Simone Johanna Josefa Maria Verswijveren

Objectives: To describe device-measured movement behaviours in a large sample of middle-aged and older Australian adults using complementary posture- and intensity-based accelerometers, examine variation across demographic groups, and identify behavioural phenotypes using clustering approaches Design: Cross-sectional analysis of the Australian Breakthrough Cancer (ABC) Study Accelerometer Sub-study (ACM). Methods: Participants from the ABC cohort completed seven days of simultaneous monitoring using a thigh-mounted activPAL and waist-mounted ActiGraph GT3X+. activPAL characterised posture-based behaviours (sitting, lying, standing, stepping, postural transitions, and sedentary accumulation), while ActiGraph characterised intensity-based activity (sedentary, light, and moderate-to-vigorous physical activity [MVPA]). Movement behaviours were summarised overall and by gender, age group, body mass index (BMI), and education. Behavioural phenotypes were identified using k-means clustering. Results: Among 4,238 ACM participants, 3,426 met inclusion criteria with valid data from both devices (1,711 females; 1,715 males). Participants accumulated substantially more time in sedentary and low-intensity behaviours than in MVPA. activPAL estimates indicated mean daily time of 379.3 min sitting, 282.2 min lying, 160.8 min standing, and 64.5 min stepping, with a mean of 5,185 steps/day. ActiGraph estimates indicated 584.0 min/day sedentary time, 290.9 min/day light-intensity activity, and 33.2 min/day MVPA. Considerable heterogeneity in movement behaviours was observed between individuals, whereas demographic differences were comparatively modest. Three behavioural phenotypes were identified: active/fragmented (24%), low activity (41%), and prolonged sedentary (35%). Notably, the low-activity and prolonged sedentary phenotypes were distinct, indicating that low overall movement and prolonged uninterrupted sitting represented different behavioural patterns. The prolonged sedentary phenotype was characterised by greater uninterrupted sitting time, lower stepping time, fewer steps, lower MVPA, and fewer sit-to-stand transitions. Conclusions: Movement behaviours in middle-aged to older Australian adults (40-74 yrs) were characterised by high sedentary time, low accumulation of MVPA, and substantial between-person heterogeneity. Distinct behavioural phenotypes highlighted differences in both movement volume and sedentary accumulation patterns, suggesting that movement behaviour is multidimensional and not adequately described by single summary measures alone. These findings may help inform our understanding of population movement patterns relevant to cancer and cardiometabolic disease prevention. Key words: Accelerometry, Motor Activity, Sedentary Behaviors, Cluster Analysis, Postural Allocation, Behavioural Phenotypes

As outlined in previous chapters, the prevalence of meeting all movement behaviour guidelines in the early years is low (see Chapter 2), and there are significant short- and long-term health implications associated with this (see Chapters 5 and 6). Intervening during the early years is an attractive proposition. This is a period of rapid development, when children are establishing their behavioural preferences and habits, and a period when children's independence is limited, providing an opportune time for positive influence and the potential to concurrently target parents and children to improve health for the whole family. The opportunity to optimise 24-hour movement behaviours is further enhanced by the fact that many of the determinants of individual movement behaviours are consistent (see Chapter 3), and the interplay between the behaviours means that a single strategy has the potential to positively impact all of the individual behaviours concurrently, as well as the overall composition of movement behaviours. Many interventions targeting one or more movement behaviours also target other health behaviours and outcomes, most often diet (Jiang et al., 2024). While some of these multi-behavioural interventions are included in this chapter, the focus is on the movement behaviour components.

Objectives: To identify profiles of compositional movement behaviour patterns among children and examine cross-sectional and 12-month associations with adiposity markers and health-related quality of life (HRQoL). Design: Secondary analysis of data from the TransformUs cluster randomised controlled trial with cross-sectional and 12-month follow-up analyses. Setting: Primary schools in metropolitan and regional areas of Victoria, Australia. Participants: Children aged 7–11 years with valid accelerometer at baseline, regardless of demographic, adiposity and HRQoL data available (n=792), were included in the analytical sample for the latent profile analysis. Measures: Sedentary time, light-intensity physical activity (LPA) and moderate- to vigorous-intensity physical activity (MVPA) along with their respective mean bout lengths were derived from raw acceleration data. Latent profile analysis used these measures (total times, as isometric log ratios and mean bout lengths) as input variables to classify distinct profiles for us as a categorical exposure variable in regression models. Primary outcomes were age- and sex-standardised body mass index, waist circumference and parent-reported HRQoL at baseline. Secondary outcomes were the same measures assessed at 12-month follow-up. Results: Four distinct profiles were identified. The high MVPA-short sedentary bout profile (n=184) was characterised by the highest levels of MVPA, moderate sedentary time and the shortest mean sedentary bout duration. The low sedentary-high LPA profile (n=54) had the lowest sedentary time, the highest LPA and the longest mean LPA bout duration. Two profiles were characterised by high sedentary time: the high sedentary-long sedentary bout profile (n=149), which had the longest mean sedentary bout durations, and the high sedentary-shorter bouts profile (n=405), which also had high sedentary time but shorter bout durations for all intensities. While the omnibus Wald test for differences across profiles indicated uncertainty in the overall profile effect, the high MVPA-short sedentary bout profile had favourable adiposity levels cross-sectionally compared with the high sedentary-long sedentary bout reference profile in pairwise comparisons. No longitudinal associations were detected. Conclusions: Four distinct movement profiles were identified. Few pairwise differences between health outcomes were observed. While MVPA remains a key factor for promoting healthy body weight, our findings suggest that a variety of movement patterns - including those characterised by lower sedentary time and higher LPA - may also support health in children. Trial registration: This study is a secondary analysis of the TransformUs effectiveness-implementation trial, registered with the Australian Clinical Trials Registry (ACTRN12617000204347; 1 April 2017).

Evidence on the associations between device-measured sitting and health outcomes in children and adolescents is inconclusive; however, understanding this relationship is important given the high prevalence of sitting during these life stages and its potential implications for long-term health. This study examined associations between compositions of sitting, standing, and stepping time with adiposity markers - waist circumference (WC) and body mass index (BMI) - in 2-18-year-olds. Data were pooled from eight Australian studies (2009-2014), including 1992 participants aged 2-18 years. Postural behaviours were measured using activPAL monitors and analysed using compositional data analysis. Linear regression models, adjusted for study and wear time, were conducted (n = 1,120 for zBMI; n = 1,071 for zWC), stratified by school setting (preschool, primary, secondary). Postural compositions were significantly associated with zBMI and zWC in primary and secondary school-aged children, but not in preschoolers. In primary school children, more sitting time was associated with lower zWC. Among adolescents, more sitting was linked to higher zBMI, more standing with lower zBMI and zWC, and more stepping with higher zWC. Findings in older children and adolescents suggest that the impact of postural behaviours on adiposity may become more pronounced with age. Longitudinal studies are needed to clarify these relationships.

Background: Wearable video cameras may offer a feasible approach to assess the contexts of screen use (eg, screen content and co-use) among preschool-aged children. Objective: The objective of this study was to assess the contexts of screen use among preschool-aged children using wearable video cameras. Methods: Children aged 2 to 5 years from Melbourne, Australia, wore a video camera for 1 day in the home environment during May 2023. One researcher manually coded video footage second by second; 15% was double coded for reliability. Coding included device type, screen activity, screen content classified using Common Sense Media ratings, streaming service, setting, social interaction, screen multitasking, and concurrent behaviors. Results: A total of 37,944 seconds (10.5 hours) of video camera footage from 8 children were identified and coded as screen use, equating to 21.8% (37,944/174,290) of total camera wear time (range 0.3%-74.0%). Screen use was predominately characterized by program viewing (n=37,461, 98.7% seconds) on televisions (n=34,192, 90.1% seconds) in the lounge room (n=33,710, 88.8% seconds). Programs scored low for educational value (mean 1.7, SD 1.4 of 5 stars), and approximately one-third (3/9, 33.3%) of programs were classified as appropriate for an age older than that of the children in this sample. Screen multitasking was rare (n=46, 0.1% of seconds), and coviewing occurred in approximately one-third of all screen use (n=11,010, 29%). Conclusions: Contexts considered beneficial for development (eg, educational and age-appropriate content) were infrequently observed. This suggests that interventions to equip parents with practical strategies to identify genuine educational content and recognize and avoid age-inappropriate content are warranted. However, our small sample size limits generalizability.

Introduction: Early childhood physical activity and sedentary behavior influence long-term health, yet evidence on interventions targeting how these behaviors are accumulated – rather than just total time – is limited. This study examined the impact of a parent-focused early childhood obesity prevention intervention on preschoolers’ physical activity and sedentary behavior patterns. Methods: This study is a secondary analysis of data from the Melbourne Infant Feeding, Activity and Nutrition Trial [InFANT] clustered randomized control trial (2008–2013). Physical activity and sedentary behavior data were gathered using ActiGraph™ GT1M accelerometers. To capture insights beyond total time and examine accumulation patterns, the duration and frequency of sedentary bouts [≤100 counts per minute (cpm)], light-intensity physical activity (101–1,680 cpm) bouts, and moderate- to vigorous-intensity physical activity (≥1,681 cpm) bouts, each lasting ≥1 min, as well as the total number of sedentary breaks, were calculated at each time point. The ≥1 min cut-offs for bout durations were defined based on the medians observed in this sample (0.50 min for sedentary, 0.47 min for light-, 0.25 min for moderate- to vigorous-intensity physical activity). Multilevel regression analyses were fitted to examine intervention effects at 19 months (T3), and 3.5 (T4) and 5 (T5) years of age. Results: In total, 296, 144 and 140 participants had valid accelerometry data and were included in the analytical sample at T3, T4 and T5, respectively. The intervention had a significant and beneficial effect on the total amount of sedentary breaks at 3.5 ( β [95%CI] = 10.9[2.98,18.91) and 5 years ( β [95%CI] = 7.94[0.03,15.86). The intervention effects on all other outcomes were small and not significant. Discussion: Whilst only effects on sedentary breaks were observed, this study suggests that interventions may impact accumulation patterns in children under five. Trial registration: The Melbourne Infant Feeding, Activity and Nutrition Trial was registered with the International Standard Randomized Controlled Trial Number Register (ISRCTN81847050; 7/11/2007).

Background : Girls are less physically active than boys, and school-based physical activity interventions in co-educational settings are often less effective for girls. To help improve the design of these interventions, this study explored which school-based strategies stakeholders consider most important for increasing girls’ physical activity. Methods : A Delphi study was conducted using 3 rounds of online surveys with stakeholders from 3 groups: academics, school educators, and government representatives. In the first round, participants identified strategies they believed could increase girls’ physical activity in schools, and responses were analyzed using thematic analysis to generate a list of strategies. In the second and third rounds, participants rated the importance of these strategies using an 8-point Likert scale; consensus was defined as responses falling within a consecutive 3-point range. Results : Stakeholders across the 3 groups reached consensus on 19 strategies that emphasized creating inclusive, enjoyable, and empowering environments for girls including approaches, such as supportive school cultures, positive role modeling, safe and welcoming spaces, and opportunities for student voice. Additional areas of agreement differed slightly across groups, with academic and government representatives highlighting system-level and curriculum-related approaches, and school educators and government representatives emphasizing relational practices and operational supports, such as staff well-being and resourcing. Conclusions : Overall, the findings highlight the importance of coordinated, multilevel strategies that combine inclusive teaching practices with broader school and policy support to enhance girls’ participation in physical activity, offering guidance for researchers, educators, and policymakers seeking to design and sustain more effective school-based interventions.

Background: TransformEd is an evidence-based program that targets initial teacher education to equip future teachers with innovative strategies that increase the health, wellbeing and education outcomes of school children. Feasibility, effectiveness and implementation research demonstrate that TransformEd significantly enhances pre-service teachers’ confidence and competence to deliver such strategies. However, to date, the program has only been tested in undergraduate teaching degrees. It is important to gather more evidence for the feasibility and efficacy of the program at all levels of initial teacher education, including at postgraduate level. Methods: A feasibility study was conducted to examine the feasibility of embedding TransformEd in a Master of Teaching degree at one Australian university. Preliminary efficacy was measured by pre- and post-program surveys completed by Master of Teaching pre-service teachers who received the 12-week TransformEd program. Implementation was measured by adherence checklists completed by lecturers who delivered TransformEd. Post-program focus groups and interviews with senior academics and lecturers, respectively, explored perceptions of all eight domains of feasibility. Results: Survey results demonstrated that the TransformEd program was positively received by pre-service teachers (n = 21), resulting in improvements in several measures of teaching confidence and competence regarding delivering strategies to improve school children’s health, wellbeing and learning. The TransformEd strategies were well adopted by lecturers and implementation increased over time. Both lecturers (n = 3) and senior academics (n = 2) had positive perceptions of the program, highlighting its feasibility in postgraduate initial teacher education. Conclusion: This study supports the feasibility and preliminary efficacy of the TransformEd program in postgraduate initial teacher education and provides a foundation for a future controlled trial to rigorously evaluate its impact, with potential population-level benefits for children's health, wellbeing, and educational outcomes in Australia.

Adhering to 24-h movement guidelines protects children’s health and wellbeing. We investigated adherence among a sample of children in regional and rural Victoria, Australia. Analysis was conducted using baseline data from RESPOND, a large community-based obesity prevention intervention conducted in regional and rural Victoria, Australia. Children (aged approx. 9–12 years) self-reported screen time and wore a wrist-worn accelerometer for seven days to determine the mean daily time spent on moderate to vigorous physical activity (MVPA), light physical activity (LPA), sedentary and sleeping. Multi-level linear and logistic regressions were used to estimate associations between accelerometry outcomes and individual and school level demographics overall and by gender, accounting for school level clustering. Valid accelerometry data were obtained for 1,264 students. Twenty-two percent (22%) of boys and 16% of girls met all three movement guidelines and 11% boys and 9% of girls met none of the guidelines. Boys engaged in more MVPA, and less LPA than girls. Compared to those in grade 4 (aged approx. 9–10 years), students in grade 6 (aged approx. 11–12 years) had significantly reduced MVPA minutes (− 7.8; 95%CI –12.3, − 3.4); increased sedentary minutes (31.0; 95%CI 22.7, 39.3), and reduced odds of meeting screen time guidelines (odds ratio, 0.65; 95%CI 0.50, 0.84). Stratification by gender found these results to be consistent for boys and girls. Living in a medium or large rural town was associated with having 6.4 (95%CI 0.0, 12, 8) more minutes in MVPA (boys) and greater odds of adhering to screen time guidelines (OR, 1.96 (95%CI 1.02, 3.79) (girls) compared to living in regional centers. Sleep minutes were lower for students who spoke a language other than English at home (− 21.0 95%CI − 32.5, − 9.5). Only screen-time adherence for girls was associated with socioeconomic status. Conclusions : This study highlights low adherence to three Australian movement behavior guidelines among this large sample of regional and rural Victorian children. Large gender-differences in duration and adherence to MVPA and screen-time guidelines and declines with increasing age (all guidelines), highlight the need for population-wide interventions. What is Known: • Time spent in movement behaviors (moderate-to-vigorous physical activity, light-intensity physical activity, sedentary behavior and sleep are important for children’s health .• Few studies have examined device-measured movement behaviors and adherence to 24-h movement guidelines among regional children and whether this varies by gender, rurality and socioeconomic background . What is New: • This study found 22% of boys and 16% of girls met the 24-h movement recommendations, with 11% of boys and 9% of girls meeting no guideline .• Living in a medium or large rural town was associated with more moderate to vigorous physical activity in boys, and less screen-time among girls compared to those living in regional centers. Higher socioeconomic status was associated with less screen-time among girls .