Environmental influences on children's physical activity

Impaired vision and physical activity in childhood and adolescence: findings from the Millennium Cohort Study

BACKGROUND/AIMS

Investigate if impaired vision is associated with reduced levels and differences in types of physical activity (PA) to identify barriers or enablers to achieving healthy PA levels.

METHODS

Data from the Millennium Cohort Study of children born in the UK in 2000-2001 and followed-up to age 14 years (n=11 571). Using parental report on eye conditions coded by clinicians, children were categorised as having no, unilateral or bilateral impaired vision. Outcomes included objective accelerometer-derived time spent in moderate-to-vigorous physical activity (MVPA), and 16 PA types reported by parents, teachers and/or participants, covering physical education (PE), organised sports, self-organised sports and hobbies.

RESULTS

Overall, 50% of 7-year-olds and subsequently 41% as 14-year-olds achieved the internationally recommended level of ≥60 MVPA min/day, irrespective of vision status, and mainly attributable to PE and organised sports. Bilateral impaired vision (vs none) was associated with parent-reported difficulties with PE (adjusted OR, 4.67; 95% CI, 2.31 to 9.41), self-rated poor ability in PE (3.21; 1.44 to 7.15) and not enjoy indoor PA (0.48; 0.26 to 0.88). Unilateral impaired vision was associated with both parent-rated difficulties (1.80; 1.26 to 2.59) and teachers' perception of low ability in PE (2.27; 1.57 to 3.28), and reduced odds of high participation in organised sports (0.77; 0.59 to 0.99). Age-related trajectories showed suboptimal PA in childhood tracked into adolescence, with no difference by vision status.

CONCLUSION

Population-wide programmes to increase PA levels in children should pay special attention to those with impaired vision and include early interventions to encourage participation and confidence in PE and organised sports, starting in primary school and maintained afterwards.

Results from Brazil's 2022 Report Card on Physical Activity for Children and Adolescents

This research aims to summarize the process and results of the 2022 Report Card on Physical Activity for Brazilian children and adolescents. A group of experts led by 10 PhD researchers gathered the best possible evidence on physical activity indicators. The Report Card Brazil 2022 included the top 10 indicators of physical activity and sleep, obesity, and poor mental health variables, which made up four dimensions: (I) Daily Behaviors; (II) Settings and Sources of Influence; (III) Government Strategies and Investments; and (IV) Health Outcomes. Comprehensive searches, including peer-reviewed and gray literature searches, were performed for each indicator. Data were considered from systematic reviews, local and national surveys, websites, and official information from the Brazilian Federal Government. Grades from the indicators ranged from F (Active Play) to B (School). In addition, the results found for each indicator were Overall Physical Activity (D), Organized Sport Participation (C-), Active Transportation (C), Sedentary Behaviors (D), Sleep (C), Family and Peers (C-), Community and Environment (C), Government (D+), Physical Fitness (D+), Obesity (11.7%), and Poor Mental Health (37.8%). Successfully strategies for increasing physical activity among Brazilian children and adolescents should look at the different indicators presented in this report.

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 prevalence and correlates of physical activity/inactivity and sedentary behaviour among high-school adolescents in Iran: a cross-sectional study

Background

Physical inactivity and sedentary behaviour are the main risk factors for non-communicable diseases in all stages of life. However, there is a lack of reliable data regarding the recommended level of physical activity and its correlates related to physical inactivity and sedentary behaviour among school students in Iran. The aim of the present study was to report the prevalence and correlates of physical activity/inactivity and sedentary behaviour among Iranian high school adolescents.

Methods

The Global School-based Student Health Survey (GSHS) was used for data collection. Related data comprising socio-demographics, health risk behaviour and protective factors were obtained from 1517 high school students. Multivariate logistic regression was used to assess the association between relevant independent variables (e.g. gender) and the dependent outcome variable (physical inactivity/sedentary behaviour).

Results

The prevalence of recommended physical activity by WHO was 27.8%, physical inactivity 72.2% and sedentary behaviour 71.4%. Being female, being overweight or obese, walking/cycling to or from school on 1–4 days, sitting 3 or more hours/day (sedentary behaviour), insufficient vegetable intake, being bullied and lack of parental support, peer support and parental connectivity (protective factors) were positively associated with physical inactivity. On the other hand, walking/cycling to or from school on 5–7 days and inadequate fruit intake were negatively associated with physical inactivity. Walking/cycling to or from school on 1–4 days, being physically inactive, inadequate fruit intake and being bullied were positively associated with sedentary behaviour.

Conclusion

The prevalence of physical inactivity and sedentary behaviour was high in our studied sample. Interventions that address the issue of active school transport, sedentary behaviour, fruit and vegetable intake, family and peer support and bullying should be given more priority by the public health authorities.

Associations of active travel with adiposity among children and socioeconomic differentials: a longitudinal study

OBJECTIVES

Examine longitudinal associations between modes of travel to school and adiposity.

SETTING

The UK.

PARTICIPANTS

8432 children surveyed at ages 7, 11 and 14 years from the UK Millennium Cohort Study.

PRIMARY AND SECONDARY OUTCOMES

Objective percentage body fat and body mass index (BMI). Transport mode was categorised as private motorised transport, public transport and active transport (walking or cycling). Socioeconomic position (SEP) was measured by household income group and occupational social class. We adjusted analyses for changes in the country of UK, frequency of eating breakfast, self-reported growth spurts, hours of screen time and days per week of moderate-to-vigorous physical activity. Longitudinal (panel) regression models adjusting for individual fixed effects examined associations in changes in mode of travel to school and adiposity, controlling for both time-varying and time-invariant potential confounders. Interaction tests and stratified analyses investigated differences by markers of SEP.

RESULTS

At age 14 years, 26.1% of children (2198) reported using private motorised transport, 35.3% (2979) used public transport and 38.6% (3255) used active transport to get to school. 36.6% (3083) of children changed mode two times between the three waves and 50.7% (4279) changed once. Compared with continuing to use private transport, switching to active transport was associated with a lower BMI (-0.21 kg/m², 95% CI -0.31 to -0.10) and body fat (-0.55%, 95% CI -0.80% to -0.31%). Switching to public transport was associated with lower percentage body fat (-0.43%, 95% CI -0.75% to -0.12%), but associations with BMI did not reach statistical significance (-0.13 kg/m², 95% CI -0.26 to 0.01). Interaction tests showed a trend for these effects to be stronger in more deprived groups, but these interactions did not reach statistical significance.

CONCLUSION

This longitudinal study during a key life course period found switching to physically active forms of travel can have beneficial adiposity impacts; these associations may be more apparent for more disadvantaged children. Increasing active travel has potential to ameliorate inequalities.

Prevalence and socio-demographic correlates of accelerometer measured physical activity levels of school-going children in Kampala city, Uganda

Background

The current international physical activity guidelines for health recommend children to engage in at least 60 minutes of moderate-to-vigorous physical activity (MVPA) daily. Yet, accurate prevalence estimates of physical activity levels of children are unavailable in many African countries due to the dearth of accelerometer-measured physical activity data. The aim of this study was to describe the prevalence and examine the socio-demographic correlates of accelerometer-measured physical activity among school-going children in Kampala city, Uganda.

Methods

A cross-sectional study design was used to recruit a sample of 10–12 years old school-going children (n = 256) from 7 primary schools (3 public schools and 4 private schools) in Kampala city, Uganda. Sedentary time, light-intensity physical activity (LPA), moderate-intensity physical activity (MPA) and vigorous-intensity physical activity (VPA) were measured by accelerometers (ActiGraph GT3X+ [Pensacola, Florida, USA]) over a seven-day period. Socio-demographic factors were assessed by a parent/guardian questionnaire. Weight status was generated from objectively measured height and weight and computed as body mass index (BMI). Multi-level logistic regressions identified socio-demographic factors that were associated with meeting physical activity guidelines.

Results

Children’s sedentary time was 9.8±2.1 hours/day and MVPA was 56±25.7 minutes/day. Only 36.3% of the children (38.9% boys, 34.3% girls) met the physical activity guidelines. Boys, thin/normal weight and public school children had significantly higher mean daily MVPA levels. Socio-demographic factors associated with odds of meeting physical activity guidelines were younger age (OR = 0.68; 95% CI = 0.55–0.84), thin/normal weight status (OR = 4.08; 95% CI = 1.42–11.76), and socioeconomic status (SES) indicators such as lower maternal level of education (OR = 2.43; 95% CI = 1.84–3.21) and no family car (OR = 0.31; 95% CI = 0.17–0.55).

Conclusion

Children spent a substantial amount of time sedentary and in LPA and less time in MVPA. Few children met the physical activity guidelines. Lower weight status, lower maternal education level and no family car were associated with meeting physical activity guidelines. Effective interventions and policies to increase physical activity among school-going children in Kampala, are urgently needed.

Excessive Screen Media Use in Preschoolers Is Associated with Poor Motor Skills

Excessive screen media use exposure is a robust childhood predictor of sedentary behavior. The association between excessive exposure to sedentary behaviors (e.g., screen media use) and motor skills and how this association differs across sociodemographic strata is an important knowledge gap that needs to be addressed. The study aims to investigate the association of motor skills and screen media use in preschool children, taking into account sociodemographic variables, physical activity, and sleep profile. A cross-sectional survey of 926 children from 27 preschools was performed. The main outcome was defined as motor skills assessed using the general motor quotient (GMQ). Independent variables included sociodemographic variables, screen media use, screen habits, physical activity, and sleep duration. Logistic regression models were used to estimate the associations between the children's motor skills and each exposure factor. More than 55 percent of the children ate while watching television and 28 percent spent a long time watching television, playing video games, or using a computer, tablet, or cell phone. Excessive screen media use increased the risk of a low GMQ by 72 percent and inactivity in children increased the odds by 90 percent; sleep duration at night decreased the odds of a low GMQ by 51 percent and daytime sleep decreased the odds by 33 percent. Excessive screen media use has been associated with poor motor skills and increased physical inactivity in children, especially among those with prolonged exposure. Our findings can alert parents to the consequences of excessive screen media use and can motivate policymakers to encourage sports and other health-promotion strategies.

Parent recommendations to support physical activity for families with young children: Results of interviews in deprived and affluent communities in South Wales (United Kingdom)

BACKGROUND

Physical inactivity is the fourth leading cause of mortality worldwide. Early childhood is a critical period when healthy behaviours can be instilled for a future active lifestyle. We explored community, societal and environmental factors affecting child and family physical activity and sought parent recommendations to support physical activity in families with young children.

METHODS

We interviewed 61 parents expecting a child or with a baby ≤12 months (35 mother and father paired interviews and 26 interviews with mothers only). We purposively sampled families for neighbourhood deprivation status (Townsend Index; 26 affluent; 35 deprived). We conducted thematic analysis of interview transcripts using Bronfenbrenner's socio-ecological framework to guide interpretation.

RESULTS

We identified four themes: work family-life balance; spaces for activity; beliefs and attitudes; and physical activity facilitators. We found that parents from deprived neighbourhoods were more likely to be underactive because of a complex web of community, social and personal factors which reduced motivation and hindered opportunity for physical activity. To increase knowledge and opportunity, respondents suggested 'help not tell' messages covering 'why', 'how' and 'where' information about physical activity, and using physical activity to support community engagement and social interaction.

CONCLUSIONS

Recommendations from parents highlight effective communication about the importance of early child and family physical activity and improved community access to safe facilities and opportunities. Both parents need to be engaged in designing interventions to support greater physical activity and healthy behaviours which are relevant and achievable in individuals' lives.

What if all children achieved WHO recommendations on physical activity? Estimating the impact on socioeconomic inequalities in childhood overweight in the UK Millennium Cohort Study

Background

The World Health organization (WHO) recommends that children engage in 60 min daily moderate-to-vigorous physical activity (dMVPA). Just half of children in the UK achieve these levels (with similarly low levels in other high-income countries). Thus, the dMVPA target is a focus of national obesity strategies. However, the potential impact of increased physical activity on prevalence and inequalities in childhood overweight is unknown. Using objective data from the Millennium Cohort Study (∼18 000 children born 2000–02) we simulated a series of hypothetical physical activity intervention scenarios: achievement of the target, and more realistic increases demonstrated in trials.

Methods

Predicted probabilities of overweight and obesity (using measured heights and weights at age 11) were estimated in multinomial marginal structural models, adjusting for dMVPA (measured with accelerometers at age 7) and confounding. Inequalities were assessed according to household income quintiles [risk ratios (RRs) and risk differences (RDs)]. Intervention scenarios were simulated by re-estimating predicted probabilities of overweight/obesity after manipulating (increasing) dMVPA by varying amounts, for different eligibility criteria and with varying uptake. Analyses included 6493 children with accelerometer data. Survey weights and multiple imputation addressed sampling design, attrition and item missingness.

Results

In all, 27% children were overweight/obese, with relative and absolute inequalities in the expected direction; 51% children were achieving 60 min dMVPA, with those from the lowest income quintile achieving, on average, 3 min more dMVPA than those from the highest income quintile. A simulation of universal achievement of the dMVPA target reduced the prevalence of overweight/obesity to 22%, but increased relative inequalities (absolute inequalities were unchanged). Smaller increases in dMVPA (informed by intervention evidence) did little to reduce prevalence or inequalities, even when targeting high-risk groups.

Conclusions

Universal achievement of the WHO dMVPA target, if attainable, would reduce prevalence of childhood overweight and obesity but not inequalities. Scale-up of more realistic interventions would have limited impact.

Could Greater Physical Activity Reduce Population Prevalence and Socioeconomic Inequalities in Children's Mental Health Problems? A Policy Simulation

BACKGROUND

One in four children 5-16 years (y) of age shows signs of mental health problems in the United Kingdom; risk is higher in economically disadvantaged groups. Greater physical activity is associated with lower risk of internalizing problems such as depression and anxiety. We simulated the potential impact of population-wide physical activity interventions on overall prevalence of internalizing problems, and by family income. Interventions were based on the World Health Organization (WHO) children's target of 60 minutes (min) of moderate-to-vigorous physical activity per day and trial evidence.

METHODS

Data were from the UK Millennium Cohort Study, a population-representative cohort of children born in 2000-2002. Household income (5 y) was the exposure; internalizing problems (outcome) were measured using the Strengths and Difficulties Questionnaire (11 y). Of 18,296 singletons, 6,497 had accelerometer physical activity data (mediator, manipulated to simulate interventions) at 7 y. We predicted probabilities of outcome according to exposure in marginal structural models, weighted for attrition and confounding, and adjusted for observed mediator. We then re-estimated probabilities in different physical activity intervention scenarios, assessing income inequalities in internalizing problems with risk ratios (RRs) and differences (RDs) according to income quintile.

RESULTS

Simulating universal achievement of the WHO target led to little change in prevalence (10% [95% CI = 8%, 12%]) and socioeconomic inequalities in internalizing problems; RR: 2.2 (1.1, 3.4); RD: 8% [5%,13%]). More modest increases in physical activity achieved weaker results.

CONCLUSIONS

Our simulations suggest that large increases in moderate-to-vigorous physical activity in the United Kingdom would have little effect on prevalence and inequalities in child mental health problems.

Influence of individual and family factors on physical activity among Saudi girls: a cross-sectional study

BACKGROUND

Physical inactivity is a major public health problem and one of the main causes of noncommunicable diseases among children. The physical activity (PA) of children has been studied extensively in other countries, but not in Saudi Arabia, most especially among school-based girls.

OBJECTIVES

Assess the PA among older Saudi girls (10-15 years old) and determine the influence of various personal and family factors on PA.

DESIGN

Descriptive, cross-sectional study.

SETTING

Primary and middle schools in Riyadh, Saudi Arabia.

SUBJECTS AND METHODS

Using a multi-stage stratified sampling technique, school girls were surveyed using the Physical Activity Questionnaire for Older Children (PAQ-C). Personal and familial factors that influenced PA levels were assessed by multiple regression analysis.

MAIN OUTCOME MEASURES

PA levels of Saudi school girls.

SAMPLE SIZE

464 girls.

RESULTS

The mean (SD) score of the respondents in the PAQ-C was 2.63 (0.57, range=1.27-4.24). The majority of the older children re.ported a moderate level of PA in the last seven days (73.5%), whereas 22.4% and 4.1% of them reported low and high levels of PA, respectively. Employment status of the parents and monthly family income were significant factors that influenced the PA of children.

CONCLUSIONS

The findings reiterate the significance of improving the PA of school girls and the critical role of the family in improving chil.dren's PA. Multisectoral coordination between schools, health agencies, families, and other concerned agencies to plan and implement interventions should help increase the PA of school girls.

LIMITATIONS

The use of self-report may have introduced some levels of social desirability bias. The study was only conducted in a single city.

CONFLICT OF INTEREST

None.

Sibling influence on children's objectively measured physical activity: a meta-analysis and systematic review

Abstract

Children without siblings (only children) have higher rates of obesity than children with siblings. Childhood obesity may be prevented by minimising sedentary behaviour and accumulating sufficient physical activity in young children. A growing number of articles have examined the influence of siblings on physical activity and sedentary behaviour, yet these articles have not been synthesised.

Objective

To synthesise literature and describe the influence of siblings on objectively measured physical activity and sedentary behaviour of children (ages 2–18 years).

Design

Outcomes were analysed in a systematic review and meta-analysis.

Data sources

PubMed, EMBASE, Web of Science and Medline OVID were searched for articles related to siblings, physical activity, sedentary behaviour and obesity outcomes from 1947 to March 2018.

Eligibility criteria

Articles that evaluated sibling status on physical activity objectively measured by accelerometer or pedometer were included.

Results

Nineteen articles, representing 17 independent datasets, were included in the review. Nine were included in the quantitative analysis. Pooled data from nine articles indicated children with siblings had higher moderate-to-vigorous physical activity (MVPA) relative to only children, with a potential dose response for higher number of children in household and higher MVPA (Mean Difference=3.13, 95% CI 1.90 to 4.35, p=0.001). Findings were mixed for the influence of siblings on sedentary behaviour and light physical activity.

Summary/Conclusion

Children with siblings had healthier physical activity patterns, as measured by accelerometer or pedometer, than did only children. Suggested mechanisms include peer modelling, encouraging active transport and sports participation, opportunity for playmate and serving as additional caregivers.

Trial registration number

CRD42017055463.

Health-related parental indicators and their association with healthy weight and overweight/obese children's physical activity

Background

Although it is accepted that parents play a key role in forming children’s health behaviours, differences in parent-child physical activity (PA) have not previously been analysed simultaneously in random samples of families with non-overweight and overweight to obese preschool and school-aged children. This study answers the question which of the health-related parental indicators (daily step count (SC), screen time (ST), and weight status and participation in organized leisure-time PA) help their children achieve the step count recommendations.

Methods

A nationally representative sample comprising 834 families including 1564 parent-child dyads who wore the Yamax Digiwalker SW-200 pedometer for at least 8 h a day on at least four weekdays and both weekend days and completed a family log book (anthropometric parameters, SC, and ST). Logistic regression analyses were used to investigate whether parental achievement of the daily SC recommendation (10,000 SC/day), non-excessive ST (< 2 h/day), weight status, and active participation in organized PA were associated with children’s achievement of their daily SC (11,500 SC/day for pre-schoolers and 13,000/11,000 SC/day for school-aged boys/girls).

Results

While living in a family with non-overweight parents helps children achieve the daily SC recommendation (mothers in the model: OR = 3.50, 95% CI = 2.29–5.34, p < 0.001; fathers in the model: OR = 2.41, 95% CI = 1.37–4.26, p < 0.01) regardless of their age category, gender, or ST, for families with overweight/obese children, only the mother’s achievement of the SC recommendations and non-excessive ST significantly (p < 0.05) increase the odds of their children reaching the daily SC recommendation. The active participation of children in organized leisure-time PA increases the odds of all children achieving the daily SC recommendations (OR = 1.80–2.85); however, for overweight/obese children this remains non-significant. The participation of parents in organized leisure-time PA does not have a significant relationship to the odds of their overweight/obese or non-overweight children achieving the daily SC recommendations.

Conclusions

The mother’s health-related behaviours (PA and ST) significantly affect the level of PA of overweight/obese preschool and school-aged children. PA enhancement programmes for overweight/obese children cannot rely solely on the active participation of children in organized leisure-time PA; they also need to take other family-based PA, especially at weekends, into account.

The home electronic media environment and parental safety concerns: relationships with outdoor time after school and over the weekend among 9-11 year old children

BACKGROUND

Time spent outdoors is associated with higher physical activity levels among children, yet it may be threatened by parental safety concerns and the attraction of indoor sedentary pursuits. The purpose of this study was to explore the relationships between these factors and outdoor time during children's discretionary periods (i.e., after school and over the weekend).

METHODS

Data from 462 children aged 9-11 years old were analysed using generalised linear mixed models. The odds of spending > 1 h outdoors after school, and > 2 h outdoors on a weekend were computed, according to demographic variables, screen-based behaviours, media access, and parental safety concerns. Interactions with sex and socioeconomic status (SES) were explored.

RESULTS

Boys, low SES participants, and children who played on their computer for < 2 h on a school day had higher odds of spending > 1 h outside after school than girls, high SES children and those playing on a computer for ≥2 h, respectively. Counterintuitive results were found for access to media devices and crime-related safety concerns as both of these were positively associated with time spent outdoors after school. A significant interaction for traffic-related concerns*sex was found; higher road safety concerns were associated with lower odds of outdoor time after school in boys only. Age was associated with weekend outdoor time, which interacted with sex and SES; older children were more likely to spend > 2 h outside on weekends but this was only significant among girls and high SES participants.

CONCLUSIONS

Our results suggest that specific groups of children are less likely to spend their free time outside, and it would seem that only prolonged recreational computer use has a negative association with children's outdoor time after school. Further research is needed to explore potential underlying mechanisms, and parental safety concerns in more detail.

Mothers' Perceived Neighbourhood Environment and Outdoor Play of 2- to 3.5-Year-Old Children: Findings from the Healthy Beginnings Trial

Background: This study aims to investigate whether mothers’ perceived neighbourhood environment is associated with outdoor playtime of 2- to 3.5-year-old children. Methods: Cross-sectional analyses were conducted using data from the Healthy Beginnings Trial (HBT). Data on children’s outdoor playtime and mothers’ perceived neighbourhood environment were collected through face-to-face interviews with mothers when their children were 2 and 3.5 years old. Walk score was obtained from a publicly available website and population density data were obtained from Australian Census data. Multiple logistic regression models were built to investigate these associations. Results: A total of 497 and 415 mother-child dyads were retained at 2 years and 3.5 years. After adjusting for intervention group allocation and other confounding factors, at 2 years, mothers’ perceptions that ‘the neighbourhood is a good place to bring up children’, ‘it is safe to play outside during the day’, and ‘there are good parks or playgrounds in neighbourhood’ were positively associated with children’s outdoor playtime. At 3.5 years, living in a free-standing house was associated with more children’s outdoor playtime. Conclusions: Children may benefit from living in a neighbourhood that supports active lifestyle. Improving social and physical environments in neighbourhoods could be an important strategy for improving young children’s physical activity.

Correlates of Insufficient Physical Activity among Junior High School Students: A Cross-Sectional Study in Xi'an, China

Background: Physical activity plays an important role in individual health at all stages of life. However, evidence is lacking regarding the level of moderate to vigorous physical activity (MVPA) and the related factors to insufficient physical activity (IPA). Methods: A sample of 1060 students aged 12–15 years from nine public junior high schools in China were invited to participate in this study. Physical activity was assessed by a modified version of the International Physical Activity Questionnaire. Logistic regression was used to assess the factors associated with IPA. Results: 30.1% boys and 43.0% girls in our sample did not engage in sufficient physical activity. Obesity (OR = 2.2, 95% CI: 1.5–2.9) and high socioeconomic status (SES) (OR = 2.4, 95% CI: 1.3–4.8) were positively associated with IPA, whereas male sex (OR = 0.7, 95% CI: 0.5–0.9), underweight status (OR = 0.5, 95% CI: 0.3–0.7), and high family support level for physical activity (OR = 0.7, 95% CI: 0.6–0.9) showed inverse associations. Age was not associated with IPA. Conclusions: IPA appears to be a considerable problem in this sample of Chinese youth. Effective interventions to increase physical activity are needed and may include improving family support level for physical activity, especially for girls, the obese and those with high SES.

Relationship between Brazilian adolescents' physical activity and social and economic indicators of the cities where they live

This study investigated the relationship between sufficient amounts of physical activity among Brazilian adolescents and the economic and social indicators of the cities where they live. Data from a large national survey including 109,104 boys and girls ages 13 to 15 yr. (47.8% boys, 52.2% girls) were analyzed. The economic and social indicators were the Human Development Index (HDI), which is a comparative measure to rank cities according to their degree of human development, the Gini index (income inequality), population density, and maternal education. Stepwise regression was used to identify associations between physical activity and economic and social indicators of the cities. The physical activity of Brazilian adolescents was associated with the social and economic conditions of the cities where they live. The amount of physical activity of girls was greater in the cities with fewer income inequalities. For boys, physical activity was greater in the cities with a higher HDI and fewer income inequalities.