Principles for Adapting Assessments of Executive Function across Cultural Contexts.

Direct assessments of executive functions (EFs) are increasingly used in research and clinical settings, with a central assumption that they assess "universal" underlying skills. Their use is spreading globally, raising questions about the cultural appropriateness of assessments devised in Western industrialized countries. We selectively reviewed multidisciplinary evidence and theory to identify sets of cultural preferences that may be at odds with the implicit assumptions of EF assessments. These preferences relate to motivation and compliance; cultural expectations for interpersonal engagement; contextualized vs. academic thinking; cultural notions of speed and time; the willingness to be silly, be incorrect, or do the opposite; and subject-matter familiarity. In each case, we discuss how the cultural preference may be incompatible with the assumptions of assessments, and how future research and practice can address the issue. Many of the cultural preferences discussed differ between interdependent and independent cultures and between schooled and unschooled populations. Adapting testing protocols to these cultural preferences in different contexts will be important for expanding our scientific understanding of EF from the narrow slice of the human population that has participated in the research to date.

Inadequate Access to Potable Water Impacts Early Childhood Development in Low-Income Areas in Cape Town, South Africa.

Background: Water and sanitation are vital to human health and well-being. While these factors have been studied in relation to health, very little has been done to consider such environmental risk factors with child development. Here, we investigated possible relations between household water access/storage and early childhood development in four low-income settlements in the City of Cape Town, Western Cape province of South Africa. Our objectives were 1) to determine water access/storage practices in dwellings of children; 2) to assess early childhood development; and 3) and to understand the relationship between water access/storage practices in relation to early childhood development. Methods: We used a questionnaire to assess household water risk factors and the International Development and Early Learning Assessment (IDELA) tool to assess child early learning / cognitive, socio-emotional and motor development. Results: Mean age of the children (N = 192) was 4 years and 55% were female. The mean IDELA score was 48% (range: 36-54%) where the higher the score, the better the child's development. Around 70% of households had a tap inside their dwelling and half said that they stored water with the largest percentage of storage containers (21%) being plastic/no lid. Child IDELA scores were lower for children living in households that did not have an indoor tap and for households who stored water. Conclusions: Given the risks associated with climate change and the already poor conditions many children face regarding water and sanitation, research is needed to further investigate these relations to provide evidence to support appropriate interventions and ensure healthy child development.

Executive functioning skills and their environmental predictors among pre-school aged children in South Africa and The Gambia.

Executive functions (EFs) in early childhood are predictors of later developmental outcomes and school readiness. Much of the research on EFs and their psychosocial correlates has been conducted in high-income, minority world countries, which represent a small and biased portion of children globally. The aim of this study is to examine EFs among children aged 3-5 years in two African countries, South Africa (SA) and The Gambia (GM), and to explore shared and distinct predictors of EFs in these settings. The SA sample (N = 243, 51.9% female) was recruited from low-income communities within the Cape Town Metropolitan area. In GM, participants (N = 171, 49.7% female) were recruited from the rural West Kiang region. EFs, working memory (WM), inhibitory control (IC) and cognitive flexibility (CF), were measured using tablet-based tasks. Associations between EF task performance and indicators of socioeconomic status (household assets, caregiver education) and family enrichment factors (enrichment activities, diversity of caregivers) were assessed. Participants in SA scored higher on all EF tasks, but children in both sites predominantly scored within the expected range for their age. There were no associations between EFs and household or familial variables in SA, except for a trend-level association between caregiver education and CF. Patterns were similar in GM, where there was a trend-level association between WM and enrichment activities but no other relationships. We challenge the postulation that children in low-income settings have poorer EFs, simply due to lower socioeconomic status, but highlight the need to identify predictors of EFs in diverse, global settings. RESEARCH HIGHLIGHTS: Assessed Executive Functioning (EF) skills and their psychosocial predictors among pre-school aged children (aged 3-5 years) in two African settings (The Gambia and South Africa). On average, children within each setting performed within the expected range for their age, although children in South Africa had higher scores across tasks. There was little evidence of any association between socioeconomic variables and EFs in either site. Enrichment activities were marginally associated with better working memory in The Gambia, and caregiver education with cognitive flexibility in South Africa, both associations were trend-level significance.

Accelerometer-Measured Physical Activity and Sedentary Time among Children in Japan before and during COVID-19: A Cross-Sectional and Longitudinal Analysis.

This study examined changes in physical activity (PA), sedentary behavior (SB), screen time, sleep, and executive function among Japanese preschoolers between COVID-19 pre-pandemic and pandemic periods, using cross-sectional and longitudinal data. Accelerometer data from 63 children aged 5-6 years were collected from three kindergartens in Tokyo, Japan, in late 2019 (pre-COVID-19). This was compared to the data of 49 children aged 5-6 years from the same kindergartens, collected in late 2020 (during COVID-19). Sixteen children in the pre-COVID-19 cohort also participated in the 2020 survey and provided data for the longitudinal analysis. The mean minutes of PA, SB, screen time, and sleep duration, as well as executive function, were compared between the pre- and during COVID-19 cohorts. After adjusting for school, sex, and accelerometer wear time, there were no significant differences in any of the measured outcomes between the two cohorts. However, the analysis of longitudinal data revealed significant increases in time spent in SB and on screens, and a decrease in light-intensity PA and sleep duration during the pandemic compared to the pre-pandemic period. Results suggest that, despite the COVID-19 pandemic, young children's activity levels and SB did not significantly differ from pre-pandemic levels. However, school-aged children's SB, light PA, and sleep time were affected, although this cannot be disentangled from the effects of the transition to school.

Effects of Cognitively Engaging Physical Activity on Preschool Children's Cognitive Outcomes.

Research combining physical activity with the training of cognitive skills such as executive functions is emerging as a novel and fruitful intervention approach for children. Purpose: This study aimed to examine the impact of an intervention program including cognitively engaging physical activity on preschool children's cognitive outcomes and physical activity. Methods: Children (N = 144, 65 female; Mage = 4.41 years, SD = 0.61), randomly assigned to one of three groups: cognitively engaging physical activity (CPA; i.e., storytelling, cognitive activities, and motor tasks, n = 55), cognition (i.e., storytelling and cognitive activities without motor tasks, n = 48), or control (i.e., traditional storytelling, n = 41). Sessions lasted approximately 17 minutes, conducted twice a week, for 6 weeks. Children's executive function, self-regulation, and related outcomes (i.e., numeracy) were assessed at baseline and again-along with perceived enjoyment-at the end of the program. Accelerometers measured children's physical activity during each session. Teachers completed a logbook for each session, and two fidelity checks per preschool took place by the researcher. Main analyses used linear mixed models adjusted for covariates (age, sex) and clustering at the preschool level. Results: Results showed no significant group by time interaction for executive function, self-regulation, numeracy, enjoyment. During the sessions, children in the CPA group were more physically active than children in the cognition and control groups. Conclusion: While we did not find the expected amplified cognitive benefits, making storytelling more active has the potential to meet two needs (increase cognitive stimulation and physical activity levels) in one deed.

Parent perspectives on young children's changing digital practices: Insights from Covid-19.

Young children's use of digital technologies has presented challenges for parents, particularly in response to an increased reliance on digital resources during the Covid-19 pandemic. This mixed-methods study explored young children's digital practices within the context of their families and homes. Although this study was originally planned, the timing of data collection meant that it was uniquely positioned to capture parent perspectives as the pandemic and first lockdown was unfolding in Australia. Data was collected through questionnaire (N = 101) and semistructured interview (n = 20) about status and change in children's digital practices, and parents' rules and flexibility in governing these experiences. Quantitative findings suggested children's frequency and duration of digital device use trended upwards during lockdown, and parents were more flexible in their rules about the amount of screen time, as well as when and where children could use digital devices. Qualitative results suggested that, more than a temporary and situational change, for many parents, exposure to new ways of engaging with digital technologies facilitated a shift in their perceptions, leading to greater consideration of quality in their choices for their children. This study highlights the influential role of parents in shaping children's digital experiences. Understanding their perceptions, as well as children's current and shifting digital practices in the home, is important for informing efforts and guidance for supporting young children's safe and effective use of digital technologies.

Child exposure to violence and self-regulation in South African preschool-age children from low-income settings.

Biological and psychosocial stressors that have been associated with income include family dynamics such as household chaos, family conflict, maternal depression, harsh parenting, lower parental responsiveness, and exposure to violence. Research from high income countries has shown that exposure to violence may have detrimental effects on children's self-regulation, with possible flow-on implications for broad later-life outcomes, but less is known about such links in low- and- middle income countries, where many children live in violent communities and households and where physical punishment remains the norm. This study aimed to investigate exposure to violence, in addition to coercive parenting, and its associations with self-regulation among 243 3- to 5-year-olds (M = 4.7 ± 0.6; 51.9 % female) from low-income settings in Cape Town and who were not attending Early Childhood Care and Education (ECCE). Results showed that self-regulation was not associated with child exposure to community violence, but it was positively associated with coercive parenting (ß = 0.17; p = 0.03). The null concurrent associations between exposure to violence and self-regulation suggest the need for additional research aimed at understanding later potential developmental sequelae. It is important that findings regarding coercive parenting are contextualised within local social norms around parenting styles, as well as the influence of living in dangerous communities on parenting practices.

A Systematic Scoping Review of Pre-School Self-Regulation Interventions from a Self-Determination Theory Perspective.

Self-regulation (SR) is considered foundational in early life, with robust evidence demonstrating a link between early self-regulation and longer-term outcomes. This has been the impetus for a growing body of intervention research into how best to support early SR development, yet approaches and effects are diverse, which complicates an understanding of the critical characteristics for effective early SR intervention. Using Self-Determination Theory (SDT) as a guiding framework, we present a scoping review of early SR-intervention research to identify the characteristics of pre-school interventions that show significant and strong effects on young children's SR. Studies from peer-reviewed journal articles were included if they evaluated a SR intervention with pre-school children, were published between 2010 and 2020, written in English, and included a SR outcome measure. This yielded 19 studies, each reporting the efficacy of a different SR intervention. Results showed that content factors (what interventions do) interacted with their implementation (how, when, and by whom interventions are implemented) to discriminate the more versus less efficacious interventions. Through the lens of SDT, results further suggested that targeting competence through encouragement and feedback, and nurturing children's autonomy distinguished more from less effective interventions. Relatedness was least able to discriminate intervention efficacy.

Improving quality of teaching and child development: A randomised controlled trial of the leadership for learning intervention in preschools.

Introduction: Substantial research indicates that high quality early childhood education and care (ECEC) confers a wide range of benefits for children, yet quality in ECEC remains inconsistent. Given the variability in training and qualifications, one strategy for improving ECEC quality is in-service professional development (PD). Methods: The current study evaluated an evidence-based in-service PD programme, Leadership for Learning, via a cluster randomised controlled trial involving 83 ECEC services and 1,346 children in their final year of pre-school. Results: Results indicated significant improvements in teaching quality across treatment centres and child development outcomes in language, numeracy and social-emotional development. Discussion: This study provides strong support for making evidence-informed PD routinely available for ECEC practitioners.

Executive Function and Self-Regulation: Bi-Directional Longitudinal Associations and Prediction of Early Academic Skills.

Despite a tendency to study executive function (EF) and self-regulation (SR) separately, parallel lines of research suggest considerable overlap between the two abilities. Specifically, both show similar developmental trajectories (i.e., develop rapidly in the early years), predict a broad range of overlapping outcomes across the lifespan (e.g., academic success, mental and physical health, and social competence), and have overlapping neural substrates (e.g., prefrontal cortex). While theoretical frameworks diverge in how they reconcile EF and SR - ranging from treating the two as functionally synonymous, to viewing them as related yet distinct abilities - there is no consensus and limited empirical evidence on the nature of their relationship and how this extends developmentally. The current study examined bi-directional longitudinal associations between early EF and SR, and their longitudinal associations with subsequent early academic skills, in a sample of 199 3- to 5-year-old pre-school children. The adopted measures permitted EF and SR to be modelled as composite indices for these analyses, thereby decreasing task-specific components of these associations. Early academic skills were captured by a standardized direct assessment. Bi-directional associations between EF and SR were found, with both accounting for unique variance in early academic skills 7 and 19months later. The current results provide important evidence to distinguish between EF and SR abilities, yet also for their reciprocal influence in situ and across early development.

Effect of Omega-3 Supplementation on Self-Regulation in Typically Developing Preschool-Aged Children: Results of the Omega Kid Pilot Study-A Randomised, Double-Blind, Placebo-Controlled Trial.

Supplementation of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) may enhance self-regulation (SR) and executive functioning (EF) in children of preschool age. The aim of the Omega Kid Study was to investigate the effect of n-3 LCPUFA supplementation on SR and EF in typically developing preschool-aged children. A double-blind placebo-controlled pilot trial was undertaken, the intervention was 12 weeks and consisted of 1.6 g of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per day compared to placebo. The HS-Omega-3 Index® was assessed by capillary blood samples at baseline and post-intervention. Seventy-eight children were enrolled and randomised to either the n-3 LCPUFA treatment (n = 39) or placebo (n = 39) group. Post intervention, there was a significant three-fold increase in the HS-Omega-3 Index® in the n-3 LCPUFA group (p < 0.001). There were no improvements in SR or EF outcome variables for the n-3 LCPUFA group post intervention compared to the placebo group determined by linear mixed models. At baseline, there were significant modest positive Spearman correlations found between the HS-Omega-3 index® and both behavioural self-regulation and cognitive self-regulation (r = 0.287, p = 0.015 and r = 0.242, p = 0.015 respectively). Although no treatment effects were found in typically developing children, further research is required to target children with sub-optimal self-regulation who may benefit most from n-3 LCPUFA supplementation.

Cross-Sectional Associations of Application Use and Media Program Viewing with Cognitive and Psychosocial Development in Preschoolers.

Executive functions and psychosocial health during childhood are positively associated with health and developmental outcomes into adulthood. Electronic media use has been reported to adversely affect health and development in children; however, what remains unclear is whether contemporary media behaviors, such as electronic application (app) use, exerts similar effects on health and development. We investigated the associations of electronic media use (program viewing and app use) with cognitive and psychosocial development in preschoolers. Parents of preschool children (n = 247, 4.2 ± 0.6 years) reported the time their child spent using electronic media. Direct assessment of the children's executive functions (working memory, inhibition, and shifting) and educator-reported psychosocial difficulties were also collected. Associations were examined using linear regression adjustments for covariates and preschool clustering. Small, but significant, negative associations were observed for total electronic media use (b = -0.001; 95% CI: -0.003, -0.000; p = 0.026) and program viewing (b = -0.002; 95% CI: -0.003, -0.000; p = 0.033) with children's visual-spatial working memory. However, high-dose app users demonstrated higher phonological working memory scores compared to non-users (MD = 0.31; 95% CI: 0.04, 0.58; p = 0.025). Similarly, compared to non-users, low-dose app users displayed statistically significantly fewer total difficulties (MD = -1.67; 95% CI: -3.31, -0.02; p = 0.047). No associations were evident for high-dose app users and the remaining outcomes. The results may suggest that attempts to reduce program viewing while promoting moderate levels of app use may exert positive influences on children's executive functions and psychosocial development.

The Feasibility of the "Omega Kid" Study Protocol: A Double-Blind, Randomised, Placebo-Controlled Trial Investigating the Effect of Omega-3 Supplementation on Self-Regulation in Preschool-Aged Children.

Self-regulation, the regulation of behaviour in early childhood, impacts children's success at school and is a predictor of health, wealth, and criminal outcomes in adulthood. Self-regulation may be optimised by dietary supplementation of omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs). The aim of the "Omega Kid" study is to investigate the feasibility of a protocol to investigate whether n-3 LCPUFA supplementation enhances self-regulation in preschool-aged children. The protocol assessed involved a double-blind, randomised, placebo-controlled trial of 12 weeks duration, with an intervention of 1.6 g of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per day (0.3 g EPA and 1.3 g DHA) in a microencapsulated powder compared to placebo. Children (n = 78; 40 boys and 38 girls) aged 3-5 years old were recruited and randomly allocated to the treatment (n = 39) or placebo group (n = 39). The HS-Omega-3 Index® served as a manipulation check on the delivery of either active (n-3 LCPUFAs) or placebo powders. Fifty-eight children (76%) completed the intervention (28-30 per group). Compliance to the study protocol was high, with 92% of children providing a finger-prick blood sample at baseline and high reported-adherence to the study intervention (88%). Results indicate that the protocol is feasible and may be employed in an adequately powered clinical trial to test the hypothesis that n-3 LCPUFA supplementation will improve the self-regulation of preschool-aged children.

Longitudinal associations of physical activity and modified organized sport participation with executive function and psychosocial health in preschoolers.

To examine the longitudinal associations of objectively measured physical activity and modified organized sport participation with executive functions and psychological health in preschoolers. One hundred and eighty-five preschool children, mean age 4.2 ± 7.68; (years:months), 34% girls were followed for one year. Physical activity was measured using accelerometery, examining light, moderate, vigorous, moderate-to-vigorous, and total physical activity. Parents reported children's participation in modified organized sport. Direct assessment of children's executive functions (working memory, inhibition and shifting) and educator-reported psychosocial difficulties were also collected. Associations were examined using linear regression adjusting for covariates, baseline developmental outcomes and preschool clustering. Vigorous physical activity at baseline was positively associated with children's shifting performance (b = 0.245; 95% CI: 0.006, 0.485, p =.045) at follow-up, while the association for moderate-to-vigorous physical activity approached significance (b = 0.119; 95% CI: -0.001, 0.239, p =.051). Children not participating in modified organized sport at baseline demonstrated better inhibition scores 12-months later compared to sports participants (Mdiff 0.06; CI: 0.00, 0.13, p =.046). Increasing time spent in higher intensity physical activity among preschool children may be a viable target for supporting their later cognitive development, although there was no clear benefit of early participation in modified organized sport.

Promoting Physical Activity and Executive Functions Among Children: A Cluster Randomized Controlled Trial of an After-School Program in Australia.

BACKGROUND: The aim of this study was to examine the efficacy of an embedded after-school intervention, on promoting physical activity and academic achievement in primary-school-aged children. METHODS: This 6-month, 2-arm cluster randomized controlled trial involved 4 after-school centers. Two centers were randomly assigned to the intervention, which involved training the center staff on and implementing structured physical activity (team sports and physical activity sessions for 75 min) and academic enrichment activities (45 min). The activities were implemented 3 afternoons per week for 2.5 hours. The control centers continued their usual after-school care practice. After-school physical activity (accelerometry) and executive functions (working memory, inhibition, and cognitive flexibility) were assessed pre- and postintervention. RESULTS: A total of 60 children were assessed (7.7 [1.8] y; 50% girls) preintervention and postintervention (77% retention rate). Children in the intervention centers spent significantly more time in moderate to vigorous physical activity (adjusted difference = 2.4%; 95% confidence interval, 0.6 to 4.2; P = .026) and scored higher on cognitive flexibility (adjusted difference = 1.9 units; 95% confidence interval, 0.9 to 3.0; P = .009). About 92% of the intervention sessions were implemented. The participation rates varied between 51% and 94%. CONCLUSION: This after-school intervention was successful at increasing moderate to vigorous physical activity and enhancing cognitive flexibility in children. As the intervention was implemented by the center staff and local university students, further testing for effectiveness and scalability in a larger trial is required.

Proximal and distal predictors of self-regulatory change in children aged 4 to 7 years.

BACKGROUND: Growth in early self-regulation skills has been linked to positive health, wellbeing, and achievement trajectories across the lifespan. While individual studies have documented specific influences on self-regulation competencies in early childhood, few have modelled a comprehensive range of predictors of self-regulation change across health, development, and environment simultaneously. This study aimed to examine the concurrent associations among a range of proximal and distal influences on change in children's self-regulation skills over 2 years from age 4-5 years. METHODS: Data from the Longitudinal Study of Australian Children (N = 4983) were used in a structural equation model, predicting a multi-source composite measure of self-regulation at each of 4-5 years and 6-7 years. By controlling for earlier self-regulation and covariates, the model examined the relative contributions of a comprehensive range of variables to self-regulation change including health, development, educational, home environment, time-use, and neighbourhood characteristics. RESULTS: The significant predictors of children's self-regulation growth across 4 to 7 years were fewer behavioural sleep problems, higher gross motor and pre-academic skills, lower levels of maternal and paternal angry parenting, and lower levels of financial hardship. There were also marginal effects for high-quality home learning environments and child-educator relationships. CONCLUSION: Findings suggest that if we are to successfully foster children's self-regulation skills, interventionists would do well to operate not only on children's current capacities but also key aspects of their surrounding context.

Compliance with the 24-Hour movement guidelines for the early years: Cross-sectional and longitudinal associations with executive function and psychosocial health in preschool children.

OBJECTIVE: To examine whether meeting the Australian 24-Hour Movement Guidelines was associated with cognitive and psychosocial health in preschoolers. DESIGN: Prospective observational study. METHODS: Cross-sectional (n=247) and 12-month longitudinal (n=185) data from the PATH-ABC study were examined. Physical activity was assessed by accelerometry. Parents reported children's screen time and sleep. Children were categorised at baseline as meeting: i) none/one guideline, ii) two guidelines, or iii) 24-Hour Movement Guidelines. Associations with executive functions and psychosocial health were examined using linear regression, adjusting for covariates and preschool clustering. Longitudinal associations were additionally adjusted for baseline levels of development. RESULTS: High proportions of children met the physical activity (94.3%) and sleep (89.9%) guidelines, 17.8% and 17.4% met screen time and 24-Hour Movement Guidelines, respectively. Cross-sectionally, children meeting both sleep and physical activity guidelines displayed better phonological working memory (p=0.026) and shifting (p= 0.034) scores compared to children who did not. Meeting two (p=0.037) and three (p=0.017) guidelines were associated with better phonological working memory and shifting scores, respectively (vs. meeting 0/1 guideline). Longitudinally, children meeting the physical activity guideline at baseline displayed better shifting performance 12-months later compared to those who did not (p<0.002). No associations with remaining cognitive outcomes, and no associations with psychosocial outcomes were evident. CONCLUSIONS: Null associations suggest that meeting the recommendations may not be adequate for broad cognitive and psychosocial health outcomes in preschoolers. However, supporting preschool children to meet the physical activity and sleep guidelines, may be beneficial for aspects of cognitive health.

Everyday Practices and Activities to Improve Pre-school Self-Regulation: Cluster RCT Evaluation of the PRSIST Program.

The Preschool Situational Self-Regulation Toolkit (PRSIST) Program was developed as a low-cost and embedded approach for educators to foster pre-schoolers' self-regulation and related abilities (e.g., executive function, school readiness). This study reports on a cluster RCT study with 50 Australian pre-school services to evaluate the effectiveness of the PRSIST Program for improving children's self-regulation, executive function and school readiness, compared to current routine practice. Pre-school centers were recruited to reflect the breadth of geography, pedagogical quality, and socio-economic catchment areas across the early childhood education and care sector. All children identified as in their final year of pre-school education at these centers were invited to participate, resulting in a sample of 473 3-5-year-old children at baseline. Centers were randomly assigned to groups after baseline data collection, and data collectors were blinded to group assignment throughout the study. It was hypothesized that engagement in the PRSIST Program would improve children's self-regulation, executive function and school readiness, over and above normal age-related rates of development. Results indicated small but significant improvements in executive functioning for the intervention group, after adjusting for cluster, baseline results and key covariates. All other outcomes were descriptively in favor of the intervention group but failed to reach significance. Levels of use of the program remained high by most educators throughout the intervention period, suggesting its acceptability and sustainability within these contexts. Together, results show promise for this approach to self-regulation development. Opportunities that might further strengthen this approach are discussed. This study was registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12617001568303) and study protocols published in advance of commencement. Funding for this study was provided by the Australian Research Council's Discovery Early Career Researcher Award research grant scheme.

'Jump start' childcare-based intervention to promote physical activity in pre-schoolers: six-month findings from a cluster randomised trial.

BACKGROUND: Participation in adequate levels of physical activity during the early years is important for health and development. We report the 6-month effects of an 18-month multicomponent intervention on physical activity in early childhood education and care (ECEC) settings in low-income communities. METHODS: A cluster randomised controlled trial was conducted in 43 ECEC settings in disadvantaged areas of New South Wales, Australia. Three-year-old children were recruited and assessed in the first half of 2015 with follow-up 6 months later. The intervention was guided by Social Cognitive Theory and included five components. The primary outcome was minutes per hour in total physical activity during ECEC hours measured using Actigraph accelerometers. Intention-to-treat analysis of the primary outcome was conducted using a generalized linear mixed model. RESULTS: A total of 658 children were assessed at baseline. Of these, 558 (85%) had valid accelerometer data (mean age 3.38y, 52% boys) and 508 (77%) had valid accelerometry data at 6-month follow-up. Implementation of the intervention components ranged from 38 to 72%. There were no significant intervention effects on mins/hr. spent in physical activity (adjusted difference = - 0.17 mins/hr., 95% CI (- 1.30 to 0.97), p = 0.78). A priori sub-group analyses showed a greater effect among overweight/obese children in the control group compared with the intervention group for mins/hr. of physical activity (2.35mins/hr., [0.28 to 4.43], p = 0.036). CONCLUSIONS: After six-months the Jump Start intervention had no effect on physical activity levels during ECEC. This was largely due to low levels of implementation. Increasing fidelity may result in higher levels of physical activity when outcomes are assessed at 18-months. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12614000597695.