Correlates of objectively measured physical activity and sedentary behaviour in English children

Determining factors of physical activity and sedentary behaviour in university students during the COVID-19 pandemic: A longitudinal study

INTRODUCTION

Historically, university students demonstrate poor movement behaviours that could negatively impact current and future health. Recent literature has focused on identifying determinants of physical activity (PA) and sedentary behaviour (SB) in this population to inform the development of intervention strategies. However, the COVID-19 pandemic substantially restricted movement behaviours in this population, meaning findings of previous research may no longer be applicable within the current societal context. The present study explored the longitudinal relationships between pre-pandemic psychological, behavioural and anthropometric factors, and the movement behaviours of UK university students nine months following the outbreak of COVID-19.

METHODS

Mental wellbeing (MWB), perceived stress (PS), body mass index (BMI), SB, and PA were assessed using an online self-report survey in 255 students prior to (October 2019) and nine months following (October 2020) the first confirmed case of COVID-19 in the UK. Path analysis was utilised to test relationships between pre-COVID mental wellbeing, perceived stress and BMI, and movement behaviours during the pandemic.

RESULTS

The fit of the path analysis model was good (χ2 = 0.01; CMIN = 0.10, CFI = 1.00, RMSEA = 0.00). Pre-covid MWB and PS positively influenced PA (β = 0.29; β = 0.24; P < 0.01) but not SB (β = -0.10; β = 0.00; P = 0.79) during the pandemic. Additionally, pre-pandemic SB and PA positively influenced SB and PA during the pandemic respectively (SB: β = 0.26; P < 0.01) (PA: β = 0.55; P < 0.01). Pre-pandemic BMI did not influence any measured variable during the pandemic (PA: β = 0.03 and P = 0.29; SB: β = 0.06 and P = 0.56), and there was no mediating effect of PA on SB during the pandemic (β = -0.26; P = 0.14).

CONCLUSION

These findings indicate that pre-covid mental health and movement behaviours had a direct positive influence on PA during the pandemic, but not SB. This longitudinal study demonstrates the influence that prior psychological and behavioural factors have in determining university students' response to periods of elevated stress and uncertainty, furthering our understanding of determinants of health-related behaviours in students.

Active School Commuting in School Children: A Narrative Review of Current Evidence and Future Research Implications

Active school commuting (ASC) has been proposed as a practical way to inculcate positive physical activity habits in children. This paper reviews the current evidence regarding ASC among children, highlights advances in research techniques and existing limitations in the field, and outlines future implications for research and promotion. A comprehensive literature search was conducted to identify English language studies on ASC among children aged 6-12 years, followed by a narrative review. ASC has witnessed a global decline, despite evidence of its contribution to physical activity levels. Context-dependent factors such as commuting distance and parental safety concerns are consistently identified as key determinants of ASC. Several promising interventions have been identified. Despite the limitations in intervention scope and quality, notable advancements in research techniques, such as multilevel regression and agent-based modelling, have been identified. Effective promotion of ASC to tackle childhood physical inactivity requires collaborative efforts among schools, parents, and the government, and should be tailored to address multilevel determinants within the local context. Future research should leverage recent advancements in research techniques to develop effective promotion strategies, while considering the context-dependent nature of ASC behaviours and addressing existing limitations, including the lack of standardised definitions and limited geographical and age coverage.

Comparison of habitual physical activity in French Bulldogs, Pugs and normocephalic dogs by accelerometry

Brachycephalic obstructive airway syndrome (BOAS) is a major welfare concern in flat-faced dog breeds. As BOAS causes respiratory difficulties and exercise intolerance, it can reduce dogs' daily quality of life (QOL). However, evaluation of QOL in dogs is difficult, and many owners perceive BOAS signs as 'normal' for the breed. Accelerometers that measure frequency, duration and intensity of activities can offer an objective way of evaluating dogs' daily activity and thereby deliver potential insights into QOL. The aim of this study was to assess habitual physical activity of 48 brachycephalic and 23 non-brachycephalic dogs using accelerometers. The accelerometers were used for one week and owners filled in a questionnaire regarding their dog's well-being and activities. Veterinary-assessed BOAS grading for brachycephalic dogs was determined. Compared with controls, more severely affected French Bulldogs and Pugs had significantly lower total activity counts and spent less time in high activity. In Pugs, mildly affected dogs were also less active, but age can be a contributing factor here, as older age decreased activity in Pugs and controls showed a wider age range. In French Bulldogs, those dogs with no or mild signs of BOAS did not differ from controls regarding their daily activity. In conclusion, accelerometers were easy to use for objective measurement of daily activity in bracycephalic dogs, although a degree of discomfort due to the collar was reported. Results showed that BOAS signs were associated with decreased habitual physical activity. These findings emphasise the importance of actions taken to reduce incidence of BOAS in brachycephalic breeds.

Correlates of domain-specific sedentary behaviors and objectively assessed sedentary time among elementary school children

Understanding the correlates of sedentary behavior among children is essential in developing effective interventions to reduce sitting time in this vulnerable population. This study aimed to identify correlates of domain-specific sedentary behaviors and objectively assessed sedentary time among a sample of children in Japan. Data from 343 children (aged 6-12 years) living in Japan were used. Domain-specific sedentary behaviors were assessed using a questionnaire. Total sedentary time was estimated using hip-worn accelerometers. Twenty-two potential correlates across five categories (parental characteristics, household indoor environment, residential neighborhood environment, school environment, and school neighborhood environment) were included. Multivariable linear regression models were used to identify correlates of domain-specific sedentary behaviors and objectively assessed sedentary time. Eight correlates were significantly associated with children's domain-specific sedentary behaviors: mother's and father's age, mother's educational level, having a video/DVD recorder/player, having a video console, having a TV one's own room, home's Walk Score^®, and pedestrian/cycling safety. No significant associations were found between potential correlates and accelerometer-based total sedentary time. These findings highlight that strategies to reduce children's sedentary time should consider the context of these behaviors. For example, urban design attributes such as perceived pedestrian and cycling safety can be improved to reduce children's car sitting time.

Activity Behaviors in British 6-Year-Olds: Cross-Sectional Associations and Longitudinal Change During the School Transition

BACKGROUND

To explore activity behaviors at school entry, we describe temporal/demographic associations with accelerometer-measured physical activity in a population-based sample of British 6-year-olds, and examine change from ages 4 to 6.

METHODS

A total of 712 six-year-olds (308 at both ages) wore Actiheart accelerometers for ≥3 (mean 6.0) days. We derived minutes per day sedentary (<20 cpm) and moderate to vigorous physical activity (MVPA, ≥460 cpm), also segmented across mornings (06:00 AM to 09:00 AM), school (09:00 AM to 3:00 PM), and evenings (3:00 PM to 11:00 PM). Using mixed effects linear regression, we analyzed associations between temporal/demographic factors and children's activity intensities at age 6, and change between ages 4 and 6.

RESULTS

Six-year-old children engaged in MVPA (mean [SD]): 64.9 (25.7) minutes per day (53% met UK guidelines). Girls did less MVPA than boys, particularly during school hours. Children were less active on weekends (vs weekdays) and more active on spring/summer evenings (vs winter). Longitudinally, 6-year-old children did less light physical activity (-43.0; 95% confidence interval, -47.5 to -38.4 min/d) but were more sedentary (29.4; 24.6 to 34.2), and engaged in greater MVPA (7.1; 5.2 to 9.1) compared to when they were aged 4.

CONCLUSION

Half of 6-year-old children met current activity guidelines; MVPA levels were lower in girls and at weekends. UK children became more sedentary but did more MVPA as they entered formal schooling. Physical activity promotion efforts should capitalize on these changes in MVPA, to maintain positive habits.

The Impact of Stand-Biased Desks on Afterschool Physical Activity Behaviors of Elementary School Children

The purpose of this secondary analysis was to assess whether students’ use of stand-biased desks during the school day influenced physical activity (PA) and sedentary behaviors (SB) during the afterschool period. By using a crossover design consisting of two 9-week intervention periods, 99 participants from grades 3, 4, and 6 were randomly assigned by their teacher to either a traditional (Group 1; sit−stand) or stand-biased (Group 2; stand−sit) desk in the classroom. The desk type then switched between intervention periods. Afterschool PA and SB were measured by accelerometry at baseline (fall) and following both intervention periods at post I (winter) and post II (spring). Independent sample t-tests and mixed-effects modeling were applied at a significance value of p < 0.05 to detect differences between groups. No significant differences in afterschool SB, light-intensity PA (LPA), or moderate- to vigorous-intensity PA (MVPA) were found between groups. There were also no significant two- or three-way interaction effects detected between desk assignment, time, and afterschool SB, LPA, or MVPA. Stand-biased desks in the classroom were not detrimental to children’s afterschool PA and SB.

Associations between socioeconomic position and young people's physical activity and sedentary behaviour in the UK: a scoping review

OBJECTIVE

To examine the evidence on the associations between socioeconomic position and young people's physical activity and sedentary behaviours in the UK.

DESIGN

Scoping review.

DATA SOURCES

PubMed, SCOPUS and Web of Science databases were searched for articles published up to and including January 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Observational studies in children and adolescents (aged 5-18 years) from the UK that had assessed associations between at least one indicator of socioeconomic position and at least one outcome of physical activity and/or sedentary behaviour.

DATA EXTRACTION AND SYNTHESIS

Data were extracted by one reviewer and 20% were double checked. Indicators of socioeconomic position were tabulated with domains of physical activity and sedentary behaviour.

RESULTS

Fifty-seven publications were included in the review; 37 publications from 19 studies (k=23) of children and 21 publications from 15 studies (k=23) of adolescents. Most studies were cross-sectional. 63% of studies of children, and 40% of studies of adolescents assessed Index of Multiple Deprivation. Eighteen studies measured physical activity in children, 13 measured sedentary behaviour. Eleven studies of adolescents included a measure of physical activity, 10 included a measure of sedentary behaviour. Among children and adolescents, the association between socioeconomic position and measures of either physical activity or sedentary behaviour was highly variable depending on the measure of both socioeconomic position used and the behavioural outcome, with the exception of higher family affluence which was consistently associated with higher reported physical activity among adolescents.

CONCLUSION

Physical activity and sedentary behaviours of children and adolescents in the UK are complex and influenced by multiple indicators of socioeconomic position that are, in most cases, different across age stages, outcomes examined and measurement tools. Greater consistency in the use and measures of socioeconomic position as well as outcomes of behaviour are required for robust country-specific meta-analyses.

The Associations of Active Travel to School With Physical Activity and Screen Time Among Adolescents: Do Individual and Parental Characteristics Matter?

Little is known about the relationship of active travel to school (ATS) with physical activity (PA) and screen time (ST) by individual and parental characteristics among adolescents, especially in China. To address the research gap, this study aimed to explore the difference of sex, age, living environment, parental occupation and education level in the relationship of ATS with PA and ST among students of grades 7–12 (aged 10–18 years) using cross-sectional data. In 13 cities of Hubei province, China, students from 39 public schools were recruited to engage in the survey. In total, 5,898 students (response rate = 89.6%) were invited into this study. Participants were required to report their ATS (including its types), PA and ST as well as sociodemographic information using a validated questionnaire. Descriptive analyses were used to report the information of all variables. Regression models were used to analyse the relationships of ATS and its types with PA and ST. In a total of 4,128 participants (boys: 50.9%; younger adolescents: 61.9%) included in the final analysis, the proportion of those with ATS was 47.3%. Regarding the types of ATS, walking accounted for over 30%, while cycling was 13.2%. Participants with ATS were more likely to have sufficient PA (OR = 1.26, 95% CI: 1.14–1.39), especially among boys, younger adolescents and those with lower parental education level. However, ATS was not associated with ST (OR = 0.94, 95% CI: 0.86–1.01). Participants with cycling had a higher odds ratio of being physically active (OR for cycling = 1.47, 95% CI: 1.27–1.70; OR for walking = 1.18, 95% CI: 1.06–1.32). The association of ATS types with PA and ST differed by gender, age, living environment and parental educational level as well as occupations. ATS may be a useful approach to increase PA among adolescents, but this should be explained by individual and parental characteristics.

Failure to Launch: Predictors of Unfavourable Physical Activity and Sedentary Behaviour Trajectories from Childhood to Adolescence: The Gateshead Millennium Study

In a previous study based on this cohort, only 15% of the participants belonged to a favourable physical activity/sedentary behaviour trajectory group (characterised by relatively high moderate–vigorous intensity physical activity and relatively low sedentary behaviour across childhood and adolescence). Since this favourable trajectory is protective against obesity, we aimed to identify factors associated with membership of this group. In this longitudinal study, 671 participants were assessed at ages 7, 9, 12 and 15 years. Participants’ demographics, socio-economic status (SES) and physical activity environment such as, sports club participation and commuting school were assessed at ages 7, 9 and 12 and analysed with favourable trajectory membership as an outcome using multinomial logistic regression. Sex (male) and SES (higher) were the non-modifiable factors associated with favourable trajectory group. Of the modifiable factors, commuting to school at age 7, a safe environment to play at age 7 and sports club participation at age 12 were all associated with more than 2.0 times increased probability of being in the most favourable trajectory. Future interventions to promote a favourable trajectory could focus on girls and participants with low SES. Promoting active commuting, safe local spaces to play and sports participation should also help lead to a favourable trajectory for physical activity and sedentary behaviour across childhood and adolescence.

Changes in Families' Leisure, Educational/Work and Social Screen Time Behaviours before and during COVID-19 in Australia: Findings from the Our Life at Home Study

This study aimed to understand differences in leisure, educational/work and social screen time behaviours experienced by parents and children due to COVID-19 lockdown restrictions, which may inform behaviour change strategies and policy in the transition to a COVID-normal life. Participants in the "Our Life at Home" study (n = 218 parents from Australia, 43.4 ± 6.8 years, 88% female) completed a cross-sectional online survey in April/May 2020. Parents recalled their own and their child (8.7 ± 2.0 years, 42% female) or adolescents (15.0 ± 1.5 years, 50% female) participation in nine screen time behaviours in the past month (during lockdown) and retrospectively for February 2020 (pre-lockdown), providing data on 436 individuals. Screen time behaviours included leisure (computer/laptop and tablet/smartphone for leisure, TV/videos/DVDs and game consoles); education/work (computer/laptop and tablet/smartphone for work/education); and social screen time (computer/tablet/smartphone for social communication with friends, family and work (parents only)). Wilcoxon signed-rank tests and effect sizes (r) compared the time spent in each behaviour pre-lockdown and during lockdown. Large differences were observed in social (parents: r = 0.41-0.57; children: r = 0.55-0.65; adolescents: r = 0.28-0.43) and education (children: r = 0.50-0.65 and adolescents: r = 0.25-0.37) behaviours. There were small or no differences in leisure time screen use. COVID-19 lockdown restrictions have impacted parent's and children's screen time, and future research and policy should consider strategies to support families to manage screen time.

Are Family Physical Activity Habits Passed on to Their Children?

Studies of the familial association of physical activity (PA) and sedentary behavior (SB) have increased in recent years. However, there is a lack of studies that have objectively examined the correlates between parents, grandparents, and childrens' PA. Therefore, the purpose of this study was to measure PA using accelerometers to determine the extent to which PA and SB correlate among parents, grandparents, and children. A sample of 169 children between 11 and 14 years (77 boys and 97 girls), 225 parents (98 males and 127 females), and 52 grandparents (16 males and 36 females) were recruited for the current study. Accelerometers RM42 (UKK Terveyspalvelut Oy, Tampere, Finland) were used to determine PA levels of children, parents, and grandparents. Epoch length was 6 s. Mothers' moderate-to-vigorous PA (MVPA) was associated with children's MVPA (p < 0.05). After adjusting for age, BMI (child), and educational status, the results remain the same. Results of linear regression analyses for boys' sedentary time showed that fathers' sedentary time was significantly associated with boys (p < 0.01), but not with girls. The association of grandmothers' and grandfathers' MVPA activity with that of children showed that grandparents' MVPA, when adjusted for age, BMI, and educational status, was not a significant predictor (p > 0.05) of children's MVPA (total sample). In contrast, grandfathers' sedentary behavior was a significant predictor (β = 0.269; p < 0.05) of children's sedentary behavior (total sample). The results of the current study suggest that parental involvement in PA, particularly by mothers, is important for children's PA and, accordingly, healthy outcomes.

Moderate-To-Vigorous Intensity Physical Activity and Sedentary Behaviour across Childhood and Adolescence, and Their Combined Relationship with Obesity Risk: A Multi-Trajectory Analysis

The combined role of objectively assessed moderate-vigorous intensity physical activity (MVPA) and sedentary behaviour (SB) is unclear in obesity prevention. This study aimed to identify latent groups for MVPA and SB trajectories from childhood to adolescence and examine their relationship with obesity risk at adolescence. From the Gateshead Millennium Study, accelerometer-based trajectories of time spent in MVPA and SB at ages 7, 9, 12, and 15 were derived as assigned as the predictor variable. Fat mass index (FMI), using bioelectrical impedance at age 15, was the outcome variable. From 672 children recruited, we identified three distinct multiple trajectory groups for time spent in MVPA and SB. The group with majority membership (54% of the cohort) had high MVPA and low SB at childhood, but MVPA declined and SB increased by age 15. One third of the cohort (31%) belonged to the trajectory with low MVPA and high time spent sedentary throughout. The third trajectory group (15% of the cohort) that had relatively high MVPA and relatively low SB throughout had lower FMI (-1.7, 95% CI (-3.4 to -1.0) kg/m2, p = 0.034) at age 15 compared to the inactive throughout group. High MVPA and low SB trajectories when combined are protective against obesity.

The Effect of Season and Neighbourhood-Built Environment on Home Area Sedentary Behaviour in 9-14 Year Old Children

There is little understanding of how the built environment shapes activity behaviours in children over different seasons. This study sought to establish how seasonal weather patterns, in a given year in a mid-western Canadian city, affect sedentary time (SED) in youth and how the relationship between season and SED are moderated by the built environment in their home neighbourhood. Families with children aged 9-14 years were recruited from the prairie city of Saskatoon, Canada. Location-specific, device-based SED was captured in children during three timeframes over a one-year period using GPS-paired accelerometers. Multilevel models are presented. Children accumulated significantly greater levels of SED in spring but significantly less SED in the fall months in comparison to the winter months. Children living in neighbourhoods with the highest density of destinations accumulated significantly less SED while in their home area in comparison to their counterparts, and this effect was more pronounced in the spring and summer months. On weekends, the rise in sedentariness within the home area was completely diminished in children living in neighbourhoods with the greatest number of destinations and highest activity friendliness. These results suggested that increasing neighbourhood amenities can lead to a reduced sedentariness of youth, though more so in the warmers months of the year.

Seasons, weather, and device-measured movement behaviors: a scoping review from 2006 to 2020

BACKGROUND

This scoping review summarized research on (a) seasonal differences in physical activity and sedentary behavior, and (b) specific weather indices associated with those behaviors.

METHODS

PubMed, CINAHL, and SPORTDiscus were searched to identify relevant studies. After identifying and screening 1459 articles, data were extracted from 110 articles with 118,189 participants from 30 countries (almost exclusively high-income countries) on five continents.

RESULTS

Both physical activity volume and moderate-to-vigorous physical activity (MVPA) were greater in summer than winter. Sedentary behavior was greater in winter than either spring or summer, and insufficient evidence existed to draw conclusions about seasonal differences in light physical activity. Physical activity volume and MVPA duration were positively associated with both the photoperiod and temperature, and negatively associated with precipitation. Sedentary behavior was negatively associated with photoperiod and positively associated with precipitation. Insufficient evidence existed to draw conclusions about light physical activity and specific weather indices. Many weather indices have been neglected in this literature (e.g., air quality, barometric pressure, cloud coverage, humidity, snow, visibility, windchill).

CONCLUSIONS

The natural environment can influence health by facilitating or inhibiting physical activity. Behavioral interventions should be sensitive to potential weather impacts. Extreme weather conditions brought about by climate change may compromise health-enhancing physical activity in the short term and, over longer periods of time, stimulate human migration in search of more suitable environmental niches.

Association of active school commuting with physical activity and sedentary behaviour among adolescents: A global perspective from 80 countries

OBJECTIVES

To examine associations of active school commuting (ASC) with time spent in physical activity (PA) and sedentary behaviour (SB) among adolescents.

DESIGN

Cross-sectional study.

METHODS

Global School-based Student Health Survey data from 277,833 adolescents aged 11-17 years (48.9% girls), collected during 2007-2016, were analysed. Adolescents were asked how many days per week they walked or bicycled to and from school, were physically active, and how much time they spent sitting on a typical day. ASC was defined as ≥3 days/week, meeting PA recommendations as ≥60min/day, high SB as leisure-time sitting ≥3h/day. Multilevel logistic regression analysis was used to estimate the odds ratios (OR) and 95% confidence intervals (CI) of the association estimates.

RESULTS

Adolescents who used ASC≥3 days/week had over double the odds of meeting PA recommendations (OR: 2.06, 95% CI: 2.01-2.12), after adjusting for a set of covariates. Adolescents who reported ASC≥3 days/week had 17% lower odds of reporting high SB (0.83, 0.81-0.85). The estimated OR of ASC and PA was 2.57 (2.31-2.86) in low-income and 1.84 (1.75-1.94) in high-income countries. Adolescents with ASC≥3 days/week had 22% lower odds of reporting high SB in African and Eastern Mediterranean regions (0.78, 0.73-0.84 and 0.75-0.82, respectively). Country-wise estimates of the associations are presented.

CONCLUSIONS

ASC is strongly and positively associated with PA recommendations and moderately with lower SB in adolescents. These estimates vary across WHO regions and by country's income. Promoting ASC has the potential to promote active lifestyle among adolescents around the globe.

Association among Weather Conditions, Ambient Air Temperature, and Sedentary Time in Chinese Adults

This study is aimed to quantify the association among weather conditions, ambient air temperature, and sedentary time in Chinese adults. The participants were 3,270 Chinese users of a wrist-worn activity tracker. Their daily activity data were collected using an algorithm based on raw data to determine the sedentary time. The data of ambient air temperature and weather were collected from the meteorological data released by China Central Meteorological Observatory. Two-level linear regression analyses showed that weather conditions had a significant influence on sedentary time in Chinese adults after adjustments for some covariates were made. When the weather condition changed from rainy days to sunny and cloudy days, sedentary time might decrease by about 6.89 and 5.60 min, respectively. In conclusion, weather conditions were independently associated with sedentary time in Chinese adults. The daily sedentary time was shorter on sunny and cloudy days than on rainy days.

Understanding and Influencing Occupational Sedentary Behavior: A Mixed-Methods Approach in a Multiethnic Asian Population

We aim to assess sedentary behavior (SB) and its determinants, as well as potential strategies to reduce SB among employees in a tertiary hospital in Singapore, using a mixed-methods approach grounded in the socioecological framework. All employees with email and security guards of a tertiary hospital in Singapore were invited to complete a questionnaire that captured sociodemographics and self-reported domain-specific SB. Environmental influences of occupational SB were assessed using an adapted version of the Checklist for Health Promotion Environments at the Worksite (CHEW). Focus group discussion (FGD) addressed perceptions, barriers, and strategies toward reducing workplace SB. Analyses were performed separately and integrated using an inductive comparative approach. The median occupational sitting time (n = 938) was 300 minutes/day, and highest among administrative staff (administrative, 421 minutes/day; allied health, 300 minutes/day; ancillary, 300 minutes/day; nursing, 120 minutes/day; medical/dental/others, 240 minutes/day; p value: <.001). The CHEW assessment identified poor physical and information environment contributing to occupational SB. FGDs confirmed an unsupportive environment and elicited barriers such as low SB awareness, nature of work, and workplace norms. Besides environmental approaches, participants suggested having face-to-face communication and social modelling to promote more breaks from sitting. This mixed-methods study among diverse professional groups of a tertiary hospital indicated a large amount of occupational SB, particularly among administrative staff. Raising awareness of the health risks of SB and building a supportive organizational culture, information, and physical environment emerged as significant factors. To reduce occupational SB, multicomponent interventions addressing these diverse factors are warranted.

Factors associated with accelerometer measured movement behaviours among White British and South Asian children aged 6-8 years during school terms and school holidays

OBJECTIVES

To investigate factors associated with movement behaviours among White British (WB) and South Asian (SA) children aged 6-8 years during school terms and holidays.

DESIGN

Cross-sectional.

SETTING

Three primary schools from the Bradford area, UK.

PARTICIPANTS

One hundred and sixty WB and SA children aged 6-8 years.

PRIMARY AND SECONDARY OUTCOMES

Sedentary behaviour (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) measured by accelerometry during summer, winter and spring and during school terms and school holidays. Data were analysed using multivariate mixed-effects multilevel modelling with robust SEs. Factors of interest were ethnicity, holiday/term, sex, socioeconomic status (SES), weight status, weekend/weekday and season.

RESULTS

One hundred and eight children (67.5%) provided 1157 valid days of data. Fifty-nine per cent of children were WB (n=64) and 41% (n=44) were SA. Boys spent more time in MVPA (11 min/day, p=0.013) compared with girls and SA children spent more time in SB (39 min, p=0.017) compared with WB children in adjusted models. Children living in higher SES areas were more sedentary (43 min, p=0.006) than children living in low SES areas. Children were more active during summer (15 min MVPA, p<0.001; 27 LPA, p<0.001) and spring (15 min MVPA, p=0.005; 38 min LPA, p<0.001) and less sedentary (-42 min and -53 min, p<0.001) compared with winter. Less time (8 min, p=0.012) was spent in LPA during school terms compared with school holidays. Children spent more time in MVPA (5 min, p=0.036) during weekend compared with weekdays. Overweight and obese children spent more time in LPA (21 min, p=0.021) than normal-weight children.

CONCLUSION

The results of our study suggest that significant child level factors associated with movement behaviours are ethnicity, sex, weight-status and area SES. Significant temporal factors are weekends, school holidays and seasonality. Interventions to support health enhancing movement behaviours may need to be tailored around these factors.

Adolescent offenders' current whereabouts predict locations of their future crimes

Knowing where crime is likely to happen can help prevent it. Here I investigate whether two basic mechanisms of human mobility-preferential return and spatial exploration-explain and predict where offenders commit future crimes. A sample of 843 adolescents reported their hourly whereabouts during four days. In line with findings from other sources and populations, their locations were concentrated and predictable. During the subsequent four years, 70 of the 843 were apprehended for committing one or more crimes. Compared to others, these 70 future offenders had visited slightly more different locations. However, their action radius and the predictability of their whereabouts had been very similar to those who would not become offenders. The offenders perpetrated most of their crimes around places they had visited before, including places where they previously offended. These findings show that the predictability of human mobility applies to offending and to offenders as well, and helps us understand and forecast where they will commit future crimes. They may prove particularly useful in criminal investigations, as they suggest that police should generally prioritize suspects who are familiar with the location of the crime and its environs, either because of their legal routine activities or because of their prior offences.

Child- and Parent-Related Correlates of Total and Prolonged Sedentary Time in 5- to 6-Year-Old Children

The primary aim was to examine child- and parent-related correlates of accelerometer-assessed overall total and prolonged (i.e., accumulated in bouts of ≥10 consecutive minutes) sedentary time (SED) in 5- to 6-year-old children. Second, child- and parent-related correlates of total and prolonged SED during weekend days and the after school period were examined, as associations with parent-related correlates may be stronger during these periods. SED and moderate-to-vigorous-intensity physical activity (MVPA) were assessed by ActiGraph accelerometers in children (n = 836) and one of their parents/carers. Parents completed a questionnaire examining potential parent-related correlates. Multilevel models examined associations between potential correlates and children’s total and prolonged SED. Children’s MVPA was the only correlate that was consistently negatively associated with both total and prolonged SED across the different time periods (overall, after school, and weekend days). Higher total SED in parents was associated with higher overall total SED and weekend total SED in children. Higher body mass index z-scores of children were associated with lower overall total and prolonged SED. Girls had lower prolonged SED after school than boys. Older children had lower total SED during the weekend. In conclusion, few potential correlates were associated with young children’s total or prolonged SED and most associations differed by time period.

Associations of physical activity with childhood asthma, a population study based on the WHO - health behaviour in school-aged children survey

Background

Asthma in paediatric populations is one of the highest public health concerns. In this study of children and adolescents, we hypothesized that low levels of physical activity (PA) would show associations with asthma that vary by asthma outcome. The objective was to assess whether PA was associated with ever asthma and/or current asthma.

Methods

Analyses were based on 4824 Danish schoolchildren aged 11–15 years old (48.7% boys) participating in the HBSC survey. The study variables were (1) physician-diagnosed asthma (ever asthma) and (2) physician-diagnosed asthma plus wheezing and/or physician or hospital consultation for wheezing (current asthma). Associations with PA by gender were analysed with multivariate logistic regression using the “variance covariance (vce) cluster” method.

Results

The prevalence of ever asthma was 14.3% (boys) and 12.8% (girls), and that of current asthma was 6.8% (boys) and 7.0% (girls). Boys with current asthma showed important differences in low and high PA. We found inverse associations between low PA and ever asthma, odds ratio [95% confidence interval] male: .55 [.30; .99] and female: .47 [.24; .93], and current asthma, male: .27 [.12; .60] (P linear trend = .007) and female: .32 [.11; .94].

Conclusions

The lowest activity levels showed significant inverse associations with asthma, regardless of the definition. For boys, the more stringent (current asthma) of the two paediatric asthma definitions revealed a significant trend with PA, and the direction of associations shifted to positive as weekly PA increased.

Electronic supplementary material

The online version of this article (10.1186/s40733-018-0042-9) contains supplementary material, which is available to authorized users.

Correlates of intensity-specific physical activity in children aged 9-11 years: a multilevel analysis of UK data from the International Study of Childhood Obesity, Lifestyle and the Environment

OBJECTIVES

Physical activity (PA) can provide numerous physical and psychological health gains, yet a low proportion of children in England are sufficiently active to accrue benefit. Analysing the correlates of PA from a socioecological perspective may help to identify factors that promote versus discourage PA. The purpose of the present study was to: (1) assess the relationships between a wide range of potential correlates and intensity-specific PA and (2) explore which correlates are associated with meeting government PA guidelines.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional study on children aged 9-11 years from the South West of England (n=425; 183 males).

OUTCOME MEASURES

A mixture of self-reported and objective measures (eg, body mass index (BMI), accelerometer-derived PA, self-reported sport participation, etc) were collected from child participants, parents and school teachers. After adjusting for covariates (ie, age, sex and accelerometer wear time), multilevel modelling techniques were employed to examine the relationships between potential correlates and light-intensity, moderate-intensity and vigorous-intensity PA, as measured with an ActiGraph GT3X+ accelerometer. Generalised linear mixed modelling was used to analyse the correlates associated with government-recommended levels of PA.

RESULTS

Computer use shared a negative association whereas parent support for PA showed a positive relationship with light-intensity PA. In terms of moderate-intensity PA, computer use and BMI z-score shared a negative association whereas positive relationships were found for sport participation, active transport and for outdoor time after school. Children at schools with 25%-49% of pupils attending school sport/PA clubs did more moderate-intensity PA than those attending schools with lower participation rates. For vigorous-intensity PA, a negative relationship was observed for BMI z-score, and positive associations for self-efficacy, active transport, parent support and the presence of crossing guards on routes to school. Correlates associated with meeting the PA guidelines were BMI z-score (negative), sport participation, active transport and outdoor time after school (all positive).

CONCLUSION

Results demonstrate that factors pertaining to the individual, home and school environment may play an important role in understanding the correlates of differing PA intensities in children.

TRIAL REGISTRATION NUMBER

NCT01722500.

Correlates of intensity-specific physical activity in children aged 9-11 years: a multilevel analysis of UK data from the International Study of Childhood Obesity, Lifestyle and the Environment

OBJECTIVES

Physical activity (PA) can provide numerous physical and psychological health gains, yet a low proportion of children in England are sufficiently active to accrue benefit. Analysing the correlates of PA from a socioecological perspective may help to identify factors that promote versus discourage PA. The purpose of the present study was to: (1) assess the relationships between a wide range of potential correlates and intensity-specific PA and (2) explore which correlates are associated with meeting government PA guidelines.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional study on children aged 9-11 years from the South West of England (n=425; 183 males).

OUTCOME MEASURES

A mixture of self-reported and objective measures (eg, body mass index (BMI), accelerometer-derived PA, self-reported sport participation, etc) were collected from child participants, parents and school teachers. After adjusting for covariates (ie, age, sex and accelerometer wear time), multilevel modelling techniques were employed to examine the relationships between potential correlates and light-intensity, moderate-intensity and vigorous-intensity PA, as measured with an ActiGraph GT3X+ accelerometer. Generalised linear mixed modelling was used to analyse the correlates associated with government-recommended levels of PA.

RESULTS

Computer use shared a negative association whereas parent support for PA showed a positive relationship with light-intensity PA. In terms of moderate-intensity PA, computer use and BMI z-score shared a negative association whereas positive relationships were found for sport participation, active transport and for outdoor time after school. Children at schools with 25%-49% of pupils attending school sport/PA clubs did more moderate-intensity PA than those attending schools with lower participation rates. For vigorous-intensity PA, a negative relationship was observed for BMI z-score, and positive associations for self-efficacy, active transport, parent support and the presence of crossing guards on routes to school. Correlates associated with meeting the PA guidelines were BMI z-score (negative), sport participation, active transport and outdoor time after school (all positive).

CONCLUSION

Results demonstrate that factors pertaining to the individual, home and school environment may play an important role in understanding the correlates of differing PA intensities in children.

TRIAL REGISTRATION NUMBER

NCT01722500.

Correlates of compliance with recommended levels of physical activity in children

The purpose of this study was to describe children’s daily compliance with moderate-to-vigorous physical activity (MVPA) recommendations across a week in different parts of the world, and to identify individual- and school-level correlates that may explain differences in daily MVPA compliance. The sample included 6553 children aged 9–11 years from 12 countries, and multilevel statistical analyses were used, including both child- and school-level variables. Most children did not comply with the MVPA guidelines on a daily basis: Chinese children complied the least, whereas Finnish, Australian, Colombian, UK, and Kenyan children complied the most. Boys (rate ratio [RR] = 1.47) and children with higher unhealthy diet scores (RR = 1.08) complied more, but overweight/obese children (RR = 0.81), earlier maturing children (RR = 0.93), and those who spent more time in screen activities (RR = 0.98) and sleeping (RR = 0.96) had the lowest compliance. At the school level, children with access to playground or sport equipment (RR = 0.88, for both) tended to comply less, whereas those with access to a gymnasium outside the school hours complied more with the MVPA guidelines (RR = 1.14). Significant between-country differences in children’s daily MVPA compliance were observed, reflecting not only site characteristics, but also the importance of individual traits and local school contexts.

Pragmatic evaluation of the Go2Play Active Play intervention on physical activity and fundamental movement skills in children

Active play is a novel approach to addressing low physical activity levels and fundamental movement skills (FMS) in children. This study aimed to determine if a new school-based, 'Go2Play Active Play' intervention improved school day physical activity and FMS. This was a pragmatic evaluation conducted in Scotland during 2015-16. Participants (n = 172; mean age = 7 years) were recruited from seven primary schools taking part in the 5-month intervention, plus 24 participants not receiving the intervention were recruited to act as a comparison group.189 participants had physical activity measured using an Actigraph GT3X accelerometer at baseline and again at follow-up 5 months later. A sub-sample of participants from the intervention (n = 102) and comparison (n = 21) groups had their FMS assessed using the Test of Gross Motor Development (TGMD-2) at baseline and follow-up. Changes in school day physical activity and FMS variables were examined using repeated measures ANOVA. The main effect was 'group' on 'time' from baseline to follow-up. Results indicated there was a significant interaction for mean counts per minute and percent time in sedentary behavior, light intensity physical activity and moderate to vigorous physical activity (MVPA) (all p < 0.01) for school day physical activity. There was a significant interaction for gross motor quotient (GMQ) score (p = 0.02) and percentile (p = 0.04), locomotor skills score and percentile (both p = 0.02), but no significant interaction for object control skills score (p = 0.1) and percentile (p = 0.3). The Go2Play Active Play intervention may be a promising way of improving physical activity and FMS but this needs to be confirmed in an RCT.

Why Do Children Engage in Sedentary Behavior? Child- and Parent-Perceived Determinants

Todays children spend a large amount of their time sedentary. There is limited evidence on the determinants of sedentary behavior in children, and qualitative studies are especially lacking. Therefore, this study aimed to explore determinants of children’s sedentary behavior from the child- and parent perspective. Qualitative data were collected during concept mapping sessions with four groups of 11–13 years old children (n = 38) and two online sessions with parents (n = 21). Children and parents generated sedentary behavior motives, sorted related motives, and rated their importance in influencing children’s sedentary time. Next, multidimensional scaling and hierarchical cluster analysis was performed to create clusters of motives resulting in a concept map. Finally, the researchers named the clusters in the concept map. Concept maps of children yielded eight to ten perceived determinants, and concept maps of parents six to seven. Children and parents identified six similar potential determinants, and both rated as important: Sitting because… “it is the norm (I have to)”, and “I can work/play better that way”. In addition, children rated “there is nobody to play with” as an important potential determinant for engaging in sedentary behavior. The most important child- and parent perceived determinants were related to the social/cultural and physical environment, indicating that these are promising targets for future interventions.

Parenting Practices and Children's Physical Activity: An Integrative Review

The purpose of this integrative review was to analyze the state of science concerning the influence of parenting practices on children's physical activity (PA) levels. A total of 38 studies met the inclusion criteria after full-text review. The body of research is limited in experimental designs with only three studies measuring the influence of the intervention on parenting practices. Seven of the 30 quantitative studies (23.3%) found significant associations between parental role modeling of PA and children's PA levels. Seven of the eight (87.5%) qualitative studies identified parental role modeling of PA as important in promoting children's PA. Sixteen of the 30 (53.3%) quantitative studies found that parental support of PA was significantly associated with children's PA. Five of the eight (62.5%) qualitative studies identified logistic support as supporting PA in children. The science could be expanded by the development of randomized controlled trials aimed at this area.

Setting them up for lifetime activity: Play competence perceptions and physical activity in young children

OBJECTIVES

Possessing positive physical perceived competence is important for physical activity in older children. Young children are primarily physically active through play-based behaviour rather than through organised sports and activities, so understanding how play perceptions might influence physical activity behaviour is important. The study purpose was to assess if perceived active play competence is associated with young children's physical activity.

DESIGN

Cross sectional study.

METHODS

This paper uses two different samples drawn from the same Australian city, both collected in 2013. The first sample included 152 children (49% boys) aged 4-5 years (M=4.7, SD=0.47), the second sample included 78 children (55% boys) aged 5-8 years (M=6.6, SD=0.93). The Pictorial Scale of Perceived Movement Skill Competence was used to assess children's perceived competence in six skill-related play activities. Moderate- to vigorous-intensity physical activity (MVPA) was assessed for 8 consecutive days via accelerometers. A general linear model with the mean minutes in MVPA per day as the outcome, perceived play competence as the independent variable and adjusting for relevant confounders was performed in each sample.

RESULTS

Perceived active play competence was not related to MVPA min/day (B=0.44, p=0.323) in the younger sample, but was in the older sample (B=1.53, p=0.026), explaining 24% of adjusted variance.

CONCLUSIONS

Positive findings in the older sample show school-aged children need exposure to play based activities in order to develop the positive self-perception needed to engage in MVPA every day.

Timing of the decline in physical activity in childhood and adolescence: Gateshead Millennium Cohort Study

Background and aim

There is a widely held and influential view that physical activity begins to decline at adolescence. This study aimed to identify the timing of changes in physical activity during childhood and adolescence.

Methods

Longitudinal cohort study (Gateshead Millennium Study) with 8 years of follow-up, from North-East England. Cohort members comprise a socioeconomically representative sample studied at ages 7, 9, 12 and 15 years; 545 individuals provided physical activity data at two or more time points. Habitual total volume of physical activity and moderate-to-vigorous intensity physical activity (MVPA) were quantified objectively using the Actigraph accelerometer over 5–7 days at the four time points. Linear mixed models identified the timing of changes in physical activity across the 8-year period, and trajectory analysis was used to identify subgroups with distinct patterns of age-related changes.

Results

Four trajectories of change in total volume of physical activity were identified representing 100% of all participants: all trajectories declined from age 7 years. There was no evidence that physical activity decline began at adolescence, or that adolescent declines in physical activity were substantially greater than the declines during childhood, or greater in girls than boys. One group (19% of boys) had relatively high MVPA which remained stable between ages 7 and15 years.

Conclusions

Future policy and research efforts to promote physical activity should begin well before adolescence, and should include both boys and girls.

Physical activity, sedentary behaviour, and socioeconomic status among Finnish girls and boys aged 6-8 years

We studied differences in physical activity (PA), sedentary behaviour (SB), and the types of PA and SB between Finnish girls and boys and children from different socioeconomic backgrounds (SES). We assessed PA, SB, parental education, and household income using detailed questionnaires in a representative population sample of 486 children (238 girls, 248 boys) aged 6-8 years. Girls spent on average 1.7 h/day and boys 2.0 h/day in total PA (p = 0.002). Altogether 66% of girls and 54% of boys had less than 2 h of total PA per day (p = 0.012). Girls had lower levels of unsupervised PA (45 vs. 54 min/day, p = 0.001), supervised PA (1.5 vs. 1.9 h/week, p = 0.009), and PA during school recess (1.8 vs. 1.9 h/week, p = 0.032) than boys. Girls had higher levels of total SB (3.8 vs. 3.4 h/day, p = 0.015) but lower levels of screen-based SB (1.5 vs. 1.9 h/day, p < 0.001) than boys. Lower parental education and household income were associated with lower levels of supervised PA in girls (p = 0.011 and p = 0.008, respectively) and in boys (p = 0.006 and p = 0.003, respectively). Lower parental education and household income were also related to higher levels of screen-based SB in boys (p = 0.005 and p < 0.001, respectively) but not in girls. Girls have lower levels of total, unsupervised, and supervised PA, PA during recess, and screen-based SB but higher levels of total SB than boys. Lower parental education and household income are associated with lower levels of supervised PA in both genders and higher levels of screen-based SB in boys.

Physical activity, sedentary behavior and their correlates in children with Autism Spectrum Disorder: A systematic review

Autism Spectrum Disorder affects up to 2.5% of children and is associated with harmful health outcomes (e.g. obesity). Low levels of physical activity and high levels of sedentary behaviors may contribute to harmful health outcomes. To systematically review the prevalence and correlates of physical activity and sedentary behaviors in children with Autism Spectrum Disorder, electronic databases (PsycINFO, SPORTDiscus, EMBASE, Medline) were searched from inception to November 2015. The review was registered with PROSPERO (CRD42014013849). Peer-reviewed, English language studies were included. Two reviewers screened potentially relevant articles. Outcomes of interest were physical activity and sedentary behaviour levels and their potential correlates. Data were collected and analysed in 2015. Of 35 included studies, 15 reported physical activity prevalence, 10 reported physical activity correlates, 18 reported sedentary behavior prevalence, and 10 reported sedentary behavior correlates. Estimates of children’s physical activity (34–166 mins/day, average 86 mins/day) and sedentary behavior (126–558 mins/day in screen time, average 271 mins/day; 428–750 mins/day in total sedentary behavior, average 479 mins/day) varied across studies. Age was consistently inversely associated, and sex inconsistently associated with physical activity. Age and sex were inconsistently associated with sedentary behavior. Sample sizes were small. All but one of the studies were classified as having high risk of bias. Few correlates have been reported in sufficient studies to provide overall estimates of associations. Potential correlates in the physical environment remain largely unexamined. This review highlights varying levels of physical activity and sedentary behavior in children with Autism Spectrum Disorder. Research is needed to consistently identify the correlates of these behaviors. There is a critical need for interventions to support healthy levels of these behaviors.

Relationship between Sedentariness and Moderate-to-Vigorous Physical Activity in Youth: A Multivariate Multilevel Study

This study aimed to jointly analyse moderate-to-vigorous physical activity (MVPA) and sedentariness, and their correlates, in children within their school contexts, using a multivariate multilevel approach. The sample comprises 499 Portuguese children (284 girls) from 23 schools. MVPA and sedentary time were estimated by accelerometer. A set of predictor variables from both child and school levels was tested. Overall, schools explained a small amount of the total variance in both MVPA (5.6%) and sedentariness (3.2%), and a correlation coefficient of -0.45 (p < 0.05) was found between MVPA and sedentariness at the child level. Number of siblings and socioeconomic status (SES) were significantly associated with both sedentariness (SES: β = 2.372 ± 1.183; siblings: β = -8.127 ± 2.759) and MPVA (SES: β = -1.535 ± 0.421; siblings: β = 2.822 ± 0.977), but with opposite signs. Body Mass Index (BMI) (β = -4.804 ± 1.898) and sex (male) (β = 21.561 ± 3.496) were only associated with MVPA. None of the school correlates were statistically significant in their joint effects to simultaneously explain sedentariness and MVPA. These results suggest that although MVPA and sedentariness may be different constructs, they are correlated and this should be taken into account when designing strategies to reduce children's sedentariness and increase their MVPA. In addition, the small effect of the school context on this relationship highlights the important roles of child and family characteristics.

Physical self-efficacy is associated to body mass index in schoolchildren

OBJECTIVE

The present study aimed to investigate the relationship between physical self-efficacy and body mass index in a large sample of schoolchildren.

METHODS

The Perceived Physical Ability Scale for Children was administered to 1560 children (50.4% boys; 8-12 years) from three different countries. Weight and height were also recorded to obtain the body mass index.

RESULTS

In agreement with the literature, the boys reported greater perceived physical self-efficacy than girls. Moreover, the number of boys who are obese is double that of girls, while the number of boys who are underweight is half that found in girls. In the linear regression model, the increase in body mass index was negatively related to the physical self-efficacy score, differently for boys and girls. Furthermore, age and nationality also were predictors of low physical self-efficacy only for girls.

CONCLUSION

The results of this study reinforce the importance of psychological aspect of obesity, as the perceived physical self-efficacy and body mass index were negatively associated in a sample of schoolchildren for boys and girls.

Objectively Measured Sedentary Time in Children and Their Parents

Background

No studies have examined associations in objectively measured sedentary time between parents and young people using activPAL posture sensors, which provide a more accurate estimate of sedentary time compared to accelerometer-based devices. This study examines patterns and associations of activPAL measured sedentary time and number of sedentary breaks on weekdays and weekend days in preschool (2–4 yrs), primary (5–11 yrs) and secondary school aged children (12–17 yrs) and their parents.

Methods

51 parents (16 M, 35 F; mean age 39 (+/−8) yrs) and 51 children (28 M, 23 F; mean age 9 (+/−5) yrs) wore an activPAL monitor for 7 days to measure time spent sedentary and number of breaks in sedentary time. Data was assessed by Pearson's correlations and t-tests.

Results

Secondary school children spent a greater percentage of their day sedentary (64.5 (+/−8.5) %) than preschool (57.4 (+/−7.3) %) and primary school children (57.2 (+/−5) %). For the secondary school parent dyad, there were no significant positive associations for time sedentary (r = −0.167, p = 0.494) and percentage of day sedentary (r = −0.247, p = 0.308). For the primary school parent dyad, there were medium, but non-significant positive correlations for time sedentary (r = 0.38, p = 0.146) and percentage of day sedentary (r = 0.363, p = 0.167). For the preschool parent dyad, there were medium—large positive correlations for percentage of waking day sedentary at weekends (r = 0.479, p = 0.083) and number of sedentary breaks (r = 0.648, p = 0.012) at weekends.

Conclusions

There were positive associations in sedentary time between primary school children and their parents, and between preschool children and their parents at the weekend. Thus, interventions aimed at reducing sedentary time of parents and children together, particularly at the weekend for young children, may be effective in these age groups. Secondary school children were more sedentary and had fewer sedentary breaks than younger children, thus interventions should promote breaks in sedentary time as well as reducing total sedentary time in this age group.

Does home equipment contribute to socioeconomic gradients in Australian children's physical activity, sedentary time and screen time?

BACKGROUND

Activity behaviours (physical activity, sedentary time and screen time) have been linked to health outcomes in childhood. Furthermore, socioeconomic disparities have been observed in both children's activity behaviours and health outcomes. Children's physical home environments may play a role in these relationships. This study aimed to examine the associations and interactions between children's physical home environment, socioeconomic status and moderate-to-vigorous physical activity, sedentary time and screen time.

METHODS

Australian children (n = 528) aged 9-11 years from randomly selected schools participated in the cross-sectional International Study of Childhood Obesity, Lifestyle and the Environment. Children's physical home environment (access to equipment), socioeconomic status (household income and parental education) and demographic variables (gender and family structure) were determined by parental questionnaire. Moderate-to-vigorous physical activity and sedentary time were measured objectively by 7-day 24-h accelerometry. Screen time was obtained from child survey. The associations between the physical home environment, socioeconomic status and moderate-to-vigorous physical activity, sedentary time and screen time were examined for 427 children, using analysis of covariance, and linear and logistic regression, with adjustment for gender and family structure.

RESULTS

The presence of TVs (p < 0.01) and video game consoles (p < 0.01) in children's bedrooms, and child possession of handheld video games (p = 0.04), cell phones (p < 0.01) and music devices (p = 0.04) was significantly and positively associated with screen time. Ownership of these devices (with the exception of music devices) was inversely related to socioeconomic status (parental education). Children's moderate-to-vigorous intensity physical activity (p = 0.04) and possession of active play equipment (p = 0.04) were both positively associated with socioeconomic status (household income), but were not related to each other (with the exception of bicycle ownership).

CONCLUSIONS

Children with less electronic devices, particularly in their bedrooms, participated in less screen time, regardless of socioeconomic status. Socioeconomic disparities were identified in children's moderate-to-vigorous physical activity, however socioeconomic status was inconsistently related to possession of active play equipment. Home active play equipment was therefore not a clear contributor to the socioeconomic gradients in Australian children's moderate-to-vigorous physical activity.

Development of sedentary behavior across childhood and adolescence: longitudinal analysis of the Gateshead Millennium Study

Background

In many parts of the world policy and research interventions to modify sedentary behavior of children and adolescents are now being developed. However, the evidence to inform these interventions (e.g. how sedentary behavior changes across childhood and adolescence) is limited. This study aimed to assess longitudinal changes in sedentary behavior, and examine the degree of tracking of sedentary behavior from age 7y to 15y.

Methods

Participants were part of the Gateshead Millennium Study cohort. Measures were made at age 7y (n = 507), 9y (n = 510), 12y (n = 425) and 15y (n = 310). Participants were asked to wear an ActiGraph GT1M and accelerometer epochs were defined as sedentary when recorded counts were ≤25 counts/15 s. Differences in sedentary time and sedentary fragmentation were examined using the Friedman test. Tracking was examined using Spearman’s correlation coefficients and trajectories over time were assessed using multilevel linear spline modelling.

Results

Median daily sedentary time increased from 51.3 % of waking hours at 7y to 74.2 % at 15y. Sedentary fragmentation decreased from 7y to 15y. The median number of breaks/hour decreased from 8.6 to 4.1 breaks/hour and the median bout duration at 50 % of the cumulative sedentary time increased from 2.4 min to 6.4 min from 7y to 15y. Tracking of sedentary time and sedentary fragmentation was moderate from 7y to 15y however, the rate of change differed with the steepest increases/decreases seen between 9y and 12y.

Conclusion

In this study, sedentary time was high and increased to almost 75 % of waking hours at 15y. Sedentary behavior became substantially less fragmented as children grew older. The largest changes in sedentary time and sedentary fragmentation occurred between 9y to 12y, a period which spans the transition to secondary school. These results can be used to inform future interventions aiming to change sedentary behavior.

Correlates of sedentary behaviour in 8- to 10-year-old children at elevated risk for obesity

The purpose of this study was to describe correlates of sedentary behaviour (SED) in children at elevated risk of obesity because of parental obesity. Participants were 534 children aged 8-10 years with ≥ 1 obese parent. SED and physical activity (PA) were measured by accelerometer, screen time by self-report, and height, weight, waist circumference, and cardiovascular fitness objectively measured. Data describing the child, parents, friends, and home and neighbourhood environments were from child self-report. Higher total SED time was significantly positively associated with child's age, mother's age, Tanner stage, weight status or waist circumference, less self-reported PA, choosing screen time over PA/sport, mother saying PA/sport good for them, and fewer weekly physical education (PE) classes. Exceeding 2 h/day screen time was significantly associated with child's age, male sex, weight status or waist circumference, choosing screen time over PA/sport, and dinnertime TV viewing. Children regularly watching TV with dinner had 2.3 times greater odds (95% confidence interval (CI) 1.52, 3.58) of exceeding screen time guidelines compared with children rarely watching TV with dinner; children reporting ≤ 2 PE classes/week had 2.4 times greater odds (95% CI 1.41, 4.10) of being in the highest SED tertile compared with children reporting >2 PE classes/week. Hence, the most sedentary children are older, more biologically mature, less active, more overweight/obese, have fewer PE classes, and are more likely to choose screen time over PA and watch TV with dinner compared with less sedentary children. PE opportunities and mealtime TV viewing are potentially modifiable targets for reducing total SED and screen time in children.

Seasonal Variation in Children's Physical Activity and Sedentary Time

PURPOSE

Understanding seasonal variation in physical activity is important for informing public health surveillance and intervention design. The aim of the current study was to describe seasonal variation in children's objectively measured physical activity and sedentary time.

METHODS

Data are from the UK Millennium Cohort Study. Participants were invited to wear an accelerometer for 7 d on five occasions between November 2008 and January 2010. Outcome variables were sedentary time (<100 counts per minute, min·d(-1)) and moderate to vigorous physical activity (MVPA) (>2241 counts per minute, min·d(-1)). The season was characterized using a categorical variable (spring, summer, autumn, or winter) and a continuous function of day of the year. Cross-classified linear regression models were used to estimate the association of each of these constructs with the outcome variables. Modification of the seasonal variation by sex, weight status, urban/rural location, parental income, and day of the week (weekday/weekend) was examined using interaction terms in regression models.

RESULTS

At least one wave of valid accelerometer data was obtained from 704 participants (47% male; baseline age, 7.6 (0.3) yr). MVPA was lower in autumn and winter relative to spring, with the magnitude of this difference varying by weekday/weekend, sex, weight status, urban/rural location, and family income (P for interaction <0.05 in all cases). Total sedentary time was greater in autumn and winter compared with spring; the seasonal effect was stronger during the weekend than during the weekday (P for interaction <0.01).

CONCLUSIONS

Lower levels of MVPA and elevated sedentary time support the implementation of intervention programs during autumn and winter. Evidence of greater seasonal variation in weekend behavior and among certain sociodemographic subgroups highlights targets for tailored intervention programs.

Determinants of changes in sedentary time and breaks in sedentary time among 9 and 12 year old children

The current study aimed to identify the determinants of objectively measured changes in sedentary time and sedentary fragmentation from age 9- to age 12 years. Data were collected as part of the Gateshead Millennium Birth Cohort study from September 2008 to August 2009 and from January 2012 to November 2012. Participants were 9.3 (± 0.4) years at baseline (n = 508) and 12.5 (± 0.3) years at follow-up (n = 427). Sedentary behaviour was measured using an ActiGraph GT1M accelerometer. Twenty potential determinants were measured, within a socio-ecological model, and tested for their association with changes in sedentary time and the extent to which sedentary behaviour is prolonged or interrupted (fragmentation index). Univariate and multivariate linear regression analyses were conducted. Measurements taken during winter and a greater decrease in moderate-to-vigorous intensity physical activity (MVPA) over time were associated with larger increases in sedentary time (seasonality β: - 3.03; 95% CI: - 4.52, - 1.54; and change in MVPA β: - 1.68; 95% CI: - 1.94, - 1.41). Attendance at sport clubs was associated with smaller increases in sedentary time (- 1.99; - 3.44, - 0.54). Girls showed larger decreases in fragmentation index (- 0.52; - 1.01, - 0.02). Interventions aimed at decreasing the decline in MVPA and increasing/maintaining sport club attendance may prevent the rise in sedentary time as children grow older. In addition, winter could be targeted to prevent an increase in sedentary time and reduction in sedentary fragmentation during this season.

Mediated Effects of Perceived Competence on Youth Physical Activity and Sedentary Behavior

PURPOSE

This study evaluates whether physical activity (PA) and sedentary behavior (SB) are influenced by a common mediating relationship.

METHOD

A total of 1,552 participants in 3rd to 12th grade completed an online survey that included assessments of PA at school (PAS), PA at home (PAH), and SB as well as a battery of psychosocial variables (i.e., attraction to PA and perceived competence).

RESULTS

Perceived competence had a direct positive effect on PA and a negative effect on SB. These associations were consistently (but partially) mediated by attraction to PA; however, the indirect effect (IE) of perceived competence was stronger for PAH (IE = .27, p < .05) than for PAS (IE = .07, p < .05), or SB (IE = .13, p < .05).

CONCLUSIONS

This study revealed some direct effects and IEs of perceived competence on PAS, PAH, and SB through attraction to PA as the mediator. PA and SB may be influenced by some common underlying psychosocial mediators.

Short-term Effects of a Physical Activity Intervention on Obesity and Cardiovascular Fitness of 12-14-year-old Boy Students

BACKGROUND

Some local governments have implemented strategies to increase physical activity as a way to control obesity in children, but in Iranian students few studies have evaluated the effects of such interventions on overweight and obese children. The aim of this study was to evaluate the effects of a short-term school-based physical activity on obesity and cardiovascular fitness in 12-14-year-old boy students.

METHODS

This study showed an intervention effect on some health-related fitness factors in students. A number of 127 boy students aged 12-14 years, in the city of Isfahan, based on preventive plan of inactivity in children at the provincial Health office selected randomly as subjects. Measurement variables include; weight, height, body mass index (BMI), waist-hip ratio (WHR), body-fat percent and aerobic power of subjects measured by valid tests.

RESULTS

This study revealed that body-fat percentage of this students changed near to 17.84% (42.25% pretest vs. 34.71% posttest), WHR 0.44%, (0.915 pretest vs. 0.911 posttest), VO2 max changed 8.54% (27.84 pretest vs. 30.22 posttest) whereas BMI was changed 2.61% (26.81 pretest vs. 26.03 posttest). Results also revealed that there were significant differences between fat percent, (P = 0.001) and VO2 max (P = 0.001), but there was no difference between BMI of subjects in pre and posttests (P = 0.452).

CONCLUSIONS

Findings of this study signify that an implementation of short-term intervention components in the school system may have a beneficial effect on body-fat percentage and cardiovascular fitness of overweight/obese children.

Correlation between Aerobic Fitness and Body Composition in Middle School Students

Background:

Since correlations have been found between body composition and physical activity in different parts of the world, inactivity and poor physical condition likely contributes main factors in childhood obesity. This study was implemented to determine the relationship between cardiovascular fitness and body-composition in a group of Iranian middle school students.

Methods:

In this descriptive study, subjects comprised of 12,946 students (10,531 girls and 2,415 boys aged 11–13 years) in the city of Isfahan. Height, weight, body-fat percent, body mass index, and cardiovascular fitness of the aforesaid students were measured by valid tests.

Results:

This study showed that fat percentage and aerobic fitness (VO₂ max) of girls were 24.73%, and 29.5 (ml/kg/min) and boys19.32% and 36.4 (ml/kg/min) respectively. Results also revealed that there was a negative significant correlation between fat percent and aerobic fitness of boys (r = −0.81), and girls (r = −0.77) respectively.

Conclusions:

To conclude, this study signifies that fat percentage augmentation leads to a decrease in aerobic fitness of children. Thus, fat percentage can be associated with different chronic diseases such as cardiovascular ones.

Short-term Effects of a Physical Activity Intervention on Obesity and Aerobic Fitness of Adolescent Girls

Background:

In the past two decades, physical activity has decreased during both childhood and adolescence, and particularly adolescence. It seems that schools are attractive settings in which to implement interventions designed in order to promote physical activity in children; but in Iranian students, few studies have evaluated the effects of such interventions on overweight and obese children. The aim of this study was to evaluate the effects of a short-term school-based physical activity on obesity and aerobic fitness in 12–14 years aged girls.

Methods:

This is a study with single group pretest and posttest design, in which 129 middle school girls in city of Isfahan were assessed based on preventive plan of inactivity in children at the Provincial Health Office. Variables, including weight, height, body mass index (BMI), waist-hip ratio (WHR), body fat percentage and aerobic power of subjects were measured using valid tests.

Results:

This study showed that subjects’ body fat percentage changed about 3.6% (37.74% pretest vs. 36.39% posttest), VO₂ max changed 7.43% (29.72 pretest vs. 31.93 posttest), WHR changed 1.12% (0.89 pretest vs. 0.88 posttest), whereas BMI was changed 1.65% (27.80 pretest vs. 27.34 posttest). Findings also revealed that there were significant differences between fat percent, (P = 0.001) and VO₂ max (P = 0.001) of subjects, but there was no difference between BMI of them in pre- and post-tests (P = 0.361).

Conclusions:

These results suggest that even a short-term exercise intervention may lead to positive changes in body fat percentage, WHR and aerobic fitness of overweight children. Therefore, school-based physical activity interventions can be an effective preventive strategy to control obesity and overweight in students.

Prevalence of Obesity and Overweight in 12-14-year-old Students in Isfahan-Iran

Background:

Childhood obesity is a worldwide major public health problem in both developed and developing countries. The purpose of this study was to determine the prevalence of obesity and overweight in 12-14-year-old students in the city of Isfahan.

Methods:

This study was conducted among 10,531 girls and 2415 boys aged 12–14 years in the city of Isfahan. Percentage of children in the corresponding body mass index (BMI) categories for overweight and obesity (specified by the Centers for Disease Control and Prevention criteria percentiles) were assessed, based on preventive plan of inactivity in children and youth of Isfahan province.

Results:

Findings revealed that prevalence of overweight in children varied by age from 15.3% to 26.9% in boys and 12.9% to 29.9% in girls, and prevalence of obesity varied from 14.8% to 33.7% and 15% to 29.9% in boys and girls, respectively. Percentile norms for BMI of subjects were computed based on sex categories.

Conclusions:

To conclude, results of the study revealed that subjects have approximately the same percentage of overweight/obesity compared to other children have been studied; however, in comparison to previous studies, a higher rate was witnessed in grade 8 boy students. These situations indicate that there are needs to implement some intervention programs, as well as management policies.

Active play opportunities at child care

BACKGROUND AND OBJECTIVES

Physical activity (PA) is important for children's health and development, yet preschoolers are not meeting PA recommendations. The objective of this study was to examine different PA opportunities at child care and how variation in indoor versus outdoor and free versus teacher-led opportunities relate to children's PA.

METHODS

An observational study of 98 children (mean age 4.5 years, 49% girls) from 10 child care centers. Classrooms were observed for at least 4 full days per center (total 50 days) to categorize time into (1) not an active play opportunity (APO); (2) naptime; (3) APO, outdoor free play; (4) APO, outdoor teacher-led; (5) APO, indoor free play; and (6) APO, indoor teacher-led. Children wore accelerometers during observations. Linear regression models examined the influence of APO categories on moderate-vigorous physical activity (MVPA) and sedentary time.

RESULTS

Children's activity was 73% sedentary, 13% light, and 14% MVPA. For 88% of time children did not have APOs, including 26% time as naptime. On average, 48 minutes per day were APOs (41% sedentary, 18% light, and 41% MVPA), 33 minutes per day were outdoors. The most frequent APO was outdoor free play (8% of time); outdoor teacher-led time was <1%. Children were more active and less sedentary outdoors versus indoors and during the child-initiated APOs (indoors and outdoors) versus teacher-led APOs.

CONCLUSIONS

Preschoolers were presented with significantly fewer than recommended opportunities for PA at child care. More APOs are needed for children to meet recommendations, particularly those that encourage more outdoor time, more teacher-led and child-initiated active play, and flexibility in naptime for preschoolers.

Adolescents' Sedentary Behaviors in Two European Cities

PURPOSE

The aim of this study was to determine and compare the correlates of objective sedentary behavior (SB) and nonschool self-reported SB in adolescents from 2 midsized cities, 1 in France (Tarbes) and 1 in Spain (Huesca). Stability of objective SB and nonschool self-reported SB were also assessed at different time points during 1 academic year.

METHOD

Starting with a total of 829 participants and after applying inclusion criteria, objective SB was assessed for 646 adolescents (Mage = 14.30 ± 0.71 years) with GT3X accelerometers for 7 days at 2 time points. Nonschool self-reported SB was measured for 781 adolescents (Mage = 14.46 ± 0.76 years) at 3 time points by means of a questionnaire. Data were analyzed using multiple regression analysis.

RESULTS

Gender and ambient temperature emerged as the main statistically significant correlates in all objective SB models, showing higher objective SB levels in girls and lower objective SB levels when ambient temperature was higher. According to nonschool self-reported SB, a gender effect was found in almost all behaviors. Whereas boys spent more time playing with video games as well as games on their mobile phones, girls spent more time studying and using their computers and mobile phones to communicate with each other. The findings showed a statistically significant city effect on study time (Huesca > Tarbes) and video games and telephone communication time (Tarbes > Huesca).

CONCLUSION

Nonschool self-reported SB patterns were different in Huesca and Tarbes. Intervention programs should be adapted to target the reduction of adolescents' SB according to different contexts.