School-level intra-cluster correlation coefficients and autocorrelations for children's accelerometer-measured physical activity in England by age and gender.

BACKGROUND: Randomised, cluster-based study designs in schools are commonly used to evaluate children's physical activity interventions. Sample size estimation relies on accurate estimation of the intra-cluster correlation coefficient (ICC), but published estimates, especially using accelerometry-measured physical activity, are few and vary depending on physical activity outcome and participant age. Less commonly-used cluster-based designs, such as stepped wedge designs, also need to account for correlations over time, e.g. cluster autocorrelation (CAC) and individual autocorrelation (IAC), but no estimates are currently available. This paper estimates the school-level ICC, CAC and IAC for England children's accelerometer-measured physical activity outcomes by age group and gender, to inform the design of future school-based cluster trials. METHODS: Data were pooled from seven large English datasets of accelerometer-measured physical activity data between 2002-18 (> 13,500 pupils, 540 primary and secondary schools). Linear mixed effect models estimated ICCs for weekday and whole week for minutes spent in moderate-to-vigorous physical activity (MVPA) and being sedentary for different age groups, stratified by gender. The CAC (1,252 schools) and IAC (34,923 pupils) were estimated by length of follow-up from pooled longitudinal data. RESULTS: School-level ICCs for weekday MVPA were higher in primary schools (from 0.07 (95% CI: 0.05, 0.10) to 0.08 (95% CI: 0.06, 0.11)) compared to secondary (from 0.04 (95% CI: 0.03, 0.07) to (95% CI: 0.04, 0.10)). Girls' ICCs were similar for primary and secondary schools, but boys' were lower in secondary. For all ages, combined the CAC was 0.60 (95% CI: 0.44-0.72), and the IAC was 0.46 (95% CI: 0.42-0.49), irrespective of follow-up time. Estimates were higher for MVPA vs sedentary time, and for weekdays vs the whole week. CONCLUSIONS: Adequately powered studies are important to evidence effective physical activity strategies. Our estimates of the ICC, CAC and IAC may be used to plan future school-based physical activity evaluations and were fairly consistent across a range of ages and settings, suggesting that results may be applied to other high income countries with similar school physical activity provision. It is important to use estimates appropriate to the study design, and that match the intended study population as closely as possible.

Predicting higher child BMI z-score and obesity incidence in Malaysia: a longitudinal analysis of a dynamic cohort study.

BACKGROUND: To target public health obesity prevention, we need to predict who might become obese i.e. predictors of increasing Body Mass Index (BMI) or obesity incidence. Predictors of incidence may be distinct from more well-studied predictors of prevalence, therefore we explored parent, child and sociodemographic predictors of child/adolescent BMI z-score and obesity incidence over 5 years in Malaysia. METHODS: The South East Asia Community Observatory in Segamat, Malaysia, provided longitudinal data on children and their parents (n = 1767). Children were aged 6-14 years at baseline (2013-14) and followed up 5 years later. Linear multilevel models estimated associations with child BMI z-score at follow-up, adjusting for baseline BMI z-score and potential confounders. Predictors included parent cardiometabolic health (overweight/obesity, central obesity, hypertension, hyperglycaemia), and socio-demographics (ethnicity, employment, education). Logistic multilevel models explored predictors of obesity incidence. RESULTS: Higher baseline BMI z-score predicted higher follow-up BMI z-score both in childhood to late adolescence (0.60; 95% CI: 0.55, 0.65) and early to late adolescence (0.76; 95% CI: 0.70, 0.82). There was inconsistent evidence of association between child BMI z-score at follow-up with parent cardiometabolic risk factors independent of baseline child BMI z-score. For example, maternal obesity, but not overweight, predicted a higher BMI z-score in childhood to early adolescence (overweight: 0.16; 95% CI: -0.03, 0.36, obesity: 0.41; 95% CI: 0.20, 0.61), and paternal overweight, but not obesity, predicted a higher BMI z-score in early to late adolescence (overweight: 0.22; 95% CI: 0.01, 0.43, obesity: 0.16; 95% CI: -0.10, 0.41). Parental obesity consistently predicted five-year obesity incidence in early to late adolescence, but not childhood to early adolescence. An adolescent without obesity at baseline with parents with obesity, had 3-4 times greater odds of developing obesity during follow-up (incidence OR = 3.38 (95% CI: 1.14-9.98, mother) and OR = 4.37 (95% CI 1.34-14.27, father) respectively). CONCLUSIONS: Having a higher BMI z-score at baseline was a stronger predictor of a higher BMI z-score at follow-up than any parental or sociodemographic factor. Targeting prevention efforts based on parent or sociodemographic factors is unwarranted but early childhood remains a key period for universal obesity prevention.

The status of active after-school clubs among primary school children in England (UK) after the COVD-19 lockdowns: implications for policy and practice.

BACKGROUND: Children's physical activity in England is more dependent on active clubs after the COVID-19 pandemic. However, it is unclear how the COVID-19 pandemic and related cost-of-living crisis have impacted on active club participation, costs and provision. This mixed-methods natural experiment explored school-based and community-based active clubs after lockdowns, using a unique combination of data sources to highlight implications for policy and practice post-COVID-19. METHODS: Cross-sectional questionnaire data on school and community active clubs were collected from 10-11-year-old children pre-COVID-19 in 2017-18 (N = 1,296; 50 schools), in 2021 (N = 393; 23 schools), and 2022 (N = 463; 27 schools). Club participation and attendance frequency were modelled using logistic and Poisson mixed effects models, adjusted for child age, gender and household education. In 2021 and 2022, parents reported expenditure on community-based clubs and schools provided data on school-based club provision, with data summarised descriptively. Qualitative data were collected in 2021 and 2022, with one-to-one interviews with school staff (N = 18) and parents (N = 43), and twelve child focus groups (N = 92), and analysed using the framework method. RESULTS: School-based active club participation was higher in 2022 compared to pre-pandemic (50% /43%), while community-based club participation was lower (74%/80%). Children attended 0.3 fewer clubs per week. Those from lower education households were less likely to participate in both types of active clubs, and girls less likely to attend community clubs. In 2022, the median cost of community and school club sessions were £6.67 and £3.88 respectively, with 52% of school-based clubs free to parents. Schools offered an average of 3.4 active clubs per week for 10-11-year-olds in 2022, with 34% partly/wholly subsidised. Qualitative analysis highlighted the impact of the cost-of-living crisis and COVID-19 pandemic on family resources, encouraging a shift to more affordable and convenient school-based active clubs, which negatively impacted the community-based active club environment. However, many schools struggled to meet this increased demand. CONCLUSIONS: Findings emphasise the importance for policymakers to support schools to meet increased demand for clubs and community clubs to increase affordable and convenient physical activity opportunities. Targeted support is needed to prevent socioeconomic and gender inequalities.

Short and medium-term effects of the COVID-19 lockdowns on child and parent accelerometer-measured physical activity and sedentary time: a natural experiment.

BACKGROUND: The COVID-19 pandemic has resulted in marked impacts on children's physical activity, with large reductions in moderate-to-vigorous physical activity (MVPA) reported during lockdowns. Previous evidence showed children's activity levels were lower and sedentary time higher immediately post-COVID lockdown, while there was little change in parental physical activity. We need to know if these patterns persist. METHODS: Active-6 is a natural experiment using repeated cross-sectional data conducted in two waves. Accelerometer data were collected on 393 children aged 10-11 and their parents from 23 schools in Wave 1 (June 2021-December 2021), and 436 children and parents from 27 schools in Wave 2 (January 2022-July 2022). These were compared to a pre-COVID-19 comparator group (March 2017-May 2018) of 1,296 children and parents in the same schools. Mean minutes of accelerometer-measured MVPA and sedentary time were derived for week- and weekend-days and compared across waves via linear multilevel models. We also analysed the date of data collection as a time series, to explore temporal patterns via generalised additive mixed models. RESULTS: There was no difference in children's mean MVPA in Wave 2 (weekdays: -2.3 min; 95% CI: -5.9, 1.3 and weekends: 0.6 min; 95% CI: -3.5, 4.6) when compared to the pre-COVID-19 data. Sedentary time remained higher than pre-pandemic by 13.2 min (95% CI:5.3, 21.1) on weekdays. Differences compared to pre-COVID-19 changed over time, with children's MVPA decreasing over winter, coinciding with COVID-19 outbreaks, and only returning to pre-pandemic levels towards May/June 2022. Parents' sedentary time and weekday MVPA was similar to pre-COVID-19 levels, with MVPA higher than pre-pandemic by 7.7 min (95% CI: 1.4, 14.0) on weekends. CONCLUSION: After an initial drop, children's MVPA returned to pre-pandemic levels by July 2022, while sedentary time remained higher. Parents' MVPA remained higher, especially at weekends. The recovery in physical activity is precarious and potentially susceptible to future COVID-19 outbreaks or changes in provision, and so robust measures to protect against future disruptions are needed. Furthermore, many children are still inactive, with only 41% meeting UK physical activity guidelines, and so there is still a need to increase children's physical activity.

The new normal for children's physical activity and screen viewing: a multi-perspective qualitative analysis of behaviours a year after the COVID-19 lockdowns in the UK.

BACKGROUND: The COVID-19 pandemic significantly impacted children's physical activity. Recent evidence indicated children's accelerometer-measured physical activity levels have, on average, returned to near pre-pandemic levels in 2022, though sedentary behaviour remains higher. However, insufficient physical activity levels among children continues to be a critical public health issue in the UK, with only 41% meeting physical activity guidelines. This study aimed to provide in-depth analysis of how the pandemic has shaped children's physical activity patterns beyond the short-term periods following lockdowns and identify the new challenges to engaging children in physical activity. METHODS: One-to-one interviews with parents (n = 22), school staff (n = 9), and six focus groups with children aged 10-11 years (n = 45) were conducted between February and July 2022. Topics explored changes to children's physical activity and sedentary behaviour patterns, including screen-viewing, and factors influencing any changes. The framework method was used for analysis. RESULTS: Five themes were generated. Theme 1 described residual lockdown habits, including increased screen-viewing within the home, while activities outside the home continued to feel less spontaneous. Theme 2 highlighted an interrupted development of social, emotional, and physical skills among children compared to what would be expected pre-pandemic. This coincided with Theme 3 which reflected increased mental health challenges among families, creating complex barriers to children's physical activity. A new normal for child physical activity was evoked and explored in Theme 4, with greater dependence on structured and organised activities. However, Theme 5 highlighted that girls and children with lower socio-economic position may be especially at risk of decreased physical activity. CONCLUSIONS: There is a new normal for children's physical activity that is characterised by increased dependence on structured and organised physical activities, such as active clubs, and less on unstructured and spontaneous physical activities, such as physical play. While this may suit many children, girls and children from lower socio-economic households face barriers to participating in the new normal. It is important that affordable and equitable opportunities are provided to all children to prevent physical activity and health inequalities.

Screen-viewing behaviours of children before and after the 2020-21 COVID-19 lockdowns in the UK: a mixed methods study.

BACKGROUND: Restrictions during the COVID-19 pandemic have led to increased screen-viewing among children, especially during strict periods of lockdown. However, the extent to which screen-viewing patterns in UK school children have changed post lockdowns is unclear. The aim of this paper is to examine how screen-viewing changed in 10-11-year-old children over the 2020-21 COVID-19 pandemic, how this compares to before the pandemic, and the influences on screen-viewing behaviour. METHODS: This is a mixed methods study with 10-11-year-olds from 50 schools in the Greater Bristol area, UK. Cross-sectional questionnaire data on minutes of weekday and weekend television (TV) viewing and total leisure screen-viewing were collected pre-COVID-19 in 2017-18 (N = 1,296) and again post-lockdowns in 2021 (N = 393). Data were modelled using Poisson mixed models, adjusted for age, gender, household education and seasonality, with interactions by gender and household education. Qualitative data were drawn from six focus groups (47 children) and 21 one-to-one parent interviews that explored screen-viewing behaviour during the pandemic and analysed using the framework method. RESULTS: Total leisure screen-viewing was 11% (95% CI: 12%-18%) higher post-lockdown compared to pre-COVID-19 on weekdays, and 8% (95% CI: 6%-10%) on weekends, equating to around 12-15 min. TV-viewing (including streaming) was higher by 68% (95% CI: 63%-74%) on weekdays and 80% (95% CI: 75%-85%) on weekend days. Differences in both were higher for girls and children from households with lower educational attainment. Qualitative themes reflected an unavoidable increase in screen-based activities during lockdowns, the resulting habitualisation of screen-viewing post-lockdown, and the role of the parent in reducing post-2020/21 lockdown screen-viewing. CONCLUSIONS: Although screen-viewing was higher post-lockdown compared to pre-COVID-19, the high increases reported during lockdowns were not, on average, sustained post-lockdown. This may be attributed to a combination of short-term fluctuations during periods of strict restrictions, parental support in regulating post-lockdown behaviour and age-related, rather than COVID-19-specific, increases in screen-viewing. However, socio-economic differences in our sample suggest that not all families were able to break the COVID-19-related adoption of screen-viewing, and that some groups may need additional support in managing a healthy balance of screen-viewing and other activities following the lockdowns.

Snacking and anxiety during the coronavirus disease (COVID-19) pandemic: A prospective cohort study.

Anxiety and snacking increased during the initial coronavirus disease 2019 (COVID-19) lockdowns, but it remains unknown whether this change in snacking persisted and if it related to anxiety levels. We used prospective data to examine changes in snacking frequency from t1 (eased restrictions in England in May-June 2020) to t2 (national lockdown in December 2020-March 2021), the association of anxiety (assessed by the Generalised Anxiety Disorder-7 questionnaire at t1) with the snacking change, and the mediating and moderating effects of disinhibition and flexible restraint (assessed by the Three Factor Eating Questionnaire in 2016-17). Analyses including 2128 adults (mean age 28.4 y) residing in England from the Avon Longitudinal Study of Parents and Children showed that snacking frequency increased over time (mean change 1.23 (95% CI 0.81, 1.65) snacks/wk). Linear regressions of snacking adjusted for sociodemographic covariates showed that having clinical levels of generalised anxiety at t1, versus not, was associated with 1.22 (95% CI 0.07, 2.37) more snacks/wk at t2. Disinhibition partially mediated the association between Generalised Anxiety Disorder and snacking (ßindirect = 0.15, 95% CI 0.01, 0.32), while there was no evidence that flexible restraint moderated the association (ß = 0.05, 95% CI -0.57, 0.66). Our longitudinal findings highlight a detrimental anxiety-snacking association partly operating via disinhibition, suggesting future research could target mitigating anxiety and disinhibited eating behaviours to benefit diet-related outcomes following the pandemic.

Accelerometer-measured physical activity and sedentary time among children and their parents in the UK before and after COVID-19 lockdowns: a natural experiment.

BACKGROUND: Restrictions due to the coronavirus disease 2019 (COVID-19) pandemic reduced physical activity provision for both children and their parents. Recent studies have reported decreases in physical activity levels during lockdown restrictions, but these were largely reliant on self-report methods, with data collected via unrepresentative self-report surveys. The post-pandemic impacts on children's activity levels remain unknown. A key question is how active children become once lockdown restrictions are lifted. METHODS: Active-6 is a repeated cross-sectional natural experiment. Accelerometer data from 1296 children aged 10-11 and their parents were collected in 50 schools in the Greater Bristol area, UK in March 2017-May 2018 (pre-COVID-19 comparator group), and compared to 393 children aged 10-11 and parents in 23 of the same schools, collected in May-December 2021. Mean minutes of accelerometer-measured moderate-to-vigorous physical activity (MVPA) were derived for weekdays and weekend and compared pre- and post-lockdown via linear multilevel models. RESULTS: After adjusting for seasonality, accelerometer wear time and child/parent demographics, children's mean weekday and weekend MVPA were 7.7 min (95% CI: 3.5 to 11.9) and 6.9 min (95% CI: 0.9 to 12.9) lower in 2021 than in 2018, respectively, while sedentary time was higher by 25.4 min (95% CI: 15.8 to 35.0) and 14.0 min (95% CI: 1.5 to 26.5). There was no evidence that differences varied by child gender or household education. There was no significant difference in parents' MVPA or sedentary time, either on weekdays or weekends. CONCLUSIONS: Children's MVPA was lower by 7-8 min/day in 2021 once restrictions were lifted than before the pandemic for all groups, on both weekdays and weekends. Previous research has shown that there is an undesirable age-related decline in children's physical activity. The 8-min difference reported here would be broadly comparable to the decline that would have previously been expected to occur over a three-year period. Parents' physical activity was similar to pre-pandemic levels. Our results suggest that despite easing of restrictions, children's activity levels have not returned to pre-pandemic levels. There is an urgent need to understand why these changes have occurred and how long they are maintained.

A multi-perspective qualitative exploration of the reasons for changes in the physical activity among 10-11-year-old children following the easing of the COVID-19 lockdown in the UK in 2021.

BACKGROUND: Active-6 is exploring how the COVID-19 pandemic has impacted physical activity behaviour among Year 6 children (aged 10-11 years) and their parents in Southwest England. Initial findings from the Active-6 project have shown a 7-8 min decrease in moderate-to-vigorous physical activity and an increase in sedentary behaviour among children following the easing of restrictions in the UK in latter half of 2021. This finding suggests that the pandemic has had a persistent impact on child physical activity behaviour. This paper explored the possible mechanisms behind these changes. METHODS: Interviews with parents (n = 21), members of school staff (n = 9) and focus groups with children aged 10-11 years (n = 47) were conducted between August and December 2021 to discuss the impact of the pandemic on child physical activity behaviour. The framework method was used for analysis. RESULTS: Five themes spanning two key stages of the pandemic were described. Three themes related to the period of lockdowns and fluctuating restrictions (March 2020 - April 2021). These included: Theme 1) Lockdown: A short-lived adventure; Theme 2) Access to facilities during restrictions; and Theme 3) The importance of the parent. A further two themes were identified related to the period following the gradual easing of restrictions in April 2021. These included: Theme 4) An overwhelming return to normal; and Theme 5) Reopening fatigue. CONCLUSIONS: The analysis suggested that feelings of novelty experienced during the initial stages of lockdown waned as restrictions were prolonged, creating an increasingly challenging period for parents and their children. However, during periods of restrictions, the importance of parental encouragement and access to appropriate facilities in the local and home environment helped facilitate physical activity. Following the easing of COVID-19 restrictions, emotional overwhelm and physical fatigue among children, stemming from a sedentary and socially isolated life in lockdown and other restrictions, were key contributors to the decreased moderate to vigorous physical activity and increased sedentary behaviour that was observed in a related quantitative study.

Association of BMI category with change in children's physical activity between ages 6 and 11 years: a longitudinal study.

BACKGROUND/OBJECTIVES: To examine the association of body mass index (BMI) with change in children's physical activity and sedentary time between ages 6 and 11. PARTICIPANTS: A total of 2132 children participated from 57 schools in Southwest England, from the B-PROACT1V study. METHODS: Mean minutes of MVPA and sedentary time per day were derived from accelerometer-based measurements at ages 6, 9 and 11. Linear multilevel models examined the association of BMI categories with MVPA and sedentary time between 6 and 11, adjusting for seasonality, wear time, gender and household education. Differences in change over time were examined using interaction terms. RESULTS: Average weekday MVPA decreased between ages 6 and 11 by 2.2 min/day/year (95% CI: 1.9 to 2.5), with a steeper decline at weekends. Average sedentary time increased at a rate of 12.9 min/day/year (95% CI: 12.2 to 13.6). There were no differences in mean levels of MVPA by BMI categories at age 6, but differences emerged as children aged, with the gap between children who were healthy weight and overweight increasing by 1.7 min/day (95% CI: 0.8-2.6) every year, and between healthy and obese by 2.0 min/day (95% CI: 0.9-3.1) each year. Children who were overweight/obese engaged in less average weekday sedentary time at age 6 than those of healthy weight, but the gap closed by age 11. CONCLUSION: MVPA declines and sedentary time increases on average for all children between ages 6 and 11. While there are no differences in activity levels by BMI category at age 6, differences in MVPA emerge over time for those who are overweight and obese. Developing interventions that support children to retain activity levels as they approach older childhood, particularly those who are overweight/obese could improve public health.

Multidimensional motivation for exercise: A latent profile and transition analysis.

OBJECTIVES: To: a) identify motivational profiles for exercise, using Self-Determination Theory as a theoretical framework, among a sample of parents of UK primary school children; b) explore the movement between motivational profiles over a five year period; and c) examine differences across these profiles in terms of gender, physical activity and BMI. DESIGN: Data were from the B-Proact1v cohort. METHODS: 2555 parents of British primary school children participated across three phases when the child was aged 5-6, 8-9, and 10-11. Parents completed a multidimensional measure of motivation for exercise and wore an ActiGraph GT3X + accelerometer for five days in each phase. Latent profile and transition analyses were conducted using a three-step approach in MPlus. RESULTS: Six profiles were identified, comprising different combinations of motivation types. Between each timepoint, moving between profiles was more likely than remaining in the same one. People with a more autonomous profile at a previous timepoint were unlikely to move to more controlled or amotivated profiles. At all three timepoints, more autonomous profiles were associated with higher levels of MVPA and lower BMI. CONCLUSIONS: The results show that people's motivation for exercise can be described in coherent and consistent profiles which are made up of multiple and simultaneous types of motivation. More autonomous motivation profiles were more enduring over time, indicating that promoting more autonomous motivational profiles may be central to facilitating longer-term physical activity engagement.

The association of school-related active travel and active after-school clubs with children's physical activity: a cross-sectional study in 11-year-old UK children.

BACKGROUND: Physical activity is associated with improved physical and mental health among children, but many children do not meet the recommended hour per day of moderate-to-vigorous-intensity physical activity (MVPA). The aim of this paper is to investigate participation in active after-school clubs and active travel to and from school at age 11 and estimate the average daily minutes of MVPA associated with active club attendance and active travel. METHODS: Accelerometer data were collected on three weekdays for 1296 11-year-old children in a cross-sectional study. Children reported attendance at active after-school clubs and how they travelled to and from school for each day of the week. To account for repeat days within child and clustering within schools we used multilevel models with random effects at the school and child level, and fixed effects for all covariates. We calculated odds ratios for participation in active after-school clubs and active travel for gender, measures of socio-economic position and BMI category. We also explored the association between active club attendance, active travel and daily average MVPA. RESULTS: Boys and girls were equally likely to attend active after-school clubs. Boys were more likely to travel to school using active modes. Attendance at active after-school clubs and active travel home were not associated with each other. Attending an active after-school club was associated with an additional 7.6 min (95% CI: 5.0 to 10.3) average MVPA on that day among both boys and girls. Active travel was associated with an additional 4.7 min (95% CI: 2.9 to 6.5) average MVPA per journey for boys and 2.4 min (95% CI: 1.0 to 3.7) for girls. CONCLUSIONS: Both active after-school clubs and active travel are associated with greater physical activity on the day that children participate in these, and we saw no evidence that those attending active clubs do so at the expense of active travel home afterwards. While the increased daily MVPA is small to moderate, active after-school clubs and active travel on multiple days of the week could make important contributions as part of complex interventions aimed at increasing population levels of physical activity in children.

Longitudinal associations between parents' motivations to exercise and their moderate-to-vigorous physical activity.

OBJECTIVES: This study is the first examination of the longitudinal associations between behavioural regulation and accelerometer-assessed physical activity in parents of primary-school aged children. DESIGN: A cohort design using data from the B-Proact1v project. METHOD: There were three measurement phases over five years. Exercise motivation was measured using the BREQ-2 and mean minutes of moderate-to-vigorous physical activity (MVPA) were derived from ActiGraph accelerometers worn for a minimum of 3 days. Cross-sectional associations were explored via linear regression models using parent data from the final two phases of the B-Proact1v cohort, when children were 8-9 years-old (925 parents, 72.3% mothers) and 10 to 11 years-old (891 parents, 72.6% mothers). Longitudinal associations across all three phases were explored using multi-level models on data from all parents who provided information on at least one occasion (2374 parents). All models were adjusted for gender, number of children, deprivation indices and school-based clustering. RESULTS: Cross-sectionally, identified regulation was associated with 5.43 (95% CI [2.56, 8.32]) and 4.88 (95% CI [1.94, 7.83]) minutes more MVPA per day at times 2 and 3 respectively. In the longitudinal model, a one-unit increase in introjected regulation was associated with a decline in mean daily MVPA of 0.52 (95% CI [-0.88, -0.16]) minutes per year. CONCLUSIONS: Interventions to promote the internalisation of personally meaningful rationales for being active, whilst ensuring that feelings of guilt are not fostered, may offer promise for facilitating greater long-term physical activity engagement in parents of primary school age children.

Associations within school-based same-sex friendship networks of children's physical activity and sedentary behaviours: a cross-sectional social network analysis.

BACKGROUND: Physical activity in children is associated with better physical and mental health but many children do not meet physical activity guidelines. Friendship groups are potentially an important influence on children's physical activity and sedentary time. This paper examines the association between children of physical activity and sedentary time in school-based same-sex friendship networks, for both moderate-to-vigorous intensity physical activity (MVPA) and sedentary time. Moreover, considering the methodological challenges of conducting and interpreting these analyses, we provide examples of how to analyse these data and interpret results to encourage further work in the area. METHODS: Accelerometer data for 1223 children, aged 8-9 years, were collected in 2015-2016 and analysed in 2017. Mean accelerometer minutes of MVPA and sedentary time were calculated. Children named up to four school friends and same-sex school-based friendship networks were constructed. Network models, which include correlation between friends, were fitted by sex. RESULTS: Both MVPA and sedentary time were found to be associated via the friendship networks, for both boys and girls. The network autocorrelation was 0.21 (95% CI: 0.15 to 0.26) for boys' MVPA, and 0.14 (95% CI: 0.07 to 0.21) for sedentary time. Network autocorrelation between girls was weaker, with 0.13 (95% CI: 0.06 to 0.19) for MVPA and 0.11 (95% CI: 0.05 to 0.17) for sedentary time. CONCLUSIONS: Physical activity and sedentary time of boys and girls are associated with the physical activity and sedentary time respectively of others within same-sex friendship networks, and these associations are comparable to other known factors. In this study, the correlation between friends was stronger for boys than girls, and stronger for MVPA than for sedentary time. These findings suggest that friendship networks play a part in understanding children's physical activity and sedentary time and could play a valuable role in developing effective interventions.

Profiles of children's physical activity and sedentary behaviour between age 6 and 9: a latent profile and transition analysis.

BACKGROUND: Physical activity is associated with improved physical and mental health among children. However, physical activity declines and sedentary time increases with age, and large proportions of older children do not meet the recommended hour per day of moderate-to-vigorous-intensity physical activity (MVPA). The aim of this paper is to identify profiles of children based on the complex relationship between physical activity and sedentary time at ages 6 and 9 and explore how those profiles are associated with other covariates and how they change over time. METHODS: Valid accelerometer data were collected for 1132 children aged 6 and 1121 at age 9, with 565 children with data at both ages. We calculated the proportions of total wear time spent in sedentary, light and MVPA activity on both weekdays and weekends. Latent profile (class) analysis was applied separately to the two age groups to identify activity profiles. We then used latent transition analysis to explore transitions between profiles at the two time points. RESULTS: We identified five profiles of activity at age 6 and six profiles at age 9. Although profiles were not directly equivalent, five classes captured similar patterns at both ages and ranged from very active to inactive. At both ages, active profiles, where the majority achieved the recommended MVPA guidelines, were more likely to be active at weekends than on weekdays. There was substantial movement between classes, with strongest patterns of movement to classes with no change or a decrease in MVPA. Transition between classes was associated with sex, BMI z-score, screen-viewing and participation in out-of-school activities. CONCLUSIONS: This paper is the first to apply latent profile analysis to the physical activity of UK children as they move through primary school. Profiles were identified at ages 6 and 9, reflecting different weekday and weekend patterns of physical activity and sedentary time. There was substantial movement between profiles between ages 6 and 9, mostly to no change or less active profiles. Weekend differences suggest that greater focus on how weekend activity contributes to an average of 60 min per day of MVPA across the week may be warranted.

Physical activity interventions in European primary schools: a scoping review to create a framework for the design of tailored interventions in European countries.

Introduction: Schools provide a unique environment to facilitate physical activity for children. However, many school-based physical activity interventions have not been effective. We propose a new approach, which allows schools to tailor interventions to their specific context. This scoping review aimed to identify intervention components from previous school-based physical activity interventions to form the basis of a tailored approach in a European setting. Methods: Joanna Briggs Institute guidelines for conducting scoping reviews were followed. European school-based intervention studies aimed at increasing physical activity in children aged 7-11 years published in English since 2015 were included. Databases searched were Ovid Medline, Embase, PsycINFO, Web of Science Social Sciences Citation Index, ERIC and British Education Index. Data was extracted on intervention components, context-related factors (geographical location, school size, child socioeconomic status and ethnicity), feasibility, acceptability and cost-effectiveness. A data-driven framework was developed to summarize the identified intervention components. Results: 79 articles were included, constituting 45 intervention studies. We identified 177 intervention components, which were synthesized into a framework of 60 intervention component types across 11 activity opportunities: six within the school day, three within the extended school day and two within the wider school environment. Interventions most frequently targeted physical education (21%), active and outdoor learning (16%), active breaks (15%), and school-level environmewnt (12%). Of the intervention components, 41% were delivered by school staff, 31% by the research team, and 24% by external organizations. Only 19% of intervention studies reported geographical location and only 10% reported school size. Participant ethnicity and socioeconomic information was reported by 15% and 25%, respectively. Intervention acceptability was reported in 51% of studies, feasibility in 49%, and cost effectiveness in 2%. Discussion: This review offers a first step in developing a future framework to help schools to develop context-specific, tailored interventions. However, there was a lack of reporting of contextual factors within the included studies, making it difficult to understand the role of context. Future research should seek to measure and report contextual factors, and to better understand the important aspects of context within school-based physical activity.

The impact of the COVID-19 pandemic on the physical activity environment in English primary schools: a multi-perspective qualitative analysis.

Background: The COVID-19 lockdowns and social distancing measures, including school closures, had a major impact on children's physical activity in England, with data showing an initial reduction in activity in the short-term post-lockdown phase of the pandemic followed by a recovery on average in the medium-term post-lockdown period. The school environment is an important context for child physical activity. The purpose of this study is to understand the changes that took place to school physical activity environments once schools reopened after lockdowns. This information will improve understanding of why changes to children's physical activity have occurred over the course of the pandemic and the implications for future promotion of physical activity in schools. Methods: Interviews with parents (n = 43), school staff (n = 18) and focus groups with 10- to 11-year-old children (participant n = 92) were conducted at two time points: between September-December 2021 and February-July 2022. Interview and focus group guides covered the impact of the pandemic on child physical activity and changes to this over time. The framework method was used for analysis. Results: Three themes and three subthemes were generated: (1) the return to school; (2) over-pressured staff and environment and (3) the uneven impact of the pandemic. Theme 3 consists of three subthemes: (a) retained pandemic policies, (b) impact on physical activity culture and (c) different children need different things. Limitations and future work: Conducting this research in schools during ongoing COVID-19 disruptions was a challenge and may have limited school and participant participation, particularly school staff. The parent interview sample is predominantly female, active and of higher socioeconomic status, so the experiences of male, less active and lower socioeconomic parents are limited. This study suggests that the impact of COVID-19 on child physical activity is uneven, affecting some children more than others. Future work is therefore needed to explore the details of this potential diverging experience. Conclusion: The COVID-19 pandemic, school closures and post-lockdown school policies have impacted upon primary school physical activity environments. The post-lockdown school environment is highly pressured, impacting the extent to which schools can support and encourage child physical activity. Future research is needed to further explore the impact of post-lockdown changes on physical activity environments in schools, particularly over the longer term, as schools continue to adapt post lockdowns. Strategies required to support school physical activity environments must be context specific and sensitive to these changes, pressures and needs. Funding: This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme as award number NIHR131847.

Schools are important spaces for children's physical activity. Children can be active in physical education lessons, break times, after-school clubs and travelling to school. School closures and other COVID-19 restrictions affected children's physical activity. We wanted to know how physical activity in primary schools might have changed since the pandemic. We spoke to school staff, pupils and parents two times after schools reopened. We asked about children's physical activity, and if or how this had changed over the course of the pandemic. We asked school staff about school policies around physical activity. When children went back to school, schools needed a 'recovery' approach. Children's academic, social and physical skills had been affected. For this time schools prioritised physical activity, but this was short-lived. Since then, schools have been highly pressured. They have had to 'catch up' on missed learning, staff are overloaded and some pupils are still affected by the lockdowns. Physical activity policies in schools have changed, but in many different ways. Some have kept social distancing policies; others feel their school culture has changed. Additionally, pupil ability and needs are more polarised. These factors have shaped, but are also shaped by, the high pressure in schools. Supporting changing child needs in highly pressured schools is hard for state primary schools. Changes to school physical activity policies need to be understood and evaluated. Strategies to ease pressure in schools are needed to support physical activity.

Exploring parents' physical activity motivation during the COVID-19 pandemic: a mixed-methods study from a self-determination theory perspective.

Background and objectives: The COVID-19 lockdowns impacted physical activity for all, but especially parents, because they had to balance home, work and leisure activities. Motivation for exercise is consistently shown to be associated with physical activity levels. Self-determination theory provides a framework through which the motivation for exercise and its social-contextual antecedents can be explored. The purpose of this study is to explore the role of motivation in determining physical activity in parents and carers of English primary school children before, during and after the COVID-19 lockdowns. Design, setting and participants: This study uses a mixed-methods design combining quantitative data and individual interviews. Participants were all parents/carers of children in year 6 (aged 10-11 years) at English primary schools in the United Kingdom. Methods: Quantitative data were collected on three occasions: between March 2017 and May 2018 (Wave 0, N = 1296), between May and December 2021 (Wave 1, N = 393) and between January and July 2022 (wave 2, N = 436). Motivation for exercise was assessed using the Behavioural Regulations in Exercise Questionnaire-2 and moderate-to-vigorous physical activity was estimated via waist-worn accelerometers. Data were analysed via regression models. Interviews with a subsample of parents (N = 43) were conducted on two occasions: between September and December 2021 and between February and July 2022. Interviews covered the impact of the pandemic on children and parents' physical activity and changes over time. This study focuses on discussions around the parents' own physical activity behaviour and their motivation. The framework method was used for analysis. Results: In separate linear regression models, intrinsic and identified regulation were associated with higher moderate-to-vigorous physical activity in waves 0 and 2. Amotivation was associated with lower moderate-to-vigorous physical activity in waves 0 and 2. In fully adjusted multivariable regression models, identified regulation was associated with a 4.9-minute increase in moderate-to-vigorous physical activity and introjected regulation was associated with a 2.3-minute decrease in moderate-to-vigorous physical activity at wave 0. Associations with moderate-to-vigorous physical activity were different in wave 2, with introjected regulation changing direction and a negative association with amotivation, although confidence intervals were wide due to smaller sample sizes. In the interviews, parents spoke of the effects that the COVID-19 lockdowns had on their motivation to be physically active in four theoretically driven themes: (1) motivation for physical activity, (2) perceived autonomy for physical activity, (3) perceived competence for physical activity and (4) perceived relatedness for physical activity. Limitations: The smaller sample sizes for waves 1 and 2 may have limited the ability to identify associations between behavioural regulations and moderate-to-vigorous physical activity post pandemic. Across all waves, parents were predominantly active, females, white and from higher socioeconomic areas and therefore may not reflect broader experiences. Conclusions and future work: Autonomous motivation, especially enjoyment and the importance for mental and physical well-being, was a key driver in keeping parents active during lockdowns and remains important for physical activity post lockdown, with introjected regulation potentially playing an increased role. Parents' interviews highlighted that while for some the lockdowns promoted autonomous motivation for exercise, others had enduring negative influences on their autonomy, competence and relatedness, which could be detrimental to their well-being. Strategies that focus on offering a range of novel activities for parents and that bring parent groups together may be effective. Funding: This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme as award number NIHR131847.

The COVID-19 pandemic affected parents' ability to be active. Motivation is important for taking part in physical activity. We wanted to know how motivation for exercise had changed since before the pandemic and how it might still impact parents' physical activity. We asked groups of parents of children in year 6 (aged 10­11 years) to complete a questionnaire and wear a device that measures physical activity. One group did this before the pandemic and two groups did this after the lockdowns. We also spoke to parents two times after schools reopened. We asked about their physical activity, what they felt helped or stopped them being active and how this changed during the pandemic. Motivation plays a part in how much physical activity parents do. Enjoying activities, being active because it is part of your identity and being active due to health make parents more active. Some parents felt they were more active in the first lockdown, as they had more time, freedom and a choice of new and exciting activities, while others felt the lockdowns led to them being less active. This was due to a loss of connection with other people and feeling less confident in their physical activity. This means that it is important that parents are well-supported in their physical activity post pandemic efforts to help parents be active should focus on creating opportunities for parents to try new activities opportunities for parents to be active together might lead to more physical activity, improved connections with others and better well-being.

School-level variation in children's moderate to vigorous intensity physical activity before and after COVID-19: a multilevel model analysis.

Background and objectives: Schools play a crucial role in facilitating physical activity among children, but the COVID-19 pandemic has affected both children's physical activity and the school environment. It is essential to understand between-school differences in children's physical activity post lockdown, to determine if and how the role of schools has changed. Design and participants: Active-6 is a natural experiment comparing postlockdown accelerometer-estimated physical activity to a pre-COVID-19 comparator group. Accelerometer and individual data were collected on 1296 children aged 10-11 pre-COVID-19 (2017-8), with school characteristics collected from the 50 schools they attended. Post lockdown, we collected accelerometer, individual and school data from 393 children in 23 of the same schools and 436 children in 27 of the same schools in 2021 (Wave 1) and 2022 (Wave 2), respectively. Methods: Sources of variation (between-school, between-pupil and within-pupil) in child weekday moderate to vigorous physical activity at each wave were modelled using linear mixed-effects models with school-level wave random coefficients. We extended the model to estimate the proportion of between-school variation explained by school policy, curriculum and physical environment factors and school-aggregated pupil characteristics. We also explored the extent to which postlockdown differences in moderate to vigorous physical activity were mediated by individual or school factors. Results: Between-school variation comprised 13% of the total variation pre-COVID-19, 7% in Wave 1 and 13% in Wave 2. School factors associated with moderate to vigorous physical activity were the following: whether physical education was compromised due to space (often: 9 minutes lower moderate to vigorous physical activity; sometimes: 5.4 minutes lower); high after-school club attendance (7 minutes higher moderate to vigorous physical activity for each additional club attended on average in the school); cycle training policy (4 minutes higher moderate to vigorous physical activity); and higher prevalence of active travel (1 minute higher moderate to vigorous physical activity for each 10% point increase in prevalence). These factors explained 22% of the between-school variation pre-COVID-19, and 72% at Wave 2. The relative importance changed, with cycle training policy and active travel being the most important pre-COVID-19 and cycle training policy, active after-school clubs and compromised physical education space most important in Wave 2. No factors were found to mediate the postlockdown differences in moderate to vigorous physical activity, except compromised physical education space, which had a suppressor effect in Wave 2. Limitations: Only 27 of the initial 50 schools participated post lockdown, limiting our ability to make comparisons across waves. Sample sizes were additionally affected by missing data for some variables. Conclusions and future work: While schools continue to play an important role in facilitating children's physical activity, the factors that contribute to this have changed post-COVID-19, with cycle training, active after-school clubs and ensuring physical education is prioritised even when space is limited now explaining nearly three-quarters of the between-school variation in children's moderate to vigorous physical activity. School-level interventions that focus on these areas, and policies that support them, may offer the potential to increase children's physical activity. Funding: This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme as award number NIHR131847.

Schools are important in helping children to be physically active. How active children are differs between schools. We wanted to know whether this has changed after the COVID-19 lockdowns. We also looked at features of the school, like equipment in the playground or being active in lessons, that might explain these differences. We collected activity data from 10- to 11-year-olds from 50 schools around Bristol (United Kingdom) before and after the COVID-19 lockdowns. Children also told us about how they travelled to school and whether they went to after-school sports or exercise clubs. We asked schools about their policies and lessons. Finally, we collected data on the playground and surroundings. In the first 6 months after lockdowns, schools had a much smaller role in children's activity. But after a year, schools were once again an important influence on how active children were. We found that the school features that affected children's activity had changed. Before the pandemic, the things that helped children most to be active were learning to ride a bike at school, and walking or cycling to school. After the pandemic, offering lots of after-school sports clubs was more important. Schools that struggled with physical education lessons because of a lack of space had fewer active pupils. Schools continue to play an important role in helping children be active. But this role has changed after the lockdowns. In the future, schools could help keep children active by offering plenty of after-school clubs and help children to learn to ride a bike. Also, it is important to make sure that physical education lessons are a priority, even when there is not much space.