Dylan P Cliff

• BEd, PhD
• Professor (Associate) at University of Wollongong

Objective: To investigate associations of traditional (program viewing) and contemporary (electronic applications, or apps) electronic media use with preschoolers' executive function and psychosocial development 12 months later. Methods: We conducted an analysis of longitudinal data from 185 children (mean age, 4.2 ± 0.6 years). Parents reported...

Objective: To investigate: i) prospective associations between media exposure (television viewing, computers, and electronic games) at 2 years and self-regulation at 4 and 6 years, and ii) bi-directional associations between media exposure and self-regulation at 4 and 6 years. We hypothesized that media exposure and self-regulation would display a...

Background: The new Australian 24-Hour Movement Guidelines for the Early Years recommend that, for preschoolers, a healthy 24-h includes: i) ≥180 min of physical activity, including ≥60 min of energetic play, ii) ≤1 h of sedentary screen time, and iii) 10-13 h of good quality sleep. Using an Australian sample, this study reports the proportion of...

Background: In 2017, the Australian Government funded the update of the National Physical Activity Recommendations for Children 0-5 years, with the intention that they be an integration of movement behaviours across the 24-h period. The benefit for Australia was that it could leverage research in Canada in the development of their 24-h guidelines...

Purpose To investigate the associations of physical activity intensity and modified organized sport with cognitive (i.e., executive functions) and psychosocial development in preschoolers. Methods Preschool children (n = 247; 4.2 ± 0.6 years) had their physical activity intensity (light: LPA; moderate: MPA; vigorous: VPA; moderate-to-vigorous: MVP...

Background While there is growing evidence on 24-hour movement behaviours (physical activity, sedentary behaviour, and sleep) in non-displacement settings, understanding these behaviours among displaced children remains limited. This scoping review explored evidence on 24-hour movement behaviours, including active play and health among forcibly dis...

Background Screen-based devices have become a pervasive feature in the lives of young children. Understanding the ecological influences determining young children’s screen use is imperative for promoting healthy screen habits. While individual studies have examined various factors influencing children’s screen use across the early years, few studie...

Background Encouraging healthy eating and physical activity in children has long-term benefits for their health and development, however many do not meet the requirements for fruit and vegetable consumption, or physical activity. Experiential learning (EL) has been shown to improve children’s healthy eating and physical activity-related knowledge,...

Background There are no reviews describing current measurement protocols and accelerometer processing decisions that are being used in 24-h MovBeh studies, across the lifespan. We aim to synthesise information on methods for assessing 24-h movement behaviors using accelerometry across all age groups. Main Body PubMed, PsycINFO, SPORTDiscus, and EM...

Background : Understanding the factors influencing 24-hour movement behaviors is important for designing appropriate health promotion strategies. We examined the multidimensional correlates of physical activity, sedentary behavior, screen time, and sleep among children under 5 years of age in Ethiopia. Methods : Cross-sectional study conducted in A...

Background Recent research suggests that children spend increasing amounts of time engaging in screen-based activities and less time outdoors in natural environments. There is a growing body of theory-driven literature evidencing that child screen use and exposure to nature are associated with wellbeing outcomes in contrasting ways. However, few st...

Background Sleep, sedentary behaviour, physical activity, and the composition of these movement behaviours across the 24-h day are associated with cognitive function in early years children. This study used a Goldilocks day compositional data analysis approach to identify the optimal duration of sleep, sedentary behaviour, light physical activity,...

Background Sleep, sedentary behaviour, and physical activity are essential components within the 24-hour time frame. Existing questionnaires used to measure these behaviours have insufficient measurement properties and are unsuitable for assessing compliance with the WHO Physical Activity and 24-hour Movement Guidelines. To describe the development...

Importance The prevalence estimates of physical activity, sedentary behavior, and sleep (collectively known as movement behaviors) in 3- and 4-year-old children worldwide remains uncertain. Objective To report the proportion of 3- and 4-year-old children who met the World Health Organization guidelines for physical activity, sedentary behavior, an...

Background Canada, Australia, the World Health Organization and other countries have released 24-hour movement guidelines for the early years which integrate physical activity, sedentary behaviour, and sleep, focusing on supporting children to achieve a healthy 24-hour day. The guideline evidence synthesis, however, highlighted the dearth of high-q...

Background The World Health Organisation (WHO) has called for more evidence on 24-hour movement behaviours from low- and middle-income countries. We examined the proportion of Ethiopian children aged 3.0-4.9 years who met the WHO guidelines on physical activity, screen time and sleep for children under the age of five, and the associations between...

Background Children’s physical activity and screen time behaviours impact their physical health and well-being. In Australia, less than half of children meet daily physical activity recommendations and only one-third meet daily screen time recommendations. Nearly half a million Australian school children aged 5-12 attend Outside School Hours Care (...

Importance The multifaceted nature of screen use has been largely overlooked in favor of a simplistic unidimensional measure of overall screen time when evaluating the benefits and risks of screen use to early childhood development. Objective To conduct a systematic review and meta-analysis to examine associations of screen use contexts in early c...

Background The World Health Organisation (WHO) has called for more evidence on 24-hour movement behaviours from low- and middle-income countries. We examined the proportion of Ethiopian children aged 3.0-4.9 years who met the WHO guidelines on physical activity, sedentary behaviour and sleep for children under the age of five, and the associations...

Background This systematic review examined the effectiveness of experiential learning interventions for improving children’s physical activity knowledge, attitudes, and behaviours. It also aimed to identify intervention characteristics that resulted in the greatest impact. Methods Four databases: Education Research Complete, Scopus, Web of Science...

Physical activity (PA) participation is prone to decline during childhood and adolescence. In Australia, this decline has been shown to particularly occur in active play. This study aimed to identify sociodemographic moderators of change in active play between 10-11y and 12-13y among Australian youth. The data were sourced from Waves 6–7 of the Lon...

Background: Health benefits have been linked with physical activity (PA), as well as some domains of PA among youth (e.g. organized PA and active transport). However, less is known about whether some PA domains are more beneficial than others. There is also a lack of evidence about whether health outcomes are related to the composition of PA (i.e....

Background: We aim to systematically review the literature on measurement properties of self- and proxy-reported questionnaires measuring 24-hour movement behaviors in children and adolescents. Methods: PubMed, PsycINFO, SPORTDiscus, and EMBASE were searched until June 2021. Studies were included if the sample size for validity studies had 50 pa...

Background Evidence for longitudinal associations between childhood weight status and academic achievement remains unclear due to considerable heterogeneity in study design, measures of academic achievement and appropriate categorization of weight status. Objective To examine longitudinal associations between childhood weight status (underweight,...

Abstract Background Physical activity (PA) participation among youth tends to be insufficient and is prone to decline with age. In Australia, this decline has been shown to particularly occur in the domain of non-organized PA (e.g. active play and informal sport) between childhood and adolescence. However, information about changes in more specific...

Background: Little is known about the influence of 24-hour movement behaviors on children's psychosocial health when transitioning from primary to secondary school. This study described changes in 24-hour domain-specific movement behavior composition and explored their associations with changes in psychosocial health during this transition. Metho...

Background This study aimed to investigate prosocial behaviour—those behaviours that benefit others or enhance relationships with others—as a mediator of the associations between green space quality and child health-related outcomes (physical activity, mental health, and health-related quality of life (HRQOL)). Methods This study involved data fro...

Background Sleep, sedentary behaviour and physical activity are constituent parts of a 24h period and there are several questionnaires to measure these movement behaviours, the objective was to systematically review the literature on content and measurement properties of self- and proxy-reported questionnaires measuring movement behaviours in adult...

Background In 2018, the Australian Government updated the Australian Physical Activity and Sedentary Behaviour Guidelines for Children and Young People. A requirement of this update was the incorporation of a 24-hour approach to movement, recognising the importance of adequate sleep. The purpose of this paper was to describe how the updated Austral...

Experiential learning is the process where learners create meaning from direct experience. This systematic review aimed to examine the effects of experiential learning activities on dietary outcomes (knowledge, attitudes, behaviors) in children. Four databases: Education Research Complete, Scopus, Web of Science and PsychINFO were searched from dat...

Background Little is known about how activity patterns change throughout childhood. This study examined changes and tracking of total volume and bouts of physical activity (PA) and sedentary time (SED) from early to late childhood. Methods Volume and bouts of SED and light-, moderate- and vigorous-intensity PA (LPA, MPA and VPA) were assessed by a...

The aim of the present study was to characterize sedentary time (ST) and sedentary bouts among young children, across a typical week and by day type (childcare days, non-childcare days and weekends), over a 12-month period. ST % (ST/accelerometer wear time*100) and number of sedentary bouts/hours were assessed using accelerometers at two time-point...

Potential pathways linking green space quality to prosocial behaviour have not been investigated so far. This study aimed to examine 15 candidate mediators of the association between green space quality and prosocial behaviour across physical activity, social interaction, health-related quality of life (HRQOL), child and caregiver mental health. Th...

It remains unclear whether the time-use composition of 24-h movement behaviours (sleep, sedentary time (ST), physical activity (PA)) and recreational screen use are independently associated with psychosocial health. This study examined the cross-sectional and longitudinal associations between 24-h movement behaviour composition, recreational screen...

Importance Cardiorespiratory fitness is an important marker of childhood health and low fitness levels are a risk factor for disease later in life. Levels of children's fitness have declined in recent decades. Whether school-based physical activity interventions can increase fitness at the population level remains unclear. Objective To evaluate th...

Background: Tummy time is recommended by the World Health Organization as part of its global movement guidelines for infant physical activity. To enable objective measurement of tummy time, accelerometer wear and nonwear time requires validation. The purpose of this study was to validate GENEActiv wear and nonwear time for use in infants. Methods...

Background: This study aimed to understand whether a higher number of sedentary bouts (SED bouts) and higher levels of sedentary time (SED time) occur according to different day types (childcare days, nonchildcare weekdays, and weekends) in Australian toddlers (1-2.99 y) and preschoolers (3-5.99 y). Methods: The SED time and bouts were assessed...

Background Physical activity (PA) decreases and sedentary time (SED) increases across childhood, with both behaviours tracking. However, no studies have examined how accumulation patterns of PA and SED (i.e., prolonged bouts, frequency of breaks in sedentary time) change and track over time. The aim of this study was to investigate longitudinal cha...

This study examined concurrent changes in all components of 24-h movement behaviours (24-h MB) (sleep, sedentary behaviour [SB] and physical activity [PA]) and compliance with the Australian 24-Hour Movement Guidelines over the primary to the secondary school transition period. The analytical sample included 83 children (60.2% girls) who provided v...

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,...

Background Studies investigating the potential role of neighbourhood green space quality on the development of prosocial behaviour among children are sparse. This study aimed to investigate the longitudinal association between caregiver perceived green space quality and child prosocial behaviour, and identify potential effect modifiers of the assoc...

BACKGROUND To achieve sustainability, we must consider scalable improvements in student movement behavior in the classroom setting, educational priorities. Flexible learning spaces that employ student‐centered pedagogy and contain a range of furniture and layout options, implemented to improve educational outcomes, may enable unintended health bene...

This article presents the perceptions and experiences of 12 school principals, 35 teachers and 85 students on the influences and processes used by eight Australian government primary and secondary schools to transform traditionally arranged classrooms into flexible learning spaces. Characterised by a variety of furniture and layout options, these s...

Background: Current evidence from studies on green space and child prosocial behaviour suggests a paucity of studies investigating the plausible role of green space quality in shaping the development of prosocial behaviour. This study aimed to examine longitudinal association between green space quality and prosocial behaviour among children. Meth...

Participation in physical activity (PA) tends to decline between childhood and adolescence, and in Australia the bulk of this decline has been shown to occur in the domain of non-organised PA (e.g. active play, informal sports). A better understanding of the reasons for the decline in non-organised PA may support strategies to counter barriers and...

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 usi...

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,...

Physical activity (PA) tends to decline during late childhood and adolescence. In Australia, this decline has been shown to particularly occur non-organized PA (e.g., active play, informal sport). This study aimed to explore predictors of non-organized PA at 13y; and decline between 11y and 13y. Data were sourced from the Longitudinal Study of Aust...

Background: The impact of declining physical activity and increased sedentary behaviour in children and adolescents globally prompted the development of national and international physical activity guidelines. This research aims to systematically identify and compare national and international physical activity guidelines for children and adolesce...

An amendment to this paper has been published and can be accessed via the original article.

The plausible role of nearby green space in influencing prosocial behaviour among children and adolescents has been studied recently. However, no review has been conducted of the evidence testing the association between green space and prosocial behaviour. This systematic review addresses this gap among children and adolescents. Within this review,...

Background: Several countries have released movement guidelines for children under 5 that incorporate guidelines for sleep, physical activity and sedentary behavior. This study examines prospective associations of preschool children's compliance with the 24-Hour Australian movement guidelines (sleep, physical activity, screen time) and physiologic...

Background Young children appear to spend large portions of their waking time being sedentary. Understanding the correlates of sedentary time would assist in developing effective interventions among young children. The purpose of this systematic review was to summarise the current literature on the correlates of objectively measured sedentary time...

Background: Information about the domains of physical activity (PA) that are most prone to decline between late childhood (11 y), early adolescence (13 y), and mid-adolescence (15 y) may support more targeted health promotion strategies. This study explored longitudinal trends in nonorganized PA, organized PA, active transport and active chores/wo...

Objective To examine whether meeting the Australian 24-Hour Movement Guidelines was associated with cognitive and psychosocial development 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 accel...

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 t...

Background: Physical activity (PA) tends to decline during late childhood and adolescence. In Australia, this decline has been shown to occur particularly in non-organized PA (e.g. active play and informal sport). Using a social marketing approach, segments of youth may be identified and targeted based on their profile of alternative activities th...

Objectives: To describe how children's time spent in the 24-h movement behaviours of physical activity (PA), sedentary behaviour (SB) and sleep change, individually and collectively, across the transition from primary to secondary school. Design: Systematic review. Methods: Six electronic databases were searched from January 1990 to May 2019....

Globally, many schools are replacing traditional classrooms with innovative flexible learning spaces to improve academic outcomes. Little is known about the effect on classroom behaviour. Students from nine secondary schools (n = 60, M age = 13.2±1.0y) were observed via momentary time sampling for a 30 minute period, in both a traditionally furnish...

Purpose: To examine the acute effects of a reduced sitting day on executive function (EF) and musculoskeletal health in preschoolers. Methods: A sample of 29 children (54% boys; 4-5 y) participated in a randomized cross-over trial. Each child completed 2 protocols, which simulate a day at childcare in random order for 2.5 hours; a typical presch...

Objectives: ActiGraph accelerometer cut-points are commonly used to classify sedentary behaviour (SB) in young children. However, they vary from 5counts/5s to 301counts/15s, resulting in different estimates and inconsistent findings. The aim was to examine the concurrent validity of ActiGraph GT3X+cut-points against the activPAL for measuring SB i...

Background: Although there is increasing evidence regarding children's screen time, little is known about children's sitting. This study aimed to determine the correlates of screen time and sitting in 6- to 8-year-old children. Methods: In 2011-2012, parents in the Healthy Active Preschool and Primary Years (HAPPY) study (n = 498) reported their...

Objectives: The aim of this study was to simultaneously explore multiple pathways through which sports participation during childhood and adolescence may be associated with adiposity over time. Design: Data were drawn from the Kindergarten cohort of the Longitudinal Study of Australian Children. A total of 4286 children provided sports participa...

Background Despite growing scientific interest in the benefits of breaking up sedentary time with intermittent standing or walking, few studies have investigated the energy cost of posture transitions. This study aimed to determine whether posture transitions are associated with increased energy expenditure in preschool children. Methods Forty chi...

Objectives: Many schools internationally are replacing traditional classrooms (TC) with innovative flexible learning spaces (FLS) to improve academic outcomes. Via a stealth approach, there may be additional unintended health benefits if students reduce their total and prolonged sitting. The aim of this study was to compare student sitting pattern...

The 2017 Australian and Canadian 24-hour movement guidelines recommend infants receive 30 minutes of tummy time daily. Currently, there are no validated objective measurement tools or devices to assess tummy time. The purpose of this study was to: 1) test the practicality of using devices on infants as an objective measure of tummy time, and 2) tes...

Definitions of positions used to code video analysis. (PDF)

Practicality questionnaire. (PDF)

Algorithm for GENEActiv device to classify prone, non-prone and prone supported positions. (PDF)

Bland-Altman plots for non-prone and prone supported positions. (PDF)

Objectives: Physical activity (PA) participation is prone to decline during adolescence. An understanding of the domains of PA that are susceptible to decline may support a more targeted approach to PA and health promotion. The aim of this study was to review longitudinal trends in participation in four PA domains during childhood and adolescence:...

Background The early years have been identified as a critical period during which sedentary habits may be established, as this behaviour appears to track throughout life. Objective The purpose of this systematic review and meta‐analysis is to summarise the current literature on the prevalence of sedentary behaviour in children aged 1 to 5.99 years...

Background Overweight and obesity among young people is alarmingly high. While hundreds of millions of children participate in organised sports worldwide, it is currently unknown whether time spent in organised sports is associated with levels of adiposity among young people. This study aimed to investigate bidirectional associations between partic...

In recognition of the evolving learning needs of twenty-first century school students, changes to teaching practices and the incorporation of technology are increasingly accompanied by modifications to the built classroom environment. Typically rows of desk and chairs are replaced with a range of furniture that can be configured in various ways to...

Background: The objective of this paper is to derive a wrist-placed cut-point threshold for distinguishing sedentary behaviors from light-intensity walking using the ActiGraph GT3X+ in children. Methods: This study employed a cross-sectional study design, typically used in measurement-related studies. A sample of 167 children, ages 5–11 years (mean...

Young children spend a high proportion of their time at childcare sitting. Reducing sitting time or breaking up prolonged periods of sitting may be positively associated with health outcomes among children. The purpose of this study was to identify childcare educators’ perceptions of what environmental and policy modifications could be made within...

The aim of this study was to test the feasibility, acceptability and potential efficacy of a childcare-based intervention to reduce total and prolonged sitting time in pre-schoolers. Four centres and 115 pre-schoolers (44 % boys; 4.1y) participated in a 3-month, 2-arm pilot cluster randomised controlled trial. Feasibility and acceptability were ass...

Objectives: Adolescents spend large proportions of the school day sitting; potentially increasing their health risks. This study aimed to evaluate the feasibility, acceptability and potential efficacy of a school-based intervention to reduce adolescent sitting time during the school day. Design: Two-arm parallel-group randomised controlled trial...

The ability to compare published group-level estimates of objectively measured moderate-to-vigorous physical activity (MVPA) across studies continues to increase in difficulty. The objective of this study was to develop conversion equations and demonstrate their utility to compare estimates of MVPA derived from the wrist and hip. Three studies of y...

Early self-regulation is essential to positive life outcomes and sports are speculated to generate self-regulatory improvements. Preliminary research supports this assertion, showing some sports might yield short-term self-regulatory improvements and elite athletes tend to excel in cognitive functions underlying self-regulation. What remains unclea...

Background: For effective public health and surveillance it is important to document the proportion of young children who meet the new Australian Integrated 24 h Movement Guidelines for the Early Years and how these associate with health outcomes. We aimed to (i) assess compliance with the new Integrated 24 h Movement Guidelines for the Early Year...

Objective Quality physical education (PE) is the cornerstone of comprehensive school physical activity (PA) promotion programmes. We tested the efficacy of a teacher professional learning intervention, delivered partially via the internet, designed to maximise opportunities for students to be active during PE lessons and enhance adolescents’ motiva...