Physical activity guidelines for preschoolers: a call for research to inform public health policy

Active Commuting to School among Spanish Preschool Children: A Temporal Change Study between 2013 and 2017

BACKGROUND

Active commuting to school may increase the total daily physical activity and achieve health benefits among preschool children. Rates of active commuting to school among Spanish children and adolescents have been widely analysed, while the rates of active commuting to school among Spanish preschool children are unknown.

AIM

The main objective of this study was to examine the changes in the rates of active commuting to school in a sample of Spanish preschool children between 3 and 6 years old from 2013 to 2017.

METHODS

Data were found from five studies carried out across Spain. The study sample comprised 4787 preschool children (4.59 ± 0.77 years old; 51% males). The overall changes in active commuting to school were assessed using multilevel logistic regression analysis.

RESULTS

The rates of active commuting to school in Spanish preschool children are around 52%, and the active commuting to school rates have stayed stable throughout the period assessed (odds ratio from 0.40 to 0.58, all p > 0.05).

CONCLUSION

In preschool children, the present study obtained a favourable result on active commuting to school, showing a pattern stability in the examined period similar to other ages. It will be of great importance to promote this behaviour to obtain high levels of active commuting to school.

Understanding cross-data dynamics of individual and social/environmental factors through a public health lens: explainable machine learning approaches

Introduction

The rising prevalence of obesity has become a public health concern, requiring efficient and comprehensive prevention strategies.

Methods

This study innovatively investigated the combined influence of individual and social/environmental factors on obesity within the urban landscape of Seoul, by employing advanced machine learning approaches. We collected 'Community Health Surveys' and credit card usage data to represent individual factors. In parallel, we utilized 'Seoul Open Data' to encapsulate social/environmental factors contributing to obesity. A Random Forest model was used to predict obesity based on individual factors. The model was further subjected to Shapley Additive Explanations (SHAP) algorithms to determine each factor's relative importance in obesity prediction. For social/environmental factors, we used the Geographically Weighted Least Absolute Shrinkage and Selection Operator (GWLASSO) to calculate the regression coefficients.

Results

The Random Forest model predicted obesity with an accuracy of >90%. The SHAP revealed diverse influential individual obesity-related factors in each Gu district, although 'self-awareness of obesity', 'weight control experience', and 'high blood pressure experience' were among the top five influential factors across all Gu districts. The GWLASSO indicated variations in regression coefficients between social/environmental factors across different districts.

Conclusion

Our findings provide valuable insights for designing targeted obesity prevention programs that integrate different individual and social/environmental factors within the context of urban design, even within the same city. This study enhances the efficient development and application of explainable machine learning in devising urban health strategies. We recommend that each autonomous district consider these differential influential factors in designing their budget plans to tackle obesity effectively.

Optimising the effects of physical activity on mental health and wellbeing: A joint consensus statement from Sports Medicine Australia and the Australian Psychological Society

OBJECTIVES

This consensus statement from Sports Medicine Australia and the Australian Psychological Society aims to provide guidance to practitioners on the ways that physical activity can be promoted to maximise benefits to mental health.

METHODS

Following the Clinical Consensus Statement protocol, an expert group comprised of eight members with expertise in physical activity and mental health articulated recommendations regarding five physical activity contextual factors: type, physical environment, delivery, domain, and social environment.

RESULTS

To optimise the mental health benefits of physical activity, we recommend: i) activity selection be guided by factors associated with adherence and enjoyment as opposed to any specific type (type); ii) facilitators (i.e., teachers, coaches, instructors, practitioners) deliver organised physical activity sessions using an instructional style that satisfies individuals' basic needs for autonomy, competence and social connection (delivery); iii) participation in physical activity with others who provide support, facilitate positive interactions, or make people feel valued, so long as it does not undermine a preference to be active alone (social environment); iv) where possible and appropriate, some physical activity should be undertaken outside in pleasant natural environments (physical environment); and, v) at least some physical activity be undertaken during leisure-time or via active travel, where possible prioritising activities one personally chooses to undertake (domain).

CONCLUSIONS

The type, domain, physical and social environment of physical activity, as well as the way in which it is delivered, will determine mental health outcomes. Practitioners can use these recommendations to optimise the effects of physical activity on mental health.

Movement behavior policies in the early childhood education and care setting: An international scoping review

Background

Meeting 24-h movement behavior guidelines for the early years is associated with better health and development outcomes in young children. Early childhood education and care (ECEC) is a key intervention setting however little is known about the content and implementation of movement behavior polices in this context. To inform policy development this international scoping review examined the prevalence, content, development and implementation of ECEC-specific movement behavior policies.

Methods

A systematic literature search of published and gray literature since 2010 was conducted. Academic databases (EMBASE, Cinahl, Web of Science, Proquest, Scopus, EBSCO, PubMed) were searched. A Google search was undertaken and limited to the first 200 results. The Comprehensive Analysis of Policy on Physical Activity framework informed data charting.

Results

Forty-three ECEC policy documents met inclusion criteria. Most policies originated in the United States, were subnational and developed with government, non-government organizations and ECEC end-users. Physical activity was specified in 59% (30-180 min/day), sedentary time in 51% (15-60 min/day) and sleep in 20% (30-120 min/day) of policies. Daily outdoor physical activity was recommended (30-160 min/day) in most policies. No policy permitted screen time for children <2 years, with 20-120 min/day for children >2 years. Most policies (80%) had accompanying resources but few provided evaluation tools (e.g., checklists; action plan templates). Many policies had not been reviewed since the publication of 24-h movement guidelines.

Conclusion

Movement behavior policies in the ECEC setting are often vaguely worded, missing a comprehensive evidence base, siloed in development and often not tailored for the 'real world.' A focus on evidence informed ECEC-specific movement behavior policies proportionally aligned with national/international 24-h Movement Behaviors Guidelines for the Early Years is needed.

Clinical practice guidelines for the prevention of childhood obesity: A systematic review of quality and content

Obesity in childhood is a significant global issue, and prevention is key to reducing prevalence. Healthcare providers can play an important role in the prevention of obesity. The aim of this systematic review was to identify and evaluate clinical practice guidelines (CPGs) for preventing childhood obesity with a focus on the role of medical doctors. Peer-reviewed literature and gray literature sources were searched for CPGs published from 2010 to 2021. Eleven CPGs were identified. Quality was evaluated using the Appraisal of Guidelines for Research and Evaluation Collaboration (AGREE II) instrument; seven CPGs were higher quality and four lower quality. Recommendations within the CPGs covered three main areas: growth monitoring, maintaining a healthy weight, and managing overweight. The importance of involving the whole family and healthy lifestyle behaviors was emphasized. The majority of the CPGs rated poorly in guideline applicability highlighting the need for practical implementation tools. Although our review identified a number of CPGs relevant to the prevention of obesity for doctors working with children and their families, more research is needed to produce high-quality meaningful and applicable CPGs to maximize uptake, implementation, and ultimately, benefit to children and their families.

Physical Activity Opportunities in US Early Child Care Programs

BACKGROUND AND OBJECTIVES

Physical activity provides health and developmental benefits to young children. The Study of Nutrition and Activity in Child Care Settings describes physical activity opportunities and sedentary occasions for children aged 1 to 5 years at programs participating in the US Department of Agriculture Child and Adult Care Food Program.

METHODS

The Study of Nutrition and Activity in Child Care Settings obtained a nationally representative sample of classrooms within Child and Adult Care Food Program-participating Head Start and child care centers via multistage cluster sampling. For 1 observation day, an observer in each classroom tallied designated outdoor and indoor playspaces; minutes children spent in playspaces; barriers and facilitators to physical activity; and classroom time when most children were physically active (eg, walking, dancing), sedentary (seated, lying down), or neither. Weighted descriptive tabulations by program type compared outdoor physical activity opportunity counts and total physical activity opportunity durations to national guidelines. Multivariate regression analysis investigated association of barriers with physical activity opportunity duration.

RESULTS

The sample included 227 classrooms, 96 in child care centers and 131 in Head Start programs. All had sedentary occasions outside meals, snacks, and naps; virtually all offered opportunities for physical activity. Seventy-four percent of programs met national guidance on sufficient number of outdoor opportunities, weather permitting. Just 50% met guidance of ≥60 to 90 minutes of physical activity, whereas only 43% met both sets of guidance. Weather and staff not joining in outdoor play were associated with 74 and 31 fewer minutes devoted to physical activity, respectively.

CONCLUSIONS

Findings suggest ample room for improvement in provision of physical activity opportunities during child care.

Parent-perceived neighbourhood environment, parenting practices and preschool-aged children physical activity and screen time: a cross-sectional study of two culturally and geographically diverse cities

BACKGROUND

Preschool-aged children's physical activity (PA) and screen time (ST) are important health-related behaviours likely influenced by PA opportunities, parental perceptions of neighbourhood safety and parenting practices pertaining to PA and ST. How these factors interact to impact on young children's PA and ST, and whether their effects are generalisable across cultures and geographical location is not known. This study addressed these knowledge gaps by conducting pooled analyses of comparable data from two culturally and geographically diverse samples - Chinese parent-child dyads from an ultra-dense city (Hong Kong, China) and Latino parent-child dyads from a low-density city (Houston, USA).

METHODS

The analytical sample consisted of 164 Hong Kong Chinese and 84 US Latino parent-child dyads with data on socio-demographic characteristics, parent-perceived neighbourhood destinations and facilities for children's PA, physical and social safety-related neighbourhood attributes, PA-related parenting practices and child's ST and accelerometer-assessed PA. Generalised linear models with robust standard errors accounting for neighbourhood-level clustering were used to estimate associations and interaction effects.

RESULTS

Hong Kong Chinese children accumulated less PA than US Latino children, although the latter had more ST. Hong Kong Chinese parents reported more parenting practices promoting inactivity. Neighbourhood PA opportunities were positively related to children's PA only if parental perceptions of neighbourhood safety were favourable, and the associations of physical neighbourhood environment characteristics with children's PA and ST depended on PA-related parenting practices. Community cohesion was positively related to children's PA and negatively related to ST, while parental promotion of ST was positively associated with children's ST. Correlates of children's PA and ST did not differ by city.

CONCLUSIONS

The substantial differences in activity patterns between Hong Kong Chinese and US Latino preschool-aged children observed in this study are likely due to a combination of cultural and built environmental factors. However, the fact that no between-city differences in correlates of PA and ST were detected indicates that both populations of children are equally affected by parent-perceived neighbourhood environmental characteristics and parenting practices. Overall, this study highlights the importance of considering how various individual-, home- and neighbourhood physical and social factors interact to influence young children's health-promoting activity levels.

The Influence of the Early Childhood Education and Care Environment on Young Children's Physical Activity: Development and Reliability of the PLAYCE Study Environmental Audit and Educator Survey

(1) Background: Participation in physical activity is crucial for the healthy growth and development of young children. More robust measurement of environmental influences on children’s physical activity in early childhood education and care (ECEC) settings may help resolve inconsistencies in the literature. This study evaluated the reliability of an environmental audit and educator practice survey for assessing ECEC physical, policy, and social environments related to young children’s physical activity. (2) Methods: A convenience sample of 20 ECEC centres participated in this PLAYCE (Play Spaces and Environments for Children’s Physical Activity) sub-study. Trained auditors conducted audits and educators completed surveys, two weeks apart. Test-retest reliability of the survey (n = 32), inter-rater (n = 20 pairs) and intra-rater reliability (n = 38) of the audit was assessed using intra-class correlation coefficients (ICCs), Kappa statistics and percent agreement. (3) Results: Intra-rater and inter-rater reliability ICCs for outdoor equipment, spaces and features were good to excellent (ICC = 0.70–0.94), while ratings for indoor equipment, media and spaces varied from fair to excellent (ICC = 0.46–0.78). The majority of items were rated by Kappa as moderate or above for intra-rater, inter-rater and survey test-retest reliability. (4) Conclusions: The PLAYCE Study instruments provide reliable measures of ECEC physical activity environments which can help to better understand influences on young children’s physical activity.

Physical Activity and Fundamental Movement Skills of 3- to 5-Year-Old Children in Irish Preschool Services

The aim of this study was to quantify levels of physical activity (PA) and fundamental movement skills (FMS) of children aged 3 to 5 years in Irish preschool services during care hours, and investigate the relationship between these two variables. Data were collected from 141 children (50.3% boys, ageM = 3.9 ± 0.5 years) across 9 preschool services. Measurements included PA via accelerometry, and proficiency in four FMS (run, vertical jump, throw and catch). The recommended guideline of 15 minutes of PA per hour (min PA/hour) was met by 35% of children (M = 13.6 min PA/hour). Significant differences in mean PA per hour were found by gender, with boys (14.2 min PA/hour) more active than girls (13.0 min PA/ hour), and age, with younger children (14.2 min PA/hour) more active than older (12.6 minutes PA/hour). Percentage of children proficient in the run was high (88.4%), but low across the other skills (4.9%–18.5%). Significant differences were identified by gender for vertical jump with girls scoring higher than boys. No significant relationship was found between FMS and total PA. Low levels of PA and FMS proficiency highlight need for intervention in early years settings to ensure children develop skills to participate in PA.

Current Guidelines for Obesity Prevention in Childhood and Adolescence

OBJECTIVE

Current guidelines for prevention of obesity in childhood and adolescence are discussed.

METHODS

A literature search was performed in Medline via PubMed, and appropriate studies were analyzed.

RESULTS

Programs to prevent childhood obesity have so far remained mainly school-based and effects have been limited. Analyses by age group show that prevention programs have the best results in younger children (<12 years). Evidence-based recommendations for pre-school- and early school-aged children indicate the need for interventions that address parents and teachers alike. During adolescence, school-based interventions proved most effective when adolescents were addressed directly. To date, obesity prevention programs have mainly focused on behavior-oriented prevention. Recommendations for community- or environment-based prevention have been suggested by the German Alliance of Noncommunicable Diseases and include a minimum of 1 h of physical activity at school, promotion of healthy food choices by taxing unhealthy foods, mandatory standards for meals at kindergartens and schools as well as a ban on unhealthy food advertisement aimed at children.

CONCLUSION

Behavior-oriented prevention programs showed only limited long-term effects. Certain groups at risk for the development of obesity are not reached effectively by current programs. Although universally valid conclusions cannot be drawn given the heterogeneity of available studies, clearly combining behavior-based programs with community-based prevention to counteract an 'obesogenic environment' is crucial for sustainable success of future obesity prevention programs.

The Preschool Activity, Technology, Health, Adiposity, Behaviour and Cognition (PATH-ABC) cohort study: rationale and design

BACKGROUND

Prevalence estimates internationally suggest that many preschool-aged children (3-5 years) are insufficiently physically active and engage in high levels of screen-based entertainment. Early childhood is the developmental period for which we know the least about the effects of physical activity on development and health. Likewise, rapid technological advancements in mobile electronic media have made screen-based forms of entertainment for young children ubiquitous, and research demonstrating the impacts on cognition, psychosocial well-being, and health has lagged behind the rate of adoption of these technologies. The purpose of the Preschool Activity, Technology, Health, Adiposity, Behaviour and Cognition (PATH-ABC) study is to investigate if physical activity and screen-based entertainment are independently associated with cognitive and psychosocial development, and health outcomes in young children, and if so, how much and which types of these behaviours might be most influential.

METHODS

The PATH-ABC study is a prospective cohort, aiming to recruit 430 3-5 year-old children. Children are recruited through and complete initial assessments at their Early Childhood Education and Care (ECEC) centre, and then 12-months later at their centre or school. Direct assessments are made of children's habitual physical activity using accelerometry, cognitive (executive function) and language development (expressive vocabulary), psychosocial development (emotional understanding, Theory of Mind, empathy, and heart rate variability), adiposity (body mass index and waist circumference), and cardiovascular health (blood pressure and retinal micro- vasculature). Educators report on children's psychological strengths and difficulties and self-regulation. Parents report on children's habitual use of electronic media and other child, parent and household characteristics.

DISCUSSION

The PATH-ABC study aims to provide evidence to enhance understanding of how much and which types of physical activity and screen-based media influence development and health in preschool-aged children. This information would benefit parents, educators, health professionals and governments seeking to develop strategies and policies to give young children the best start in life by promoting healthy levels of physical activity and electronic media use.

Influence of the day care, home and neighbourhood environment on young children's physical activity and health: protocol for the PLAYCE observational study

INTRODUCTION

The early years are a critical period in a child's health and development, yet most preschool children fail to meet physical activity guidelines. Outside of the home and neighbourhood, children spend a large proportion of time within early childhood education and care (ECEC) services such as long day care. Research is required to determine how the design of day care outdoor (and indoor) spaces provides opportunities or constraints for physical activity. A significant evidence gap surrounds what objectively measured attributes of the home and neighbourhood environment influence preschoolers' physical activity. The PLAY Spaces & Environments for Children's Physical Activity (PLAYCE) study will empirically investigate the relative and cumulative influence of the day care, home and neighbourhood environment on preschoolers' physical activity.

METHODS AND ANALYSIS

The PLAYCE study is a cross-sectional observational study (April 2015 to April 2018) of 2400 children aged 2-5 years attending long day care in metropolitan Perth, Western Australia. Accelerometers will measure physical activity with indoor physical activity measured using radio frequency identification. Global positioning systems will be used to determine outdoor location of physical activity around the home and neighbourhood for a subsample (n=310). The day care environment will be objectively measured using a validated audit tool. Other potential individual, social and physical environmental influences on preschoolers' physical activity will be collected by geographic information systems measures, parent and day care educator surveys.

ETHICS AND DISSEMINATION

Ethical approval has been granted by The University of Western Australia Human Ethics Research Committee, approval number RA/4/1/7417. Findings will be published in international peer-reviewed journals and presented at international conferences. Key findings will be disseminated to stakeholders, collaborators, policymakers and practitioners working in the ECEC sector. Day care centre directors and parents will be given a summary report of the key findings.

Increasing physical activity among young children from disadvantaged communities: study protocol of a group randomised controlled effectiveness trial

BACKGROUND

Participation in regular physical activity (PA) during the early years helps children achieve healthy body weight and can substantially improve motor development, bone health, psychosocial health and cognitive development. Despite common assumptions that young children are naturally active, evidence shows that they are insufficiently active for health and developmental benefits. Exploring strategies to increase physical activity in young children is a public health and research priority.

METHODS

Jump Start is a multi-component, multi-setting PA and gross motor skill intervention for young children aged 3-5 years in disadvantaged areas of New South Wales, Australia. The intervention will be evaluated using a two-arm, parallel group, randomised cluster trial. The Jump Start protocol was based on Social Cognitive Theory and includes five components: a structured gross motor skill lesson (Jump In); unstructured outdoor PA and gross motor skill time (Jump Out); energy breaks (Jump Up); activities connecting movement to learning experiences (Jump Through); and a home-based family component to promote PA and gross motor skill (Jump Home). Early childhood education and care centres will be demographically matched and randomised to Jump Start (intervention) or usual practice (comparison) group. The intervention group receive Jump Start professional development, program resources, monthly newsletters and ongoing intervention support. Outcomes include change in total PA (accelerometers) within centre hours, gross motor skill development (Test of Gross Motor Development-2), weight status (body mass index), bone strength (Sunlight MiniOmni Ultrasound Bone Sonometer), self-regulation (Heads-Toes-Knees-Shoulders, executive function tasks, and proxy-report Temperament and Approaches to learning scales), and educator and parent self-efficacy. Extensive quantitative and qualitative process evaluation and a cost-effectiveness evaluation will be conducted.

DISCUSSION

The Jump Start intervention is a unique program to address low levels of PA and gross motor skill proficiency, and support healthy lifestyle behaviours among young children in disadvantaged communities. If shown to be efficacious, the Jump Start approach can be expected to have implications for early childhood education and care policies and practices, and ultimately a positive effect on the health and development across the life course.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry No: ACTRN12614000597695 , first received: June 5, 2014.

Effectiveness of the IDEFICS intervention on objectively measured physical activity and sedentary time in European children

BACKGROUND

This paper reports on the effectiveness of the prevention of dietary- and lifestyle-induced health effects in children and infants (IDEFICS) intervention on objectively measured physical activity (PA) and sedentary time (ST) in 2- to 9.9-year-old European boys and girls.

METHODS

The intervention was evaluated after 2 years through a non-randomized cluster-controlled trial in eight European countries (one control and one intervention community per country). All children in the intervention group received a culturally adapted childhood obesity prevention programme through the community, schools/kindergartens and family. A random sub-sample of children participating in the IDEFICS study wore an accelerometer at baseline and follow-up for at least 3 days (n = 9,184). Of this sample, 81% provided valid accelerometer data at baseline (n = 7,413; 51% boys; 6.21 ± 1.76 years; boys: 617 ± 170 cpm day(-1) ; girls 556 ± 156 cpm day(-1) ) and 3,010 children provided valid accelerometer data at baseline and during the follow-up survey 2 years later.

RESULTS

In boys and girls, no significant differences in PA and ST were found between intervention and control groups over 2 years. Strong temporal effects were found in the total sample of boys and girls: the percentage of time spent in light PA per day decreased by 4 percentage points in both boys and girls between baseline and follow-up (both: p < 0.001), while time spent in ST per day increased by 4 percentage points in both sexes over time (both: p < 0.001). Percentage of time spent in moderate-to-vigorous PA per day remained stable over time in boys and girls.

CONCLUSION

Despite the socio-ecological approach and implementation of a culturally adapted intervention in each country, no effects of the IDEFICS intervention were found on children's objectively measured PA and ST. Behavioural interventions for children may need to enhance specificity and intensity at the family level using other behaviour change techniques and more direct strategies to reach parents.

Child physical activity levels and associations with modifiable characteristics in centre-based childcare

OBJECTIVE

To describe children's physical activity levels during childcare and associations with modifiable characteristics.

METHODS

A cross-sectional study of 328 preschool children (43% girls; age 3-5 years) and 145 staff from 20 long day care centres in the Hunter Region of NSW, Australia. Pedometers assessed child physical activity levels. Centre characteristics and staff attitudes and behaviours towards children's physical activity were assessed using surveys, interviews and observational audit. Results were analysed using descriptive statistics and linear regression.

RESULTS

Over the measurement period, average step count of children was 15.8 (SD=6.8) steps/minute. Four-year-olds had the highest step counts (16.4, SD=7.1, p=0.03) with no differences by sex. Step counts were significantly higher in centres that had a written physical activity policy (+3.8 steps/minute, p=0.03) and where staff led structured physical activity (+3.7 steps/minute, p<0.001) and joined in active play (+2.9 steps/minute, p=0.06).

CONCLUSIONS

Written physical activity policy, structured staff-led physical activity and staff joining in active play were associated with higher levels of physical activity.

IMPLICATIONS

Childcare physical activity interventions should consider including strategies to encourage written physical activity policies and support structured staff led physical activities.

An intervention for improving the lifestyle habits of kindergarten children in Israel: a cluster-randomised controlled trial investigation

OBJECTIVE

To assess the effectiveness of an intervention programme to improve kindergarten children's eating and leisure habits in Israel.

DESIGN

A cluster-randomised controlled trial.

SETTING

Six full-day kindergartens in Israel were randomly divided into three groups. Group A received the full intervention programme, which included lessons on good eating habits and daily physical exercise. Group B received a partial intervention of lessons only. Group C, the reference group, did not receive any intervention.

SUBJECTS

Children aged 4-6 years (n 204) were recruited for the study.

METHODS

Objective data for weight and height were collected to calculate BMI Z-scores. Activity, sedentary time, sleeping hours and daily energy intake were assessed via a parental questionnaire. Nutritional knowledge was assessed by a single dietitian using a questionnaire addressed to the children. Assessments were done at baseline and at the end of the intervention.

RESULTS

After adjustment for baseline levels we observed a significant reduction in daily energy intake for the full intervention group A (P = 0.03). A positive intervention effect was demonstrated on nutritional knowledge in the partial intervention group B (P = 0.03), although no significant change was demonstrated for BMI Z-score.

CONCLUSIONS

The study supports the incorporation of education on healthy lifestyle habits and physical activity into the curricula of kindergartens.

A socio-ecological approach to physical activity interventions in childcare: a systematic review

The promotion of physical activity (PA) in young children requires effective interventions. This article reviews the evidence on PA interventions in childcare by applying a socio-ecological approach. A computer-based literature search for intervention studies aimed at increasing children's PA levels was run across four databases: SPORTDiscus, ISI Web of Science, PsycINFO and ERIC. The participants had to be in childcare, aged 2-6-year-old, and their pre- and post- intervention PA levels measured. Selection was restricted to peer-reviewed publications and to studies conducted in childcare settings. Twenty-three studies met the inclusion criteria and their methodological quality was assessed. Seven studies exhibited high methodological quality; twelve were rated as moderate and four low. The effectiveness of the interventions was determined according to the post-intervention behavioral changes reported in children's PA. Fourteen studies found increases in PA levels or reductions in sedentary time, although the changes were modest. The data remain too limited to allow firm conclusions to be drawn on the effectiveness of the components mediating PA interventions, although PA-specific in-service teacher training seems a potential strategy. The findings of this review indicate that children's PA remained low and did not approach the 180 min/day criteria. It may be that more intensive multilevel and multicomponent interventions based on a comprehensive model are needed.

Changes in physical activity over time in young children: a longitudinal study using accelerometers

Previous research has suggested that marked declines in physical activity occur during the preschool years, and across the transition into school. However, longitudinal studies using objective measures of activity have been limited by sample size and length of follow-up. The aims of this study were to determine how overall activity and time in different intensities of activity change in children followed from 3 to 7 years. Children (n = 242) wore Actical accelerometers at 3, 4, 5, 5.5, 6.5 and 7 years of age during all waking and sleeping hours for a minimum of 5 days. Time in sedentary (S), light (L), moderate (M), and vigorous (V) physical activity was determined using available cut points. Data were analyzed using a mixed model and expressed as counts per minute (cpm, overall activity) and the ratio of active time to sedentary time (LMV:S), adjusted for multiple confounders including sex, age, time worn, and weather. At 5 years, physical activity had declined substantially to around half that observed at 3 years. Although starting school was associated with a further short-term (6-month) decline in activity (cpm) in both boys (difference; 95% CI: -98; -149, -46) and girls (-124; -174, -74, both P<0.001), this proved to be relatively transient; activity levels were similar at 6-7 years as they were just prior to starting school. Boys were more physically active than girls as indicated by an overall 12% (95% CI: 2, 22%) higher ratio of active to sedentary time (P = 0.014), but the pattern of this difference did not change from 3 to 7 years. Time worn and weather variables were significant predictors of activity. In conclusion, both boys and girls show a marked decline in activity from 3 to 4 years of age, a decrease that is essentially maintained through to 7 years of age. Factors driving this marked decrease need to be determined to enable the development of targeted interventions.