Acculturation and its effects on the nutrition and physical activity of African migrant children

Studies the nutritional status, food intake, physical activity and acculturation in African migrant children living in Melbourne. Higher than expected overweight/obesity prevalence, and malnutrition, especially wasting, was observed in the study population. These children had high energy and macronutrient intake; compensated by high physical activity level. There was a strong positive association between acculturation and obesity.

Socioeconomic position and the tracking of physical activity and cardiorespiratory fitness from childhood to adulthood

This study examined the influence of childhood socioeconomic position (SEP) and social mobility on activity and fitness tracking from childhood into adulthood. In a prospective cohort of 2,185 Australian adults (aged 26–36 years), first examined in 1985 (at ages 7–15 years), self-reported physical activity and cardiorespiratory fitness (subsample only) were measured. SEP measures included retrospectively reported parental education (baseline) and own education (follow-up). There was little evidence of a relation between childhood SEP and activity tracking, but high childhood SEP (maternal education) was associated with a 59% increased likelihood of persistent fitness, and medium childhood SEP (paternal and parental education) was associated with a 33%–36% decreased likelihood of persistent fitness. Upward social mobility was associated with a greater likelihood of increasing activity (38%–49%) and fitness (90%), and persistently high SEP was associated with a greater likelihood of increasing activity (males: 58%) and fitness (males and females combined: 89%). In conclusion, persistently high SEP and upward social mobility were associated with increases in activity and fitness from childhood to adulthood. Findings highlight socioeconomic differentials in activity and fitness patterns and suggest that improvements in education may represent a pathway through which physical activity levels can be increased and health benefits achieved

Twelve-month effects of a playground intervention on children's morning and lunchtime recess physical activity levels

Background: Recess is an opportunity for children to engage in daily physical activity. The aim of this study was to investigate the 12-month effects of a playground intervention on children’s moderate-to-vigorous (MVPA) and vigorous physical activity (VPA) during morning and lunchtime recess.

Methods: Four hundred and seventy children (232 boys, 238 girls) from 26 elementary schools participated in the study. Fifteen schools redesigned the playground environment using playground markings and physical structures. Eleven schools served as socioeconomic matched controls. Physical activity levels were quantified using heart rate and accelerometry at baseline, 6 months, and 12 months post-intervention. A 3-level (time, pupil, and school) multilevel analysis was used to determine the effects of the intervention across time on MVPA and VPA.

Results: Positive yet nonsignificant intervention effects were found for MVPA and VPA during morning and lunchtime recess. Intervention children were more active during recess than control children. Interactions revealed that the intervention effect was stronger at 6 months than 12 months post-intervention.

Conclusions: A playground markings and physical structures intervention had a positive effect on intervention children’s morning and lunchtime MVPA and VPA when assessed using heart rate and accelerometry, but this effect is strongest 6-months post-intervention and decreased between 6 months and 12 months.

Relationships between maturity status, physical activity and physical self-perceptions in primary school children

The aim of this study was to examine the influence of maturity status on primary school children's physical activity and physical self-perceptions. Altogether, 175 children (97 girls, 78 boys) aged 10.6 ± 0.3 years completed the Children and Youth Physical Self-Perception Profile and wore an ActiGraph accelerometer for five consecutive days to assess moderate-to-vigorous physical activity. Anthropometric measures were completed to estimate maturity status. A two-level, multi-level analysis was used to assess the influence of maturity status on moderate-to-vigorous physical activity and physical self-perceptions. Boys performed more moderate-to-vigorous physical activity than girls (P < 0.0001), but when the effect of maturity status was controlled the difference was reduced (P = 0.02). Significant differences between the sexes were also observed for physical self-perception sub-domains (boys > girls, P = 0.02 to 0.0001). When maturity status was added to the model, significant differences were no longer apparent for each sub-domain, with the exception of perceived strength. Significant interactions between gender and maturity status revealed that boys' physical self-perceptions improved with more advanced maturity status, whereas girls' self-perceptions decreased (P = 0.07 to 0.002). Significant differences between the sexes in moderate-to-vigorous physical activity and some domains of physical self-perceptions were reduced or no longer evident when the effect of maturity status was controlled. Maturity status may differentially influence boys' and girls' physical self-perceptions.

Children's physical activity levels during school recess : a quasi-experimental intervention study

Background : Recess provides a daily opportunity for children to engage in moderate-to-vigorous (MVPA) and vigorous physical activity (VPA). Limited research has investigated the effects of recess-based interventions on physical activity using large sample sizes whilst investigating variables that may influence the intervention effect. The aim of the study was to investigate the short-term effects of a playground markings and physical structures intervention on recess physical activity. A secondary aim was to investigate the effects of covariates on the intervention.

Methods : 150 boys and 147 girls were randomly selected from 26 elementary schools to wear uni-axial accelerometers that quantified physical activity every 5 seconds during recess. Fifteen schools located in deprived areas in one large urban city in England received funding through a national initiative to redesign the playground environment. Eleven schools served as matched socioeconomic controls. Data were collected at baseline and 6-weeks following playground intervention. Recess MVPA and VPA levels adjusted for pupil- and school-level covariates (baseline physical activity, age, gender, recess length, body mass index) were analysed using multilevel analyses.

Results : Positive but non-significant intervention effects were found for MVPA and VPA when confounding variables were added to the model. Gender was a significant predictor of recess physical activity, with boys engaging in more MVPA and VPA than girls. Significant interactions for MVPA revealed that the intervention effect was stronger for younger elementary aged school children compared to older children, and the intervention effect increased as daily recess duration increased.

Conclusion : The playground redesign intervention resulted in small but non-significant increases in children's recess physical activity when school and pupil level variables were added to the analyses. Changing the playground environment produced a stronger intervention effect for younger children, and longer daily recess duration enabled children to engage in more MVPA following the intervention. This study concludes that the process of increasing recess physical activity is complex when school and pupil-level covariates are considered, though they should be taken into account when investigating the effects of playground intervention studies on children's physical activity during recess.

Physical activity levels of children during school playtime

School represents a suitable setting for intervention programmes aiming to promote physical activity to benefit health. During the school day, physical education and school playtime offer children regular opportunities to engage in physical activity. However, there is growing concern that, internationally, curricular time allocated to physical education is not meeting statutory guidelines. The effectiveness of the playground environment to promote physical activity has been considered as a complementary setting to physical education.

Physical activity guidelines state that children should engage in at least 1 hour of moderate intensity physical activity a day. Currently no empirically tested guidelines exist for physical activity levels during playtime. However, studies cited in this article indicate that playtime can contribute between 5-40% of recommended daily physical activity levels when no interventions have been utilised.

The limited school-based investigations that have been reported in the literature suggest that boys engage in more physical activity during playtime than girls. Studies that have implemented intervention strategies in order to promote physical activity levels indicate that playtime can substantially contribute towards daily optimal physical activity guidelines. Energy expenditure and physical activity levels have increased during playtime following the implementation of playtimebased interventions. In order to advance knowledge of children's physical activity during playtime, a number of key issues for consideration in future research are detailed. Research on children's use of playtime to be physically active and the extent of the contribution of playtime to daily physical activity guidelines is warranted.

The longitudinal influence of home and neighbourhood environments on children's body mass index and physical activity over 5 years : the CLAN study

Objective: To determine the independent contributions of family and neighbourhood environments to changes in youth physical activity and body mass index (BMI) z-score over 5 years.

Methods: In 2001, 2004 and 2006, 301 children (10–12 years at baseline) had their height and weight measured (BMI was converted to z-scores using Centers for Disease Control and Prevention reference charts; see http://www.cdc.gov/growthcharts) and moderate-to-vigorous physical activity (MVPA) assessed using accelerometers. In 2001, parents reported on the home environment (social support, role modelling, rules and restrictions, physical environment) and perceived neighbourhood environment (local traffic, road safety, sporting venues, public transport), and Geographic Information Systems were used to map features of the neighbourhood environment (destinations, road connectivity, traffic exposure). Generalized estimating equations were used to predict average BMI z-score and MVPA over time from baseline home and perceived and objective neighbourhood environment factors.

Results: Among boys, maternal education and heavy traffic were inversely associated, and sibling physical activity, maternal role modelling of MVPA and the presence of dead-end roads were positively associated with MVPA. Having unmarried parents, maternal MVPA role modelling and number of home sedentary items were positively associated with BMI z-score among boys. Among girls, having siblings, paternal MVPA role modelling, physical activity rules and parental physical activity co-participation were positively associated with MVPA. Having unmarried parents and maternal sedentary behaviour role modelling were positively associated, and number of sedentary behaviour rules and physical activity items were inversely associated with BMI z-score among girls.

Conclusion: The home environment seems more important than the neighbourhood environment in influencing children's physical activity and BMI z-score over 5 years. Physical activity and weight gain programmes among youth should focus on parental role modelling, rules around sedentary and active pursuits, and parental support for physical activity. Intervention studies to investigate these strategies are warranted.

Dog ownership, dog walking and children's and parents' physical activity

This study aimed to determine cross-sectional associations of dog ownership, dog walking, and physical activity (PA) among children and their parents. Objective measures of PA were obtained for children ages 5-6 and 10-12 years from 19 primary schools across Melbourne, Australia. Parents self-reported their PA, dog ownership, and frequency of dog walking: 53% of families owned a dog, 41% of children who owned a dog did not walk their dog at all, and 32% reported never or rarely walking their dog as a family. Dog ownership was associated with an additional 29 min/day in PA among younger girls, and 70 and 59 min/week more in PA among mothers of younger boys and older girls, respectively. Among mothers of older girls, dog owners were 1.6 times as likely to meet PA guidelines. Mothers with older boys and girls, and fathers with younger boys, who reported walking the dog regularly as a family, spent more time in PA (105, 90, and 158 more min/week, respectively). Promoting dog ownership and dog walking among children and as a family are potential strategies for increasing PA participation in some families.

Love thy neighbour? Associations of social capital and crime with physical activity amongst women

Using a multilevel study design, this study examined the associations between social characteristics of individuals and neighbourhoods and physical activity among women. Women (n = 1405) recruited from 45 Melbourne (Australia) neighbourhoods of varying socioeconomic disadvantage provided data on social factors and leisure-time: physical activity; walking; and walking in one’s own neighbourhood. Individual level social factors were number of neighbours known and social participation. Neighbourhood-level social characteristics (interpersonal trust, norms of reciprocity, social cohesion) were derived by aggregating survey data on these constructs within neighbourhoods. Objective data on crimes within neighbourhoods were obtained from Victoria Police. In bivariable regression models, all social variables at both the individual and neighbourhood level were positively associated with odds of physical activity, walking, and walking in one’s own neighbourhood. Associations with individual social participation (associated with all three physical activity variables) and neighbourhood interpersonal trust (associated with overall physical activity only) remained significant in multivariable models. Neither neighbourhood crime against the person nor incivilities were associated with any form of physical activity. These results demonstrate that women who participated in local groups or events and, less consistently, women living in neighbourhoods where residents trusted one another, were more likely to participate in leisure-time physical activity. While redressing macro-level social and economic policies that contribute to neighbourhood inequalities remains a priority, public health initiatives aimed at promoting physical activity could consider focusing on fostering social interactions targeting both individuals and communities. Further investigation of causal mechanisms underlying these associations is required.

Effects of a daily school based physical activity intervention program on muscle development in prepubertal girls

This 12-month prospective controlled intervention evaluated the effect of a general school based physical activity program on muscle strength, physical performance and body composition in prepubertal girls. Fifty-three girls aged 7–9 years involved in a school based exercise program [40 min/day of general physical activity per school day (200 min/week)] were compared with 50 age-matched girls who participated in the general Swedish physical education curriculum (mean 60 min/week). Body composition (DXA), isokinetic peak torque (PT) of the knee extensors and flexors at 60 and 180°/s, and vertical jump height (VJH) were assessed at baseline and 12 months. The annual gain in weight was similar between the groups, but there was a greater increase in total body and regional lean mass (P < 0.05) and fat mass (P < 0.01) in the exercise group. Mean gains in knee extensor PT at 60 and 180°/s were 7.0–7.6% greater in the exercise group (P ranging <0.05–<0.001). No significant differences were detected in VJH. In conclusion, increasing school based physical education to at least 3 h/week provides a feasible strategy to enhance the development of muscle strength and lean mass in prepubertal girls.

Policy change to create supportive environments for physical activity and healthy eating : which options are the most realistic for local government?

The objective is to identify and test regulatory options for creating supportive environments for physical activity and healthy eating among local governments in Victoria, Australia. A literature review identified nine potential areas for policy intervention at local government level, including the walking environment and food policy. Discussion documents were drafted which summarized the public health evidence and legal framework for change in each area. Levels of support for particular interventions were identified through semi-structured interviews conducted with key informants from local government. We conducted 11 key informant interviews and found support for policy intervention to create environments supportive of physical activity but little support for policy changes to promote healthy eating. Participants reported lack of relevance and competing priorities as reasons for not supporting particular interventions. Promoting healthy eating environments was not considered a priority for local government above food safety. There is a real opportunity for action to prevent obesity at local government level (e.g. mandate the promotion of healthy eating environments). For local government to have a role in the promotion of healthy food environments, regulatory change and suitable funding are required.

A review of population-based prevalence studies of physical activity in adults in the Asia-Pacific region

Background: Physical activity (PA) surveillance is an important component of non-communicable disease risk factor monitoring, and occurs through national and international surveillance systems. This review identifies population PA estimates for adults in the Asia-Pacific region, and examines variation in trends and prevalence rates obtained using different PA measures.

Methods: Data were obtained from a MEDLINE search; World Health Organization’s Global Health Infobase; Government websites and reference lists of relevant papers. Inclusion criteria included: national studies or those reporting large scale population-level data; data published from 2000 to 2010 and trend data prior; sample sizes over n = 1000, or fewer subjects in small nations.

Results: In total, 56 population surveys from 29 Asia-Pacific countries were identified. Data on ‘sufficient physical activity’ amongst adults were available from 45 studies (80%), with estimates ranging from 7% to 93% (median 62%, inter-quartile range 40%-85%). For 14 countries, estimates of ‘sufficient activity’ were documented in multiple surveys using different methods, with the largest variation from 18% to 92% in Nepal. Median or mean METminutes/ day, reported in 20 studies, ranged from 6 to 1356. Serial trend data were available for 11 countries (22%), for periods spanning 2-10 years. Of these, five countries demonstrated increases in physical activity over time, four demonstrated decreases and three showed no changes.

Conclusions: Many countries in the Asia-Pacific region collect population-level PA data. This review highlights differences in estimates within and between countries. Some differences may be real, others due to variation in the PA questions asked and survey methods used. Use of standardized protocols and measures, and combined reporting of data are essential goals of improved international PA surveillance.

A cross-sectional study of the individual, social, and built environmental correlates of pedometer based physical activity among elementary school children

Background: Children who participate in regular physical activity obtain health benefits. Preliminary pedometerbased cut-points representing sufficient levels of physical activity among youth have been established; however limited evidence regarding correlates of achieving these cut-points exists. The purpose of this study was to identify correlates of pedometer-based cut-points among elementary school-aged children.
Method: A cross-section of children in grades 5-7 (10-12 years of age) were randomly selected from the most (n = 13) and least (n = 12) ‘walkable’ public elementary schools (Perth, Western Australia), stratified by socioeconomic status. Children (n = 1480; response rate = 56.6%) and parents (n = 1332; response rate = 88.8%) completed a survey, and steps were collected from children using pedometers. Pedometer data were categorized to reflect the sex-specific pedometer-based cut-points of ≥15000 steps/day for boys and ≥12000 steps/day for girls. Associations between socio-demographic characteristics, sedentary and active leisure-time behavior, independent mobility, active transportation and built environmental variables - collected from the child and parent surveys - and meeting pedometer-based cut-points were estimated (odds ratios: OR) using generalized estimating equations.
Results: Overall 927 children participated in all components of the study and provided complete data. On average, children took 11407 ± 3136 steps/day (boys: 12270 ± 3350 vs. girls: 10681 ± 2745 steps/day; p < 0.001) and 25.9% (boys: 19.1 vs. girls: 31.6%; p < 0.001) achieved the pedometer-based cut-points. After adjusting for all other variables and school clustering, meeting the pedometer-based cut-points was negatively associated (p < 0.05) with being male (OR = 0.42), parent self-reported number of different destinations in the neighborhood (OR 0.93), and a friend’s (OR 0.62) or relative’s (OR 0.44, boys only) house being at least a 10-minute walk from home. Achieving the pedometer-based cut-points was positively associated with participating in screen-time < 2 hours/day (OR 1.88), not being driven to school (OR 1.48), attending a school located in a high SES neighborhood (OR 1.33), the average number of steps among children within the respondent’s grade (for each 500 step/day increase: OR 1.29), and living further than a 10-minute walk from a relative’s house (OR 1.69, girls only).
Conclusions: Comprehensive multi-level interventions that reduce screen-time, encourage active travel to/from school and foster a physically active classroom culture might encourage more physical activity among children.

School day segmented physical activity patterns of high and low active children

Background

Variability exists in children's activity patterns due to the association with environmental, social, demographic, and inter-individual factors. This study described accelerometer assessed physical activity patterns of high and low active children during segmented school week days whilst controlling for potential correlates.
Methods

Two hundred and twenty-three children (mean age: 10.7 +/- 0.3 yrs, 55.6% girls, 18.9% overweight/obese) from 8 north-west England primary schools wore ActiGraph GT1M accelerometers for 7 consecutive days during autumn of 2009. ActiGraph counts were converted to minutes of moderate (MPA), vigorous (VPA) and moderate-to-vigorous (MVPA) physical activity. Children were classified as high active (HIGH) or low active (LOW) depending on the percentage of week days they accumulated at least 60 minutes of MVPA. Minutes spent in MPA and VPA were calculated for school time and non-school time and for five discrete school day segments (before-school, class time, recess, lunchtime, and after-school). Data were analysed using multi-level modelling.
Results

The HIGH group spent significantly longer in MPA and/or VPA before-school, during class time, lunchtime, and after-school (P < .05), independent of child and school level factors. The greatest differences occurred after-school (MPA = 5.5 minutes, VPA = 3.8 minutes, P < 0.001). MPA and VPA were also associated with gender, BMI z-score, number of enrolled children, playground area per student, and temperature, depending on the segment analysed. The additive effect of the segment differences was that the HIGH group accumulated 12.5 minutes per day more MVPA than the LOW group.
Conclusions

HIGH active children achieved significantly more MPA and VPA than LOW active during four of the five segments of the school day when analyses were adjusted for potential correlates. Physical activity promotion strategies targeting low active children during discretionary physical activity segments of the day, and particularly via structured after-school physical activity programs may be beneficial.