraph GT1M accelerometer. Twenty potential determinants were measured, within a socio-ecological model, and tested for their association with changes in sedentary time and the extent to which sedentary behaviour is prolonged or interrupted (fragmentation index). Univariate and multivariate linear regression analyses were conducted. Measurements taken during winter and a greater decrease in moderate-to-vigorous intensity physical activity (MVPA) over time were associated with larger increases in sedentary time (seasonality β: - 3.03; 95% CI: - 4.52, - 1.54; and change in MVPA β: - 1.68; 95% CI: - 1.94, - 1.41). Attendance at sport clubs was associated with smaller increases in sedentary time (- 1.99; - 3.44, - 0.54). Girls showed larger decreases in fragmentation index (- 0.52; - 1.01, - 0.02). Interventions aimed at decreasing the decline in MVPA and increasing/maintaining sport club attendance may prevent the rise in sedentary time as children grow older. In addition, winter could be targeted to prevent an increase in sedentary time and reduction in sedentary fragmentation during this season.

Rationale and methods of a cluster-randomized controlled trial to promote active and healthy lifestyles among Brazilian students: the "Fortaleça sua Saúde" program

Background

Interventions on adolescents’ lifestyle are important, but the main mechanisms that explain the changes (mediating variables) on lifestyle are unclear. This paper presents the rationale and methods of an intervention program focused on promoting active and healthy lifestyles (especially physical activity [PA] practice and reducing screen time) among Brazilian students-the Fortaleça sua Saúde program (Portuguese for “strengthen your health”).

Methods/Design

This is a school-based cluster-randomized controlled trial. Three intervention and three control (no intervention) full-time public schools were randomly selected in Fortaleza, northeastern Brazil. Students (n = 1,272) from classes in Grades 7–9 were eligible, and 1,085 (548 in the intervention and 537 in control schools) completed the baseline and follow-up measures. The program duration was approximately four months and took place in 2014. Intervention strategies focused on teacher training, activities on health in the curriculum, active opportunities in the school environment (the availability of equipment for PA), and health education (health materials for students and parents). Data collection was undertaken before and immediately after the intervention. The primary variables included the practice of PA (weekly PA volume, PA behavior change stage and preference for PA during leisure-time) and screen time (TV and computer/video games). Potential intrapersonal, interpersonal and environmental mediators of PA and screen time were evaluated by a standardized questionnaire. Other lifestyle components (e.g., eating habits, substance use), psychological (e.g., self-rated health, body satisfaction) and biological (general and abdominal obesity) aspects, as well as academic performance were also evaluated in the total sample. Depressive symptoms, eating disorders, sleep quality, objectively-measured PA, and sedentary time were evaluated in obese students.

Discussion

If effective, this program will contribute to the development of public policies for the promotion of active and healthy lifestyles in youth, especially those from low- and middle-income countries. The main intrapersonal, interpersonal and/or environmental mediators of PA and screen time may also be indicated. Finally, we anticipate that the proposed strategies may be adaptable to public schools and may even be extended to the entire school system.

Trial registration

ClinicalTrials.Gov: NCT02439827. Registration date: May 3, 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2543-2) contains supplementary material, which is available to authorized users.