Evaluation of the Effectiveness of a Whole-System Intervention to Increase the Physical Activity of Children Aged 5 to 11 Years (Join Us: Move Play, JU:MP): Protocol for a Quasiexperimental Trial.

BACKGROUND: Daily physical activity is vital for the health and development of children. However, many children are inactive. Previous attempts to achieve sustained increases in daily physical activity in children have been ineffective. Join Us: Move Play (JU:MP) is a whole-system, complex, community-based intervention aiming to increase the physical activity levels of children aged 7 to 11 years who live in areas of Bradford, England, which are multicultural and have high levels of deprivation. OBJECTIVE: The purpose of this quasiexperimental controlled trial is to assess whether the JU:MP program increases primary school children's physical activity. METHODS: The study has a 2-arm, quasiexperimental, nonblinded, nonequivalent group design and will be conducted with primary school children aged 5 to 11 years at 3 timepoints, including baseline (before intervention), 24 months (during intervention), and 36 months (after intervention). Children attending primary schools within the intervention area will be invited to participate. Children attending similar schools within similar neighborhoods based on school and community census demographics (deprivation, free school meals, and ethnicity) outside of the JU:MP geographical area will be invited to participate in the control condition. At each timepoint, consenting participants will wear an accelerometer for 7 consecutive days (24 hours a day) to measure the primary outcome (average daily moderate-to-vigorous physical activity). Multivariable mixed effects linear regression will be applied to estimate differences in the primary outcome between the 2 arms at 24 months and 36 months on an intention-to-treat basis. The secondary outcome analysis will explore changes in socioemotional well-being (teacher reported), quality of life (parental/carer reported), and other contextual factors (parents/carer reported), as well as segments of the day activity, sleep, sedentary screen time, frequency of places to be active, parent practices (nondirective support and autonomy support), social cohesion, and neighborhood walking/exercise environment. RESULTS: Recruitment occurred from July 2021 to March 2022, and baseline data were collected from September 2021 to March 2022. As of March 2022 (end of baseline data collection), a total of 1454 children from 37 schools (17 intervention schools and 20 control schools) have been recruited. The first follow-up data collection will occur from September 2023 to March 2024, and the second and final follow-up data collection will occur from September 2024 to March 2025. Data analysis has not begun, and the final results will be published in December 2025. CONCLUSIONS: This article describes the protocol for a quasiexperimental controlled trial examining a novel whole-system intervention. TRIAL REGISTRATION: ISRCTN ISRCTN14332797; https://www.isrctn.com/ISRCTN14332797. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/43619.

A whole system approach to increasing children's physical activity in a multi-ethnic UK city: a process evaluation protocol.

BACKGROUND: Engaging in regular physical activity requires continued complex decision-making in varied and dynamic individual, social and structural contexts. Widespread shortfalls of physical activity interventions suggests the complex underlying mechanisms of change are not yet fully understood. More insightful process evaluations are needed to design and implement more effective approaches. This paper describes the protocol for a process evaluation of the JU:MP programme, a whole systems approach to increasing physical activity in children and young people aged 5-14 years in North Bradford, UK. METHODS: This process evaluation, underpinned by realist philosophy, aims to understand the development and implementation of the JU:MP programme and the mechanisms by which JU:MP influences physical activity in children and young people. It also aims to explore behaviour change across wider policy, strategy and neighbourhood systems. A mixed method data collection approach will include semi-structured interview, observation, documentary analysis, surveys, and participatory evaluation methods including reflections and ripple effect mapping. DISCUSSION: This protocol offers an innovative approach on the use of process evaluation feeding into an iterative programme intended to generate evidence-based practice and deliver practice-based evidence. This paper advances knowledge regarding the development of process evaluations for evaluating systems interventions, and emphasises the importance of process evaluation.

Covid-19 lockdown: Ethnic differences in children's self-reported physical activity and the importance of leaving the home environment; a longitudinal and cross-sectional study from the Born in Bradford birth cohort study.

BACKGROUND: In England, the onset of COVID-19 and a rapidly increasing infection rate resulted in a lockdown (March-June 2020) which placed strict restrictions on movement of the public, including children. Using data collected from children living in a multi-ethnic city with high levels of deprivation, this study aimed to: (1) report children's self-reported physical activity (PA) during the first COVID-19 UK lockdown and identify associated factors; (2) examine changes of children's self-reported PA prior to and during the first UK lockdown. METHODS: This study is part of the Born in Bradford (BiB) COVID-19 Research Study. PA (amended Youth Activity Profile), sleep, sedentary behaviours, daily frequency/time/destination/activity when leaving the home, were self-reported by 949 children (9-13 years). A sub-sample (n = 634) also self-reported PA (Physical Activity Questionnaire for Children) pre-pandemic (2017-February 2020). Univariate analysis assessed differences in PA between sex and ethnicity groups; multivariable logistic regression identified factors associated with children's PA. Differences in children's levels of being sufficiently active prior to and during the lockdown were examined using the McNemar test; and multivariable logistic regression was used to identify factors explaining change. RESULTS: During the pandemic, White British (WB) children were more sufficiently active (34.1%) compared to Pakistani Heritage children (PH) (22.8%) or 'Other' ethnicity children (O) (22.8%). WB children reported leaving the home more frequently and for longer periods than PH and O children. Modifiable variables related to being sufficiently active were frequency, duration, type of activity, and destination away from the home environment. There was a large reduction in children being sufficiently active during the first COVID-19 lockdown (28.9%) compared to pre-pandemic (69.4%). CONCLUSIONS: Promoting safe extended periods of PA everyday outdoors is important for all children, in particular for children from ethnic minority groups. Children's PA during the first COVID-19 UK lockdown has drastically reduced from before. Policy and decision makers, and practitioners should consider the findings in order to begin to understand the impact and consequences that COVID-19 has had upon children's PA which is a key and vital behaviour for health and development.

The Acceptability, Feasibility, and Effectiveness of Wearable Activity Trackers for Increasing Physical Activity in Children and Adolescents: A Systematic Review.

Wearable activity trackers (wearables) embed numerous behaviour change techniques (BCTs) that have previously been shown to increase adult physical activity (PA). With few children and adolescents achieving PA guidelines, it is crucial to explore ways to increase their PA. This systematic review examined the acceptability, feasibility, and effectiveness of wearables and their potential mechanisms of action for increasing PA in 5 to 19-year-olds. A systematic search of six databases was conducted, including data from the start date of each database to December 2019 (PROSPERO registration: CRD42020164506). Thirty-three studies were included. Most studies (70%) included only adolescents (10 to 19 years). There was some-but largely mixed-evidence that wearables increase steps and moderate-to-vigorous-intensity PA and reduce sedentary behaviour. There were no apparent differences in effectiveness based on the number of BCTs used and between studies using a wearable alone or as part of a multi-component intervention. Qualitative findings suggested wearables increased motivation to be physically active via self-monitoring, goal setting, feedback, and competition. However, children and adolescents reported technical difficulties and a novelty effect when using wearables, which may impact wearables' long-term use. More rigorous and long-term studies investigating the acceptability, feasibility, and effectiveness of wearables in 5 to 19-year-olds are warranted.

Stand Out in Class: Investigating the Potential Impact of a Sit-Stand Desk Intervention on Children's Sitting and Physical Activity during Class Time and after School.

Sedentary behaviour (sitting) is a risk factor for adverse health outcomes. The classroom environment has traditionally been associated with prolonged periods of sitting in children. The aim of this study was to examine the potential impact of an environmental intervention, the addition of sit-stand desks in the classroom, on school children's sitting and physical activity during class time and after school. The 'Stand Out in Class' pilot trial was a two-arm cluster randomised controlled trial conducted in eight primary schools with children from a mixed socioeconomic background. The 4.5 month environmental intervention modified the physical (six sit-stand desks replaced standard desks) and social (e.g., teachers' support) environment. All children wore activPAL and ActiGraph accelerometers for 7 days at baseline and follow-up. In total 176 children (mean age = 9.3 years) took part in the trial. At baseline, control and intervention groups spent more than 65% of class time sitting, this changed to 71.7% and 59.1% at follow-up, respectively (group effect p < 0.001). The proportion of class time spent standing and stepping, along with the proportion of time in light activity increased in the intervention group and decreased in the control group. There was no evidence of any compensatory effects from the intervention after school. Incorporating sit-stand desks to change the classroom environment at primary school appears to be an acceptable strategy for reducing children's sedentary behaviour and increasing light activity especially during class time. Trial registration: ISRCTN12915848 (registered: 09/11/16).

Impacts of a Standing Desk Intervention within an English Primary School Classroom: A Pilot Controlled Trial.

Traditional classroom furniture dictates that children predominantly sit during class time. This study evaluated the impact of providing standing desks within a deprived UK primary school setting over 8 months using mixed-method approaches. All children within a Year 5 class (9-10-year-olds, n = 30) received an adjustable sit-stand desk, while another Year 5 class (n = 30) in a nearby school retained traditional furniture as a control classroom. At baseline, 4 months, and 8 months, activPAL monitors (PAL Technologies, Glasgow, UK) were worn for 7 days to provide time spent sitting and standing. Behavior-related mental health, musculoskeletal discomfort surveys, and a cognitive function test battery were also completed at all three timepoints. Intervention experiences from pupils and the teacher were captured using focus groups, interviews, and classroom observations. At both 4 months and 8 months, multi-level models revealed a reduction in class time sitting in the intervention group compared to the control group ((ß (95%CI) 4 months -25.3% (-32.3, -18.4); 8 months -19.9% (-27.05, -12.9)). Qualitative data revealed challenges to teaching practicalities and a gradual decline in behavior-related mental health was observed (intervention vs. control: 4 months +5.31 (+2.55, +8.08); 8 months +7.92 (+5.18, +10.66)). Larger trials within similar high-priority settings are required to determine the feasibility and cost-effectiveness of providing standing desks to every child in the classroom.

Stand Out in Class: restructuring the classroom environment to reduce sitting time - findings from a pilot cluster randomised controlled trial.

BACKGROUND: Excessive sedentary behaviour (sitting) is a risk factor for poor health in children and adults. Incorporating sit-stand desks in the classroom environment has been highlighted as a potential strategy to reduce children's sitting time. The primary aim of this study was to examine the feasibility of conducting a cluster randomised controlled trial (RCT) of a sit-stand desk intervention within primary school classrooms. METHODS: We conducted a two-armed pilot cluster RCT involving 8 primary schools in Bradford, United Kingdom. Schools were randomised on a 1:1 basis to the intervention or usual practice control arm. All children (aged 9-10 years) in participating classes were eligible to take part. Six sit-stand desks replaced three standard desks (sitting 6 children) in the intervention classrooms for 4.5-months. Teachers were encouraged to use a rotation system to ensure all pupils were exposed to the sit-stand desks for > 1 h/day on average. Trial feasibility outcomes (assessed using quantitative and qualitative measures) included school and participant recruitment and attrition, intervention and outcome measure completion rates, acceptability, and preliminary effectiveness of the intervention for reducing sitting time. A weighted linear regression model compared changes in weekday sitting time (assessed using the activPAL accelerometer) between trial arms. RESULTS: School and child recruitment rates were 33% (n = 8) and 75% (n = 176). At follow-up, retention rates were 100% for schools and 97% for children. Outcome measure completion rates ranged from 63 to 97%. A preliminary estimate of intervention effectiveness revealed a mean difference in change in sitting of - 30.6 min/day (95% CI: - 56.42 to - 4.84) in favour of the intervention group, after adjusting for baseline sitting and wear time. Qualitative measures revealed the intervention and evaluation procedures were acceptable to teachers and children, except for some problems with activPAL attachment. CONCLUSION: This study provides evidence of the acceptability and feasibility of a sit-stand desk intervention and evaluation methods. Preliminary evidence suggests the intervention showed potential in reducing children's weekday sitting but some adaptations to the desk rotation system are needed to maximize exposure. Lessons learnt from this trial will inform the planning of a definitive trial. TRIAL REGISTRATION: ISRCTN12915848 (registered: 09/11/16).

Using a multi-stakeholder experience-based design process to co-develop the Creating Active Schools Framework.

BACKGROUND: UK and global policies recommend whole-school approaches to improve childrens' inadequate physical activity (PA) levels. Yet, recent meta-analyses establish current interventions as ineffective due to suboptimal implementation rates and poor sustainability. To create effective interventions, which recognise schools as complex adaptive sub-systems, multi-stakeholder input is necessary. Further, to ensure 'systems' change, a framework is required that identifies all components of a whole-school PA approach. The study's aim was to co-develop a whole-school PA framework using the double diamond design approach (DDDA). METHODOLOGY: Fifty stakeholders engaged in a six-phase DDDA workshop undertaking tasks within same stakeholder (n = 9; UK researchers, public health specialists, active schools coordinators, headteachers, teachers, active partner schools specialists, national organisations, Sport England local delivery pilot representatives and international researchers) and mixed (n = 6) stakeholder groupings. Six draft frameworks were created before stakeholders voted for one 'initial' framework. Next, stakeholders reviewed the 'initial' framework, proposing modifications. Following the workshop, stakeholders voted on eight modifications using an online questionnaire. RESULTS: Following voting, the Creating Active Schools Framework (CAS) was designed. At the centre, ethos and practice drive school policy and vision, creating the physical and social environments in which five key stakeholder groups operate to deliver PA through seven opportunities both within and beyond school. At the top of the model, initial and in-service teacher training foster teachers' capability, opportunity and motivation (COM-B) to deliver whole-school PA. National policy and organisations drive top-down initiatives that support or hinder whole-school PA. To the authors' knowledge, this is the first time practitioners, policymakers and researchers have co-designed a whole-school PA framework from initial conception. The novelty of CAS resides in identifying the multitude of interconnecting components of a whole-school adaptive sub-system; exposing the complexity required to create systems change. The framework can be used to shape future policy, research and practice to embed sustainable PA interventions within schools. To enact such change, CAS presents a potential paradigm shift, providing a map and method to guide future co-production by multiple experts of PA initiatives 'with' schools, while abandoning outdated traditional approaches of implementing interventions 'on' schools.

Objectively-measured sedentary time and physical activity in a bi-ethnic sample of young children: variation by socio-demographic, temporal and perinatal factors.

BACKGROUND: Evidence suggests that South Asian school-aged children and adults are less active compared to the white British population. It is unknown if this generalises to young children. We aimed to describe variability in levels of physical activity and sedentary time in a bi-ethnic sample of young children from a deprived location. METHODS: This observational study included 202 South Asian and 140 white British children aged 1.5 to 5y, who provided 3181 valid days of triaxial accelerometry (Actigraph GT3X+). Variability in sedentary time and physical activity levels were analysed by linear multilevel modelling. Logistic multilevel regression was used to identify factors associated with physical inactivity (failing to perform ≥180 min of total physical activity including ≥60 min moderate-to-vigorous physical activity (MVPA) per day). RESULTS: There were no significant ethnic differences in the overall levels of behaviours; South Asian and white British children spent half of daily time sedentary, just over 40% in light physical activity, and the remaining 7.5 to 8% of time in MVPA. Sedentary time was lower and physical activity levels were higher in older children, and levels of MVPA and vector magnitude counts per minute (CPM) were higher on weekends compared to weekdays. In South Asian children, sedentary time was lower on weekends. Sedentary time was lower and physical activity levels were higher in spring compared to winter in white British children, and in all seasons compared to winter in South Asian children. South Asian children born at high birth weight performed more MVPA, and in both ethnicities there was some evidence that children with older mothers were more sedentary and less active. Sedentary time was higher and light physical activity was lower in South Asian children in the highest compared to the lowest income families. South Asian girls performed less MVPA, registered fewer vector magnitude CPM, and were 3.5 times more likely to be physically inactive than South Asian boys. CONCLUSIONS: Sedentary time and physical activity levels vary by socio-demographic, temporal and perinatal characteristics in young children from a deprived location. South Asian girls have the most to gain from efforts to increase physical activity levels. TRIAL REGISTRATION: The Pre-schoolers in the Playground (PiP) pilot randomized controlled trial is registered with the ISRCTN (ISRCTN54165860; http://www.isrctn.com).

Maternal Physical Activity and Neonatal Cord Blood Lipid Levels: Findings From a Prospective Pregnancy Cohort.

BACKGROUND: Physical activity performed while pregnant is beneficially associated with maternal cardiovascular health. It is unknown if benefits extend to neonatal cardiovascular health. This study investigated associations of maternal physical activity with neonatal cord blood lipid and lipoprotein concentrations. METHODS: Cord blood lipids were measured at birth in a pseudorandomly selected subgroup of Born in Bradford birth cohort participants (N = 1634). Pregnant women were grouped into 4 activity categories (inactive/somewhat active/moderately active/active) based on their self-reported physical activity at 26- to 28-weeks gestation. Regression was used to calculate adjusted mean differences in neonatal cord blood lipid concentrations among the 4 groups of physical activity. RESULTS: Maternal physical activity was associated with higher neonatal cord blood high-density lipoprotein cholesterol. Cord blood high-density lipoprotein cholesterol was higher in neonates of women who were somewhat and moderately active compared with neonates of women who were inactive. There were no associations of pregnancy physical activity with triglycerides, low-density lipoprotein, very low-density lipoprotein cholesterol, or adiponectin levels. CONCLUSIONS: Maternal physical activity is favorably associated with neonatal cord blood high-density lipoprotein cholesterol levels. This novel beneficial finding highlights the potential for physical activity in pregnancy to aid the early prevention of cardiovascular disease.

Associations of Pregnancy Physical Activity with Maternal Cardiometabolic Health, Neonatal Delivery Outcomes and Body Composition in a Biethnic Cohort of 7305 Mother-Child Pairs: The Born in Bradford Study.

OBJECTIVE: Physical activity is advocated for a range of benefits to the uncomplicated pregnancy. We investigated associations of mid-pregnancy physical activity with maternal and neonatal health in white British and Pakistani-origin women from a deprived urban setting. METHODS: The study was performed in 6921 pregnant women (53% Pakistani-origin) who contributed data for 7305 singleton births. At 26-28 weeks gestation, women were grouped into four activity levels (inactive/somewhat active/moderately active/active) based on their self-reported physical activity. Linear regression with robust standard errors was used to calculate adjusted mean differences in health markers between the four groups of physical activity (reference group: inactive). RESULTS: Three-quarters (74%) of Pakistani-origin women and 39% of white British women were inactive. Trend-tests revealed that more active white British women tended to be less adipose, had lower fasting and postload glucose levels, lower triglyceride concentrations, and their babies were less adipose (smaller triceps and subscapular skinfolds) than less active white British women. Somewhat active Pakistani-origin women exhibited lower triglyceride concentrations and systolic blood pressure, higher high-density lipoprotein cholesterol levels, and their babies were less adipose (smaller mid-upper arm and abdominal circumferences; lower cord-blood leptin concentration) compared to inactive Pakistani-origin women. No associations were observed for gestational age or birth weight. CONCLUSIONS: Physical activity performed mid-pregnancy was beneficially associated with maternal cardiometabolic health and neonatal adiposity, without influencing gestational age or birth weight. Associations were dose-dependent in white British women, and even a small amount of mid-pregnancy physical activity appeared to benefit some health markers in Pakistani-origin women.

Growing up in Bradford: protocol for the age 7-11 follow up of the Born in Bradford birth cohort.

BACKGROUND: Born in Bradford (BiB) is a prospective multi-ethnic pregnancy and birth cohort study that was established to examine determinants of health and development during childhood and, subsequently, adult life in a deprived multi-ethnic population in the north of England. Between 2007 and 2010, the BiB cohort recruited 12,453 women who experienced 13,776 pregnancies and 13,858 births, along with 3353 of their partners. Forty five percent of the cohort are of Pakistani origin. Now that children are at primary school, the first full follow-up of the cohort is taking place. The aims of the follow-up are to investigate the determinants of children's pre-pubertal health and development, including through understanding parents' health and wellbeing, and to obtain data on exposures in childhood that might influence future health. METHODS: We are employing a multi-method approach across three data collection arms (community-based family visits, school based physical assessment, and whole classroom cognitive, motor function and wellbeing measures) to follow-up over 9000 BiB children aged 7-11 years and their families between 2017 and 2021. We are collecting detailed parent and child questionnaires, cognitive and sensorimotor assessments, blood pressure, anthropometry and blood samples from parents and children. Dual x-ray absorptiometry body scans, accelerometry and urine samples are collected on subsamples. Informed consent is collected for continued routine data linkage to health, social care and education records. A range of engagement activities are being used to raise the profile of BiB and to disseminate findings. DISCUSSION: Our multi-method approach to recruitment and assessment provides an efficient method of collecting rich data on all family members. Data collected will enhance BiB as a resource for the international research community to study the interplay between ethnicity, socioeconomic circumstances and biology in relation to cardiometabolic health, mental health, education, cognitive and sensorimotor development and wellbeing.

Ethnic differences in sedentary behaviour in 6-8-year-old children during school terms and school holidays: a mixed methods study.

BACKGROUND: Sedentary behaviour (SB) in childhood is a major public health concern. Little is known about ethnic differences in SB during school and holiday weeks among White British (WB) and South Asian (SA) children, which this study aims to address through investigating inclinometer measured SB and exploring reasons for child engagement in SB. METHODS: A mixed methods study, comprising of a quantitative investigation with 160, 6-8 years old children and a qualitative study with a subsample of 18 children, six parents and eight teachers was undertaken. Children of WB and SA ethnicity in three schools were invited to wear inclinometers for seven school terms (summer/winter/spring) and seven holidays (winter/spring) days during July 2016-May 2017. Total SB, SB accumulated in bouts > 30 min and breaks in SB were explored using multivariate linear mixed effects models which adjusted for wear time, sex, deprivation, overweight status, season, term, weekday and school. Nine focus groups and two interviews were carried out using the Theoretical Domains Framework to explore SB perceptions among parents, teachers and children. Data were analysed using the Framework Approach. RESULTS: 104/160 children provided 836 valid days of data. Children spent on average eight hours of SB/day during term time and holidays, equating to 60% of their awake time, and had on average 111 SB breaks /day. SA children had 25 fewer SB breaks/ day when compared to WB (p < 0.001). Perceived reasons for engagement in SB included: boredom, enjoyment of screen activities (by children), parenting practices, curriculum pressures (by teachers), the need to sit down and learn, and child's preference for screen activities (by parents). CONCLUSIONS: Children spent 60% of their awake time being sedentary, regardless of ethnicity or school term. There were no significant ethnic differences for any of the SB outcomes except for breaks in SB. Interventions aimed at reducing SB should consider involving parents and teachers and should focus on increasing breaks in SB, especially for SA children, who are at a higher risk of cardio metabolic ill health.

activPAL-measured sitting levels and patterns in 9-10 years old children from a UK city.

BACKGROUND: There is insufficient evidence of sitting time in UK children from validated objective measures. This study explored sitting patterns in primary school children from Bradford, UK, using the validated activPAL inclinometer. METHODS: Overall, 79 children (9.8 (SD 0.3) years old, 52% boys; 70% South Asian) wore activPALs for 7 days. Total sitting time, sitting time accumulated in different bout lengths, and the proportion of wear time spent in these variables were explored and compared across different periods of the week. RESULTS: Children spent 614 ± 112 (median ± IQR) min/day on school days and 690 ± 150 min/day on weekend days sitting. The proportion of time spent sitting was significantly higher on weekend days compared to school days (mean±SD: 74 ± 10% versus 68 ± 8%,P < 0.001), as was the proportion of time accumulated in >30 min sitting bouts (mean±CI: 28 ± 27-33% versus 20 ± 20-22%, P < 0.001). The proportion of time spent sitting after school was significantly higher than during school time (mean±SD: 70 ± 8.4% versus 63 ± 8.3%,P < 0.001), as was the proportion of time spent in prolonged (>30 min) sitting bouts (mean±CI: 19 ± 16-22% versus 11 ± 10-14%, P < 0.001). CONCLUSIONS: Children spent large proportions of their waking day sitting, often accumulated in prolonged uninterrupted bouts and particularly after school and on weekends. Interventions to reduce sitting time in children are urgently needed.

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).

Profiling Movement and Gait Quality Characteristics in Pre-School Children.

There is a dearth of suitable metrics capable of objectively quantifying motor competence. Further, objective movement quality characteristics during free play have not been investigated in pre-school children. The aims of this study were to characterize children's free play physical activity and investigate how gait quality characteristics cluster with free play in pre-school children (3-5 years old). Sixty-one children (39 boys; 4.3 ± 0.7 years, 1.04 ± 0.05 m, 17.8 ± 3.2 kg) completed the movement assessment battery for children and took part in free play while wearing an ankle- and hip-mounted accelerometer. Characteristics of movement quality were profiled using a clustering algorithm. Spearman's rho and the Mann-Whitney U tests were used to assess relationships between movement quality characteristics and motor competence classification differences in integrated acceleration and spectral purity, respectively. Significant differences were found between motor competency classifications for spectral purity and integrated acceleration (p < .001). Spectral purity was hierarchically clustered with motor competence and integrated acceleration. Significant positive correlations were found between spectral purity, integrated acceleration and motor competence (p < .001). This is the first study to report spectral purity in pre-school children and the results suggest that the underlying frequency component of movement is clustered with motor competence.

Prevalence, trajectories, and determinants of television viewing time in an ethnically diverse sample of young children from the UK.

BACKGROUND: Excessive screen viewing in early childhood is associated with poor physical and psycho-social health and poor cognitive development. This study aimed to understand the prevalence, trajectory and determinants of television viewing time in early childhood to inform intervention development. METHODS: In this prospective longitudinal study, mothers of 1558 children (589 white British, 757 Pakistani heritage, 212 other ethnicities) completed questionnaires when their children were approximately 6, 12, 18, 24 and 36 months old. Mothers answered questions about their own and their child's TV-time. TV-time trajectories were estimated by linear longitudinal multilevel modeling, potential determinants were considered in models. RESULTS: The modelled trajectory estimated that 75% of children aged 12 months exceeded guidelines of zero screen-time. At 12 months of age an accelerated increase in TV-time was observed (<1 h/day at 14 months, >2 h/day by 30 months old). For every hour of mothers' TV-time and every hour the TV was on in the home, children's TV-time was 8 min and 1 min higher respectively at 6 months old (P < 0.05), and 15 min and 3 min higher respectively at 36 months old (P < 0.05). Children whose mothers did not agree that it was important their child did not watch too much TV, had 17 min more TV-time than their counterparts (P < 0.05). Children of first time mothers had 6 min more TV-time (P < 0.05). At 12 months of age, children of mothers experiencing stress watched 8 min more TV (P < 0.05). By 36 months, children of Pakistani heritage mothers had 22 min more TV-time than those of white British mothers (P < 0.05), and an additional 35 min of TV-time if their mother was not born in the UK (P < 0.05). CONCLUSIONS: High levels of TV-time were prevalent. Intervention developers should consider targeting interventions before 12 months of age. Modifiable determinants included mothers' own TV-time, the time the television is on in the home and mothers' attitude towards child TV-time. These behaviours may be key components to address in interventions for parents. Mothers experiencing stress, first time mothers, and Pakistani heritage mothers (particularly those born outside of the UK), may be priority groups for intervention.

Sleep Duration and Adiposity in Early Childhood: Evidence for Bidirectional Associations from the Born in Bradford Study.

Study Objectives: To examine independent associations of sleep duration with total and abdominal adiposity, and the bidirectionality of these associations, in a young biethnic sample of children from a disadvantaged location. Methods: Child sleep duration (h/day) was parent-reported by questionnaire and indices of total (body weight, body mass index, percent body fat (%BF), sum of skinfolds) and abdominal adiposity (waist circumference) were measured using standard anthropometric procedures at approximately 12, 18, 24, and 36 months of age in 1,338 children (58% South Asian; 42% White). Mixed effects models were used to quantify independent associations (expressed as standardised ß-coefficients (95% confidence interval (CI)) of sleep duration with adiposity indices using data from all four time-points. Factors considered for adjustment in models included basic demographics, pregnancy and birth characteristics, and lifestyle behaviours. Results: With the exception of the sum of skinfolds, sleep duration was inversely and independently associated with indices of total and abdominal adiposity in South Asian children. For example, one standard deviation (SD) higher sleep duration was associated with reduced %BF by -0.029 (95% CI: -0.053, -0.0043) SDs. Higher adiposity was also independently associated with shorter sleep duration in South Asian children (for example, %BF: ß = -0.10 (-0.16, -0.028) SDs). There were no significant associations in White children. Conclusions: Associations between sleep duration and adiposity are bidirectional and independent among South Asian children from a disadvantaged location. The results highlight the importance of considering adiposity as both a determinant of decreased sleep and a potential consequence.