Determinants of Change in Physical Activity in Children During the Transition from Elementary to High School

INTRODUCTION

Effective public health interventions targeting factors that influence physical activity are urgently needed to reduce the age-related decline in physical activity in youth. The purpose of this study was to identify associations between physical activity and a set of potential influences on physical activity in children as they transition from elementary to high school.

METHODS

Participants were 951 children from South Carolina school districts who completed outcome and independent variable measures on at least two time points from the 5th through 11th grades in 2010 - 2017. The primary outcome variable was physical activity, measured by accelerometry. Independent variables included a comprehensive set of variables in the child, parent/home, school, and community domains. Children, parents and school administrators, and staff completed questionnaires to assess psychosocial and home, school, and neighborhood environmental influences. Growth curve analyses identified independent variables associated with physical activity over time, either as a main effect or as an interaction with age.

RESULTS

As main effects, self-efficacy, self-schema, sport participation, weekday outdoor hours, importance of child participating in sports and physical activity, safe to play outside, and Physical Activity Resource Assessment weighted score were positively associated with physical activity. The associations between physical activity and enjoyment motivation, appearance motivation, weekend outdoor time, and home equipment exhibited significant interactions with age. Enjoyment motivation influenced physical activity during the earlier years, whereas the remaining three variables influenced physical activity in the later years.

CONCLUSIONS

Interventions should target multiple domains of influences that may vary by age.

Clustering Patterns of 24-Hour Physical Activity in Children 6-36 Months Old

PURPOSE

To determine 24-hour physical activity (PA) clusters in children 6-36 months of age, factors associated with the clusters, and their agreement across time.

METHOD

A longitudinal study followed 150 infants from South Carolina up to 36 months of age. Measures included 24-hour PA and demographic data. Functional clustering was used to obtain the clusters. The association between cluster membership and infant/parent characteristics was examined by Kruskal-Wallis and chi-squared tests. Concordance was measured with the kappa coefficient and percent agreement.

RESULTS

At each follow-up, 3 clusters were optimal, identified as late activity (cluster 1), high activity (cluster 2), and medium activity (cluster 3). The defining feature of the late activity cluster was that their physical activity (PA) activity was shifted to later in the day versus children in clusters 2 and 3. At 6 months, the clusters were associated with race (<0.001), crawling (0.043), other children in the household (0.043), and mother's education (0.004); at 12 months with race (0.029), childcare (<0.001), and education (<0.001); and at 36 months with other children in the household (0.019). Clusters showed moderate agreement (kappa = .41 [.25 to .57], agreement = 61% [49% to 72%]) between 6 and 12 months and, at 36 months, showed no agreement with either 6 or 12 months.

CONCLUSION

Twenty-four-hour PA can be clustered into medium, high, and late PA. Further research is needed into the consequences of late sleeping in children at this age. Clusters are associated with household and childcare factors, and cluster membership is dynamic across time.

Association of physical activity, sedentary behavior, diet quality with adiposity: a longitudinal analysis in children categorized by baseline weight status

BACKGROUND/OBJECTIVES

Childhood obesity rates have increased in recent years. The effectiveness of future public health interventions to reduce childhood obesity will be enhanced by a better understanding of behavioral factors that influence adiposity in children as they transition from childhood to adolescence. The purpose of this study was to examine whether initial weight status modifies the longitudinal associations of physical activity, sedentary behavior, and diet quality with changes in adiposity over time.

SUBJECTS/METHODS

A total of 658 children (45% boys) were stratified into 3 groups based on 5th grade BMI percentiles ( < 85th, 85-95th, > 95th) and followed from 5th grade to 6th and/or 7th grade. Study variables, including fat-mass-index (FMI), moderate-to-vigorous physical activity (MVPA), diet quality, and sedentary behavior, were measured at 5th, 6th, and/or 7th grades. Separate growth curve models were conducted within each weight status group to examine the associations between MVPA, sedentary behavior, diet quality and adiposity, operationalized as FMI. All models controlled for sex, maturity offset, race, and parent education.

RESULTS

Of the 658 children, 53% were classified with normal weight at baseline, 18% with overweight, and 29% with obesity. Associations between MVPA, sedentary behavior, diet quality and FMI varied within each weight status group. MVPA was negatively associated with adiposity (FMI) for all weight status groups. Diet quality and sedentary behavior were associated with adiposity only in children with obesity at baseline; neither diet quality nor sedentary behavior was associated with FMI for those with overweight.

CONCLUSIONS

MVPA was negatively associated with adiposity (FMI) in all weight status groups, suggesting that MVPA may protect against higher adiposity. Sedentary behavior and diet quality were associated with adiposity only in children with obesity at baseline; neither sedentary behavior nor diet quality was associated with FMI for children with overweight.

Longitudinal changes in domains of physical activity during the transition from elementary school to high school in the U.S

OBJECTIVES

To describe patterns of age-related change in self-reported physical activity domains within a heterogeneous sample of boys and girls in the U.S. transitioning from elementary to high school.

DESIGN

Prospective cohort study.

METHODS

Participants included n = 644 children recruited in 5th grade (10.5 ± 0.5 years old, 45 % female) who completed the Physical Activity Choices survey at least twice over 5 time points (5th, 6th, 7th, 9th and 11th grade). Participants' self-reported physical activities were categorized into organized and non-organized activities, and a comprehensive variable was created as the product of the total number of physical activities reported in the past 5 days, the number of days spent in each activity, and the total time spent in each activity. Descriptive statistics and growth curve models (controlling for covariates) for the total sample and by sex were examined for total, organized, and non-organized physical activities from ages 10 to 17.

RESULTS

There was a significant age by gender interaction (p < 0.05) for time spent in non-organized physical activities. Specifically, both sexes had similar patterns of decline before age 13, while boys increased after age 13 and girls declined and then maintained. In contrast, boys and girls declined in organized physical activities from ages 10 to 17 (p < 0.001).

CONCLUSIONS

We observed stark differences in the age-related change between organized and non-organized physical activities and marked differences in the patterns of non-organized physical activities between boys and girls. Future research should examine physical activity interventions that consider age-, sex-, and domain-specific physical activity options for youth.

Longitudinal Associations of Cardiorespiratory Fitness and Poverty With Academic Performance Among Youth

BACKGROUND

Cardiorespiratory fitness (CRF) plays a significant role in health and academic performance in youth. The purpose of this study was to examine the longitudinal relationship between CRF and academic performance from fifth to eighth grade among a large, diverse, and state-wide cohort of students, and to determine the extent to which the relationship between change in CRF and academic performance is moderated by poverty status.

METHODS

CRF and academic performance data were obtained for a retrospective state-wide cohort of 11,013 students with baseline (fifth grade, school year 2015-2016) and follow-up (eighth grade, school year 2018-2019) data. Analysis of covariance was used to examine the association between changes in CRF over a 3-year follow-up period and eighth grade academic performance.

RESULTS

After adjusting for covariates, change in CRF and poverty status were positively and significantly associated with eighth grade academic performance. Poverty status did not significantly moderate the association between changes in CRF and academic performance.

CONCLUSIONS

Schools should prioritize evidence-based policies and programs that optimize students' access to high quantity and quality physical activity throughout the school day. Such efforts can improve and maintain student CRF and thus academic performance outcomes.

Factors Related to High-School Students’ Odds of Having Overweight or Obesity

This study used data the Youth Risk Behavior Surveillance System ( N = 7,088) to examine factors associated with the odds of overweight/obesity. Overweight/obese was defined as a body mass index ≥85th percentile, based on age- and sex-specific growth charts. Participants were categorized into meeting/not meeting guidelines for: sleep, moderate-to-vigorous PA (MVPA), muscle strengthening PA, screen time, breakfast eating, fruit and vegetable consumption, and soda and milk consumption. Logistic regression analyses determined whether meeting guidelines for each health behavior was associated with the odds of students having overweight/obesity in the total group and stratified by sex. Meeting MVPA guidelines was the only behavior associated with having a lower odds of overweight/obesity in both sexes. For females, meeting recommendations for breakfast eating and strength training were also associated with lower odds of having overweight/obesity, whereas for boys, getting the recommended amount of sleep was associated with having lower odds of overweight/obesity. Interventions to reduce the prevalence of overweight/obesity in youth should be implemented inside and outside of the school environment and should include components addressing physical activity, diet, and sleep. Such interventions should address barriers to healthy behaviors that are unique to adolescents already affected by overweight/obesity.

A Summary of One Research Team's Contributions to Understanding Physical Activity Behavior in Children and Youth

Schools are well-positioned to provide physical activity opportunities to help youth achieve the recommended 60 or more daily minutes of moderate-to-vigorous physical activity. The Children's Physical Activity Research Group (CPARG) at the University of South Carolina has focused on understanding physical activity in school-aged youth for 30+ years. The purpose of this article was to critically review (CPARG) contributions to the field in school settings and school-age youth. We reviewed 127 published CPARG articles from six research projects conducted between 1993-2019. The review was guided by questions in five categories: measurement of physical activity and its determinants, characteristics of physical activity behavior, correlates/determinants of physical activity, physical activity interventions, and race/ethnicity and physical activity. Results were summarized by question and synthesized across categories. CPARG contributions included assessing physical activity levels, patterns, forms, and contexts; identifying and measuring physical activity correlates/determinants; and conducting school-based physical activity interventions. Identifying multiple domains of physical activity determinants enables researchers and practitioners to select/design age-appropriate, valid, and reliable instruments to assess determinants. Focusing on determinants enables them to create effective physical activity interventions, environments, programs, and policies in schools. These efforts must address race/ethnicity differences, ensuring that measurement instruments and intervention strategies are culturally appropriate.

Behavioral, Environmental, and Demographic Factors Associated with Objectively Measured Physical Activity in Infants

Background: To describe objectively measured physical activity (PA) in infants, and to identify demographic, behavioral, and environmental factors associated with infants' PA. Methods: Participants were 6-7-month-old infants and their mothers (N = 143 dyads) from two Southeastern US counties. Infant measures included PA assessed by accelerometers at ankle and waist sites, motor developmental status (i.e., stationary and locomotion), and anthropometric characteristics (i.e., height and weight). Mothers provided information on home environment, child care settings, and family demographic factors. PA levels were compared across demographic subgroups. Correlation coefficients described associations between PA and continuous variables, including motor developmental status and anthropometric characteristics. Multiple linear regression analyses examined factors found to be independently associated with PA. Results: Infants' PA counts were greater at the ankle (77,700 counts/hr) vs. the waist site (32,500 counts/hr). In univariate analyses, a diverse set of environmental, behavioral, and infant-level demographic factors were found to be significantly associated with PA at the ankle site. Multivariate analyses indicated that more advanced motor development status (B = 666.3 ± 329.8, p < 0.05), attendance at home child care settings (B = -13,724.4 ± 5083.9, p < 0.05), greater exposure to tummy time (B = 213.5 ± 79.9, p < 0.05), and white racial/ethnic composition (B = -19,953.4 ± 5888.5, p < 0.01) were independently, associated with infants' PA. Conclusions: In 6-7-month-old infants, objectively measured PA was found to be associated with motor developmental status and physical and social environmental factors, including both demographic moderators and factors that are influenced by parents and caregivers. Longitudinal studies are needed to determine if these relationships persist or change as infants develop.

Patterns of age-related change in physical activity during the transition from elementary to high school

This study was designed: 1) to describe patterns of age-related change in total and moderate-to-vigorous physical activity (MVPA) in children as they transitioned from elementary school to high school, and 2) to determine if those patterns differed across demographic sub-groups formed on the basis of gender, race/ethnicity, parent education (socioeconomic status), and urbanicity. A cohort of children (analysis sample, N = 951) was comprised of students drawn from two public school districts in South Carolina. Physical activity was measured by accelerometry on at least two and up to five occasions between 2010 and 2017. Growth curve analyses were performed to describe the pattern of age-related change in the physical activity variables for the full sample and for demographic sub-groups. A relatively steep age-related decline in total physical activity was observed in children before age 14, with a slower rate after that age. Physical activity was lower in girls than boys, and the age-related rate of decline was steeper in girls. Physical activity patterns did not differ across race/ethnicity groups, but children of parents with less education were more active than children of parents with more education. Children living in rural areas participated in less MVPA than children living in urban settings, and this difference increased with increasing age. These findings indicate that children experience a particularly steep decrease in physical activity as they transition from elementary to middle school, and this trend is particularly prominent in girls, children living in rural areas, and children of parents with college education.

Longitudinal association of biological maturation with physical activity behaviors in girls transitioning from 5th to 7th grade

Introduction

This longitudinal study determined if social cognitive variables influence physical activity in girls stratified on the basis of maturity status.

Methods

Participants attended South Carolina public schools (Mage in 5th grade = 11.1 years) and included a cohort of 529 girls who provided physical activity data in the 5th grade and in 6th and/or 7th grade. The measure of maturity status was age at peak height velocity (APHV) estimated from maturity offset when the children were in the 5th grade. The Earlier Maturity (EM) group included girls whose APHV was one standard deviation or more below the mean APHV for the full sample. All other girls were placed in the Later Maturity (LM) group. Physical activity was assessed at each time point via accelerometry. Social‐cognitive variables were assessed at each time point by a questionnaire measuring self‐efficacy, enjoyment, competence, appearance, fitness, and social motives for physical activity. Growth curves for the total, Earlier Maturing, and Later Maturing groups assessed relationships between physical activity over time and time‐varying social cognitive variables.

Results

Physical activity was lower in the Earlier Maturing group and was positively associated with self‐efficacy and enjoyment motivation in the total group. These relationships were observed in the 5th grade and maintained through 7th grade. In the Later Maturing group, we observed positive relationships between physical activity and self‐efficacy, enjoyment and competence motivation.

Conclusions

Strategies to increase confidence, skills, and enjoyment of physical activity may only be effective for promoting activity among later maturing girls.

Nighttime sleep and physical activity in 6-7 month-old infants

This study examined associations between objectively-measured nighttime sleep duration and physical activity in a sample of 6-7 month-old infants (N=93). The study also investigated relationships between infant sleep and demographic and environmental characteristics. Cross-sectional relationships were assessed using linear regression analyses. Nighttime sleep duration was positively associated with physical activity levels. Nighttime sleep duration was greater when infants had a consistent bedtime, slept in a separate room, were male, and had mothers who reported having a college education or greater. These findings can inform the development of interventions that aim to improve infant sleep.

The role of parental support for youth physical activity transportation and community-level poverty in the healthy communities study

This study evaluates whether parental provision of transportation for physical activity is associated with child/adolescent moderate-to-vigorous physical activity, while also evaluating community-level poverty. Self- and parental-reported surveys were administered with parents/caregivers and children in the Healthy Communities Study (N = 5138). Associations between individual-level demographics, community-level poverty, parental provision of transportation for physical activity, and moderate-to-vigorous physical activity were examined in multi-level models. Even when accounting for community-level poverty, which was significantly associated with lower moderate-to-vigorous physical activity, parental provision of transportation for physical activity was positively associated with greater moderate-to-vigorous physical activity. This study provides evidence for the importance of considering multiple systems of influence (e.g., community and individual factors) and considering how gaps in physical activity transportation for youth can be addressed in future health policies.

Associations between three measures of physical activity and selected influences on physical activity in youth transitioning from elementary to middle school

Measurement of physical activity is challenging, and objective and subjective methods can be used. The purposes of this study were to apply structural equation modeling in: 1) examining the associations between three distinct measures of physical activity and three factors that are often found to be correlated to physical activity in children, and 2) examining the associations of the combination of three measures with the same correlates in a cohort of youth followed from 5th to 7th grade. A total of 409 children (45% boys) had complete physical activity data derived from accelerometers, self-report by youth, and proxy-report by parents. The potential correlates of physical activity included self-efficacy, physical activity support, and facilities for physical activity. Structural equation models were used to assess the relationship between physical activity and the correlates. The structural equation models examining associations between individual measures of physical activity and selected correlates showed that parent-reported and child self-reported physical activity were associated with parental support for physical activity and self-efficacy. Objectively measured physical activity was associated only with facilities for physical activity. A structural equation model showed that a composite expression of physical activity, based on the inclusion of all three individual measures, was associated with all three correlates of physical activity. In conclusion, combining measures of physical activity from different sources may improve the identification of correlates of physical activity. This information could be used to plan more effective physical activity interventions in children and youth.

Changes in Diet Quality in Youth Living in South Carolina From Fifth to 11th Grade

OBJECTIVE

To examine diet quality levels and changes in a diverse sample of youth from fifth to 11th grade, and interactions by race/ethnicity and socioeconomic status.

DESIGN

Transitions and Activity Changes in Kids prospective cohort study.

SETTING

Elementary, middle, and high schools in South Carolina.

PARTICIPANTS

A sample of 260 fifth-graders (106 boys and 154 girls) with complete data at baseline and at least 1 time point each in middle school and in high school.

MAIN OUTCOME MEASURE

Dietary intake assessed with the Block Food Screener for Kids (last week). Diet quality was assessed using energy-adjusted intakes of 5 food groups.

ANALYSIS

Descriptive statistics and growth curve models for the total group and by gender for diet quality from fifth to 11th grade (P < 0.05).

RESULTS

Both boys and girls had low levels of diet quality, which continued to decline through 11th grade. Significant main effects by race and poverty as well as a race by poverty interaction were observed.

CONCLUSIONS AND IMPLICATIONS

Programs and policies that support healthy dietary patterns in children transitioning from elementary to middle and high school are needed. Specific efforts that focus on nutrition disparities in children from low-income and minority backgrounds are warranted.

Neighborhood Socioeconomic Deprivation Associated with Fat Mass and Weight Status in Youth

(1) Background: Few studies have examined the relationship between neighborhood socioeconomic deprivation (SED) and weight-related outcomes in youth, controlling for weight-related behaviors. Hence, the purpose of this study was to examine the association between neighborhood SED, weight status, and fat mass in a diverse sample of youth, before and after controlling for physical activity and diet. (2) Methods: The sample included 828 youth from the Transitions and Activity Changes in Kids study. Neighborhood SED was expressed as an index score at the census tract of residence. Height, weight, and body composition were measured and used to calculate fat mass index (FMI) and weight status. Moderate-to-vigorous physical activity (MVPA) and sedentary behavior (min/h) were measured via accelerometry. Diet quality was assessed via the Block Food Screener for Kids. Multilevel regression models were employed to examine these relationships. (3) Results: Neighborhood SED was significantly associated with FMI and weight status before and after controlling for MVPA, sedentary behavior, and diet. Notably, youth residing in the most deprived neighborhoods had significantly higher FMI and were 30% more likely to be overweight/obese (OR = 1.30; 95% CI = 1.03-1.65). (4) Conclusions: Greater neighborhood SED was consistently and significantly associated with higher fat mass index and increased likelihood of overweight/obesity among youth.

Poverty Status Moderates the Relationship between Cardiorespiratory Fitness and Academic Achievement

BACKGROUND

The purpose of the study was to examine the associations among cardiorespiratory fitness (CRF), weight status and academic achievement in youth, and to determine if these relationships are moderated by poverty status.

METHODS

The sample included 5th (N = 27,791) and 8th grade (N = 16,047) South Carolina students. Academic achievement was assessed using a state-wide assessment and classified into 2 categories (ie, does not meet/approaches standards vs meets/exceeds standards). CRF was assessed and expressed as Healthy Fitness Zone (HFZ) or Needs Improvement/Needs-Improvement-Health Risk. Students' demographics and poverty status were reported. Multilevel logistic regression analyses were used to examine the association between CRF, weight status and academic achievement. Interaction terms were introduced into the final models. Analyses were performed separately by grade level and academic subject.

RESULTS

The CRF was significantly associated with the odds of meeting/exceeding academic standards after controlling for covariates and adjusting for weight status. The relationship between CRF and academic achievement varied significantly by poverty status. After adjustment for CRF, weight status was not significantly associated with academic achievement.

CONCLUSIONS

The odds of achieving academic standards were significantly higher among students achieving CRF HFZ regardless of poverty status. CRF may partially mitigate the adverse effect of poverty on academic achievement.

Linking Activity, Nutrition, and Child Health (LAUNCH): protocol for a longitudinal cohort study of children as they develop from infancy to preschool age

BACKGROUND

Physical activity is known to provide important health benefits in children ages 3 years and above, but little is known about the effects of physical activity on health in very young children under age 3. LAUNCH (Linking Activity, Nutrition, and Child Health) is a study designed to expand the body of knowledge on development of physical activity behavior and associations between physical activity and other health characteristics as children transition from infancy to preschool age.

METHODS

Physical activity and sedentary behavior will be measured objectively in young children over a period of 30 months. Each child will complete a measurement protocol at 6, 12, 18, 24, 30 and 36 months of age. The following factors will be measured at each time point: physical activity, sedentary behavior, anthropometric characteristics, and motor developmental status. Objectively-measured sleep behavior will be included as an optional component of the protocol. Parents will provide information on demographic factors, parenting behaviors, home and childcare characteristics, and the child's dietary and sleep behaviors.

DISCUSSION

LAUNCH will employ a longitudinal study design and objective measures of physical activity, sedentary behavior and sleep in examining developmental trends for those characteristics in children between the ages of 6 and 36 months. Associations among physical activity, sedentary behavior, sleep, and weight status will be examined. Findings will inform public health guidance and intervention strategies for very young children.

Cross-Country Comparisons of Physical Activity and Sedentary Behavior among 5-Year-Old Children

PURPOSE

Previous studies have observed that physical activity (PA) levels tend to be lower in the U.S. population than in many other countries. Within the U.S., PA levels in children are lower in the South than in other regions. Cross-country and interregional differences in PA have not been studied in young children.

METHODS

In an ongoing study of children at genetic risk for Type 1 diabetes, PA was measured by accelerometry in samples of 5-year-old children (n = 2008) from Finland (n = 370), Germany (n = 85), Sweden (n = 706), and the U.S. (n = 847). The U.S. sample was drawn from centers in Washington State, Colorado, and Georgia/Florida. Children wore accelerometers for 7 days, and the data were reduced to daily minutes of light-, moderate- (MPA), vigorous- (VPA), and moderate-to-vigorous- (MVPA) intensity PA and sedentary behavior. Multiple regression was used to compare children across countries and across regions in the U.S, adjusting for wear time, body mass index, and demographic characteristics.

RESULTS

After adjusting for previously mentioned factors, MVPA and MPA were lower in U.S. children than those in Finland and Sweden. Estimates of physical activity were higher in Finland than in other countries, although not all comparisons were significantly different. U.S children spent significantly more time in sedentary behavior than children in Finland (p < 0.0001). Within the U.S., children's PA was consistently lowest in Georgia/Florida and highest in Washington.

CONCLUSIONS

Cross-country differences in PA, previously reported for adults and adolescents, are evident in 5-year-old children. In general, PA levels are lower in U.S. children than their European counterparts, and within the U.S., are lower in Georgia/Florida and Colorado than in Washington. Future studies should be designed to identify the factors that explain these differences.

Childcare Center Characteristics Moderate the Effects of a Physical Activity Intervention

Center-based early childhood education and care (ECEC) programs are well-positioned to create positive impacts on the health and development of large numbers of young children by promoting physical activity using evidence-based programs. Studies testing physical activity programs for young children should examine the circumstances under which programs are most effective by assessing the role of contextual factors on program outcomes. The purpose of this study was to examine the moderating effects of baseline ECEC center characteristics on the relationship between the Study of Health and Activity in Preschool Environments (SHAPES) intervention and moderate-to-vigorous physical activity (MVPA). MVPA was assessed via accelerometry; center characteristics, practices, and social and physical environments were assessed by director interview and observation; and center quality was assessed using the Early Childhood Environment Rating Scale-Revised Edition. Mixed-model analyses of covariance (ANCOVAs) examined intervention effects on MVPA during the school day; interactions between baseline center variables and group assignment (intervention vs. control) tested for moderation. Two center instructional practices, two social environment characteristics, and one physical environment characteristic at baseline moderated the effects of SHAPES on MVPA outcomes. Assessing baseline practices and center characteristics may aid efforts to match centers with interventions likely to increase physical activity as well as suggest additional intervention strategies to test.

Sport participation, physical activity and sedentary behavior in the transition from middle school to high school

OBJECTIVES

To examine associations between sport participation, and objectively assessed physical activity and sedentary behavior in youth during the transition from middle school to high school.

DESIGN

Longitudinal study with 2-year follow-up.

METHODS

Sport participation and accelerometer-measured physical activity and sedentary behavior were assessed in 306 children (122 males, 184 females) when they were in 7th and 9th grades (mean age of 12.5 ± 0.5 years).

RESULTS

Sport participation and physical activity declined from 7th to 9th grade, but total physical activity (d = 0.38, p < 0.0001) and moderate-to-vigorous physical activity (d = 0.26, p = 0.0004) remained higher in sport participants compared to non-participants. In 9th grade, the full sample of sport participants compared to non-participants had higher levels of total physical activity (20.7 min/h vs. 18.5 min/h) and moderate-to-vigorous physical activity (1.8 min/h vs. 1.6 min/h). Sex-specific analysis revealed similar patterns in both females and males. Sedentary behavior remained lower (d = -0.37, p = <0.0001) in the full sample of sport participants compared to non-participants (39.8 min/h vs. 41.7 min/h) in 9th grade. Similar patterns were observed in both females and males.

CONCLUSIONS

Children's participation in sport is associated with greater levels of physical activity and lower levels of sedentary behavior during the transition from middle school to high school. Promoting children's participation in sports could be an effective public health strategy to help children meet the current physical activity guideline.

Associations among Neighborhood Socioeconomic Deprivation, Physical Activity Facilities, and Physical Activity in Youth during the Transition from Childhood to Adolescence

Background: This study aims to examine the longitudinal association of neighborhood socioeconomic deprivation (SED) with physical activity in youth during the transition from elementary to middle school, and to determine if access to physical activity facilities moderates this relationship. Methods: Data were obtained from the Transitions and Activity Changes in Kids (TRACK) study, which was a multilevel, longitudinal study designed to identify the factors that influence changes in physical activity as youth transition from elementary to middle school. The analytic sample for the current study included 660 youth with complete data in grades 5 (baseline) and 7 (follow-up). A repeated measures multilevel framework was employed to examine the relationship between SED and physical activity over time and the potential moderating role of elements of the built environment. Results: Decreases in physical activity varied by the degree of neighborhood SED with youth residing in the most deprived neighborhoods experiencing the greatest declines in physical activity. Access to supportive physical activity facilities did not moderate this relationship. Conclusion: Future research studies are needed to better understand how neighborhood SED influences youth physical activity over time.

Self-efficacy, beliefs, and goals: Moderation of declining physical activity during adolescence

OBJECTIVE

To examine whether the decline in physical activity observed from childhood through adolescence is explained by moderating effects of self-efficacy on concurrent changes in children's goals and beliefs about their physical activity environments.

METHOD

Latent growth modeling was used in longitudinal tests in a cohort of 79 boys and 108 girls assessed in 5th, 6th, 7th, 9th, and 11th grades.

RESULTS

Physical activity measured objectively by an accelerometer declined most in students who had bigger declines in self-efficacy and (1) maintained higher perceptions of barriers to physical activity, (2) had bigger declines in enjoyment and fitness goals, or (3) had smaller declines in appearance and social goals.

CONCLUSIONS

Trials of physical activity interventions based on social-cognitive theory should consider that the influence of changing goals on physical activity may differ according to whether students maintain high efficacy beliefs about overcoming barriers to physical activity coincident with perceptions of their physical activity environment. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Moderating effect of the neighbourhood physical activity environment on the relation between psychosocial factors and physical activity in children: a longitudinal study

Background

Few studies have examined the moderating role of neighbourhood environments on the relation between psychosocial factors and physical activity, and results of these studies are mixed. This study examined this relationship in 636 fifth to seventh graders from South Carolina, USA.

Methods

From 2010 to 2013, children and their parent/guardian completed annual self-reported surveys assessing psychosocial factors, and children wore accelerometers for 1 week each year. Neighbourhood environments were classified as supportive or non-supportive for physical activity (PA) based on in-person audits of facilities near children’s homes and windshield surveys of children’s streets. Growth curve analyses were completed to assess the moderating effect of the neighbourhood physical activity environment (NPAE) on the relation between psychosocial factors and total physical activity (TPA) over time.

Results

Significant interactions on TPA were found for (1) time, NPAE and parent-reported parent support for PA; (2) time, NPAE and child-reported equipment in the home; (3) child-reported parental support for PA and time; (4) child-reported parental support for PA and NPAE; (5) PA self-schema and time and (6) child-reported parental encouragement and time. Parental support and a supportive NPAE were important for TPA, especially as children transitioned to middle school, whereas home equipment and a supportive NPAE were important for fifth graders’ TPA.

Conclusion

Consistent with the socioecological model, PA behaviour was dependent on interacting effects across levels of influence. Generally, both a supportive NPAE and positive psychosocial factors were needed to support TPA. Factors influencing PA across multiple levels should be addressed in PA interventions.

EASY-An Instrument for Surveillance of Physical Activity in Youth

PURPOSE

Physical activity (PA) promotion among youth is a public health priority, and there is a need for robust surveillance systems to help support such initiatives. Existing youth PA self-report instruments that are used for surveillance lack information regarding the types and contexts of activity. Further, these instruments have limited validity with accelerometry. The purpose of the present study was to develop a self-report instrument, with sound psychometric properties, for monitoring compliance with PA guidelines in youth.

METHODS

In focus groups, 162 middle school students identified 30 forms of PA that are highly prevalent in that age-group. We incorporated these activities into three preliminary forms of a self-report instrument. An independent sample of middle school students (n = 537) was randomly assigned to complete one of the three preliminary versions of the instrument. Rasch analysis was applied to the responses to the three formats, and a yes/no plus frequency format emerged as the preferred method. A third sample of 342 middle school students then completed the yes/no plus frequency instrument twice after a 7-d period during which they wore an accelerometer. Using both Rasch analysis and traditional correlational methods, validity and reliability of a 14-item instrument were established. Data were collected during 2012-2015.

RESULTS

Spearman correlation coefficient for the association between the cumulative score for the 14 items and minutes per day of accelerometry-derived moderate-to-vigorous physical activity was 0.33 (95% confidence interval = 0.22-0.43, P < 0.001). The sensitivity and specificity values of the 14-item instrument were 0.90 and 0.44, respectively.

CONCLUSIONS

The study produced a PA self-report instrument for youth that was found to be reliable (r = 0.91), valid versus accelerometry (r = 0.33), and with acceptable specificity and sensitivity in detecting compliance with PA guidelines.

Group-based physical activity trajectories in children transitioning from elementary to high school

Background

Physical activity has been observed repeatedly to decline as children transition into adolescence; however, few studies have explored the possibility that sub-groups of children experience unique patterns of change during this transition. The purpose of this longitudinal study was to examine the physical activity trajectories in clusters of youth transitioning from 5th to 11th grade.

Methods

Participants (n = 652) were recruited as 5th graders (ages 10–12 years) from elementary schools (n = 21) in two school districts. Demographic, anthropometric, and physical activity data were collected once per year when children were in 5th, 6th, 7th, 9th, and 11th grades. Children wore accelerometers for 7 consecutive days. Group-based trajectory modeling statistical techniques were applied to identify patterns of physical activity trajectories. Posterior probabilities confirmed participants’ membership in their respective group.

Results

Three distinct physical activity trajectories were identified. Group 1 (n = 27) remained highly active over time, and physical activity increased from ages 14 to 16 years. Group 2 (n = 365) was active at baseline, but activity declined and remained low as group members aged. Group 3 (n = 260) had the lowest levels of physical activity at all ages, and activity declined from ages 10 to 16 years.

Conclusions

While most children experienced a decline in physical activity as they transitioned into high school, some remained highly active and increased their level of physical activity. Future studies should test physical activity interventions for youth that are tailored for age-related trajectory groups.

Change in Children's Physical Activity: Predictors in the Transition From Elementary to Middle School

INTRODUCTION

Interventions to promote physical activity in children should be informed by knowledge of the factors that influence physical activity behavior during critical developmental transitions. The purpose of this study is to identify, from a comprehensive, multidomain set of factors, those that are associated with change in objectively measured physical activity in children as they transition from elementary to middle school.

METHODS

The study used a prospective cohort design, with children observed in fifth, sixth, and seventh grades. Growth curve analyses were used to examine associations between exposure variables measured at baseline and children's physical activity across three observations. A total of 828 children, aged 10.6 (SD=0.5) years at baseline provided physical activity data in fifth grade and at one or both follow-ups. Exposure variables assessed child characteristics, parent characteristics, home characteristics, social factors, school environment, and community characteristics. Physical activity was measured via accelerometry. Data were collected in two school districts in South Carolina in 2010-2013 and analyzed in 2017.

RESULTS

Variables measured within the child, parent/home, and community domains were positively associated with children's physical activity as they transitioned from fifth to seventh grade. These included parent encouragement of physical activity, parental support for physical activity, child sports participation, parent's report of the child's physical activity level, the child's time spent outdoors, social spaces for physical activity in the community, and the number of physical activity facilities that were proximal to the child's home.

CONCLUSIONS

Interventions designed to increase children's physical activity should include strategies that target multiple domains of influence.

Raising an Active and Healthy Generation: A Comprehensive Public Health Initiative

Physical activity (PA) provides important health benefits to youth, but most U.S. children and adolescents fail to meet federal PA guidelines. The purpose of this article is to present a plan for a large-scale public health initiative aimed at producing population-level increases in PA among U.S. youth.

Regional comparisons of walking or bicycling for fun or exercise and for active transport in a nationally distributed sample of community-based youth

BACKGROUND

Physical activity helps prevent excessive weight gain in youth. Few studies have examined regional variations in common activities, walking and bicycling.

OBJECTIVE

The primary aim was to examine participation in previous 7-day walking/bicycling for active transport and for fun/exercise by region, gender and age groups.

METHODS

Children (n = 2693) from 130 diverse, geographically distributed US communities reported participation in previous 7-day walking/bicycling. Mixed model ANOVAs were used to compare walking/bicycling by region, gender and age groups using Healthy Communities Study data.

RESULTS

Walking/bicycling for fun/exercise was higher in the Midwest, South and West compared with the Northeast, with the same regional patterns for boys, girls and 9-11-year olds. Walking/bicycling to non-school destinations was higher in the Midwest compared with the South and Northeast, with the same pattern for girls and 9-11-year olds. Walking/bicycling to school was higher Midwest, Northeast and West compared with the South, with similar patterns for girls and 12-15-year olds.

CONCLUSIONS

Walking/bicycling for fun/exercise and to non-school destinations had higher prevalence than active transport to school. The Northeast reported lower walking/bicycling for fun/exercise; the South and Northeast reported lower walking/bicycling to non-school destinations. Program/policy initiatives should consider contextual demographic influences, as well as purpose/destination of walking/bicycling.

Relationship of objective street quality attributes with youth physical activity: findings from the Healthy Communities Study

BACKGROUND

Residential environments may significantly influence youth physical activity (PA). However, few studies have examined detailed street quality attributes via observational audits in relation to context-specific PA among youth.

OBJECTIVES

The objective of this study was to explore whether the overall quality of street environments, as well as specific attributes, was associated with neighbourhood-based and street-based PA within a national sample of youth in the Healthy Communities Study.

METHODS

Data were collected from 4616 youth from 130 communities across the USA. Youth PA in the neighbourhood and on the participant's street was captured using 7-d recall interviews. Windshield survey observational audits documented five street quality variables: burned, boarded up or abandoned residential units, litter, overall condition of residences, street type and presence of sidewalks in good condition.

RESULTS

Youth with no litter on their street reported significantly lower neighbourhood-based PA and youth living on a side street, cul-de-sac, dead-end or one-way street reported greater neighbourhood-based PA. No significant associations were detected for the overall street quality index or with street-based PA.

CONCLUSIONS

Specific street quality attributes may be associated with youth PA. Further research and collaboration between diverse disciplines and agencies should focus on understanding and improving street quality to promote youth PA and health.

Declining Physical Activity and Motivation from Middle School to High School

PURPOSE

The purpose of this study was to determine whether naturally occurring changes in intrinsic motivation, behavioral regulation, and goals mitigate declining physical activity among adolescents.

METHODS

Latent growth modeling was applied in tests of change in intrinsic motivation, facets of behavioral regulation, and their interactions with goals on change in physical activity measured by accelerometer in a cohort of 260 boys and girls evaluated longitudinally from sixth through ninth grades.

RESULTS

Physical activity declined less in youths who maintained higher intrinsic motivation or integrated regulation, but only when they maintained higher enjoyment goal compared with other students. Physical activity also declined less in students who maintained higher intrinsic motivation or integrated motivation and had bigger declines in appearance goal (or social and competence goals with intrinsic motivation) compared with students who maintained higher levels of those goals. The interactions correspond to 1 to 2 min·h less decrease in physical activity.

CONCLUSIONS

Consistent with Self-Determination Theory, the findings encourage interventions that target autonomous motivation among youths. The results extend prior evidence in three ways. First, the cohort was tracked for 3 yr using an objective measure of physical activity. Second, influences of intrinsic motivation and integrated regulation on changing physical activity were not direct. They interacted with changing goals, indicating that interventions should also focus on specific goals for physical activity as effect modifiers. Third, interventions focused on autonomous motivation should consider that controlled, introjected motivation may also interact with goals to influence physical activity during the transition between middle school and high school.

Stepping It Up: Walking Behaviors in Children Transitioning from 5th to 7th Grade

The purpose of this study was to (1) describe children's walking behaviors in 5th to 7th grade and change over time and (2) examine associations between walking behaviors and Walk Score®. Participants consisted of n = 586 students from the Transitions and Activity Changes in Kids (TRACK) Study. Children reported any walking behavior (e.g., exercise and transportation) over the past five days. Walk Score was calculated based on children's home address. Descriptive statistics summarized walking behaviors by gender and time, and repeated measure mixed models examined the relationship between walking behaviors and Walk Score. Approximately 46.8% and 19.2% of 5th grade children reported walking for exercise and transportation, respectively, and these percentages declined through 7th grade. Girls reported higher levels of total walking behavior and walking for exercise than boys (p < 0.001). Girls with a higher Walk Score had 63% higher odds of reporting walking for transportation than girls with a lower Walk Score (OR = 1.63, 95% CI = 1.02, 2.62). Walking behaviors among children were infrequent with significant declines over time, and of the nine associations examined with Walk Score, only one was significant. Efforts should prioritize frequent walking behavior and community design to increase children's physical activity.

Physical and Social Contexts of Physical Activity Behaviors of Fifth and Seventh Grade Youth

BACKGROUND

The purpose of this study was to characterize the temporal, social, and physical contexts for physical activities commonly reported in a diverse cohort of 753 boys and girls from fifth to seventh grade.

METHODS

Data were obtained from a multilevel longitudinal study, the Transitions and Activity Changes in Kids. The Physical Activity Choices instrument assessed previous 5-day participation in specific physical activities and their temporal, social, and physical contexts. Mixed model repeated measure analyses of variance and multinomial analyses examined sex differences and change over time.

RESULTS

Fifth grade boys and girls reported participation in similar activities at similar frequencies, which declined significantly by seventh grade. One temporal pattern, playing with younger children, changed over time from "both inside/outside" to "outside" school. Boys and females reported more activities performed in class/team groups over time. Most activities took place primarily at home for all participants in both grades.

CONCLUSIONS

Boys and girls reported declines in the variety and frequency of activities from fifth to seventh grade. There were sex-specific patterns in physical activities and groups; however, all participants reported home as the primary location and a shift to class/team groups over time. Schools are well-positioned to provide additional physical activity opportunities.

The Modifying Effects of Race/Ethnicity and Socioeconomic Status on the Change in Physical Activity From Elementary to Middle School

PURPOSE

Youth physical activity (PA) levels differ by race/ethnicity and socioeconomic status (SES). It is well established that various multilevel factors may influence changes in PA. The present study examined whether the association between the change in individual, interpersonal, and environmental factors and the change in PA is modified by race/ethnicity or SES.

METHODS

This study followed 643 youths and their parents from suburban and rural South Carolina participating in the Transitions and Activity Changes in Kids (TRACK) Study in 2008-2009 and 2010-2011. We assessed total PA in youth using accelerometry and categorized youth and parent survey data into blocks based on the socioecological model. Multivariate regression growth curve models evaluated whether the association between change in independent variables and change in PA was modified by race/ethnicity or SES.

RESULTS

PA declined from fifth to seventh grade among all racial/ethnic and SES groups. Associations between the range of variables and change in PA were modified by race/ethnicity but not SES. Blacks did not share any common predictors of change in PA with whites or Hispanics. However, child-reported number of active friends was associated with total PA, and enjoyment of PA was associated with change in PA among both whites and Hispanics. Significant interactions by time varied by racial/ethnic group.

CONCLUSIONS

The factors that influence changes in youth PA vary by race/ethnicity but not SES. These findings reinforce the complex nature of addressing PA behavior in diverse samples and further support the need for culturally appropriate interventions to promote PA in youth.

Changes in Physical Activity in the School, Afterschool, and Evening Periods During the Transition From Elementary to Middle School

BACKGROUND

We examined longitudinal changes in children's physical activity during the school day, afterschool, and evening across fifth, sixth, and seventh grades.

METHODS

The analytical sample included children who had valid accelerometer data in fifth grade and at least one other time-point, and provided complete sociodemographic information (N = 768, 751, and 612 for the 3 time-periods studied). Accelerometer-derived total physical activity (TPA) and moderate-to-vigorous physical activity (MVPA) were expressed in minutes per hour for the school day (∼7:45 am to 3:30 pm), afterschool (∼2:25 to 6:00 pm), and evening (6:00 to 10:00 pm) periods. We used growth curve analyses to examine changes in TPA and MVPA.

RESULTS

School day TPA and MVPA declined significantly; we observed a greater decrease from fifth to sixth grades than from sixth to seventh grades. Afterschool TPA declined significantly, but MVPA increased significantly among girls and remained stable for boys. Evening TPA decreased significantly and MVPA declined significantly in girls and remained stable among boys.

CONCLUSIONS

To inform the development of effective intervention strategies, research should focus on examining factors associated with the decline in physical activity during the transition from elementary to middle school, particularly during the hours when children are in school.

Physical Activity and Pediatric Obesity: A Quantile Regression Analysis

PURPOSE

We aimed to determine whether moderate to vigorous physical activity (MVPA) and sedentary behavior (SB) were independently associated with body mass index (BMI) and waist circumference (WC) in children and adolescents.

METHODS

Data from the International Children's Accelerometry Database were used to address our objectives (N = 11,115; 6-18 yr; 51% female). We calculated age- and gender-specific BMI and WC z-scores and used accelerometry to estimate MVPA and total SB. Self-reported television viewing was used as a measure of leisure time SB. Quantile regression was used to analyze the data.

RESULTS

MVPA and total SB were associated with lower and higher BMI and WC z-scores, respectively. These associations were strongest at the higher percentiles of the z-score distributions. After including MVPA and total SB in the same model, the MVPA associations remained, but the SB associations were no longer present. For example, each additional hour per day of MVPA was not associated with BMI z-score at the 10th percentile (b = -0.02, P = 0.170) but was associated with lower BMI z-score at the 50th (b = -0.19, P < 0.001) and 90th percentiles (b = -0.41, P < 0.001). More television viewing was associated with higher BMI and WC, and the associations were strongest at the higher percentiles of the z-score distributions, with adjustment for MVPA and total SB.

CONCLUSIONS

Our observation of stronger associations at the higher percentiles indicates that increasing MVPA and decreasing television viewing at the population-level could shift the upper tails of the BMI and WC frequency distributions to lower values, thereby lowering the number of children and adolescents classified as obese.

Naturally-occurring changes in social-cognitive factors modify change in physical activity during early adolescence

PURPOSE

To determine whether naturally-occurring changes in children's motives and beliefs are associated with the steep decline in physical activity observed from childhood to early adolescence.

METHODS

Latent growth modeling was applied in longitudinal tests of social-cognitive influences, and their interactions, on physical activity in a large cohort of boys and girls evaluated annually between 5th and 7th grades.

RESULTS

Measurement equivalence of motives and beliefs was confirmed between boys and girls. After adjustment for gender and maturity differences, physical activity declined less in children who reported the least decreases in self-efficacy for overcoming barriers to activity and perceived parental support. Physical activity also declined less in students who persistently felt they had more parental and friend support for activity compared to those who reported the largest decrease in support from friends. After further adjustment for race, the decline in physical activity was less in those who had the largest decrease in perceived barriers and maintained a favorable perception of their neighborhood environment. Changes in enjoyment and social motives were unrelated to change in physical activity.

CONCLUSION

Using an objective measure of physical activity, we confirm that naturally-occurring changes in children's beliefs about barriers to physical activity and their ability to overcome them, as well as perceptions of their neighborhood environment and social support, are concurrent with age-related declines in children's physical activity. The longitudinal findings confirm these putative social-cognitive mediators as plausible, interacting targets of interventions designed to mitigate the marked decline in physical activity that occurs during the transition between elementary and middle schools.

Physical Activity and Changes in Adiposity in the Transition from Elementary to Middle School

OBJECTIVES

This study examined the longitudinal associations of objectively measured physical activity, sedentary behavior, and diet quality with two measures of adiposity and a measure of weight status.

METHODS

A total of 658 children from 21 elementary schools (45.1% boys; 40% white, 33% black, 9% Hispanic, and 18% other race/ethnicity) were assessed at least twice in fifth, sixth, and/or seventh grade. Fat mass index (FMI), percent body fat (PBF), and BMI were calculated from body weight, standing and seated heights, and bioelectrical impedance (BIA) measured each year.

RESULTS

At follow-up, both FMI and PBF decreased among boys and increased among girls, while BMI increased in both boys and girls. After controlling for race/ethnicity, parent education, and maturity offset at baseline, growth curve analyses showed that moderate-to-vigorous physical activity (MVPA) was significantly and negatively associated with FMI, PBF, and BMI for both boys and girls. After forming tertiles of fifth grade MVPA, least-square means for FMI, PBF, and BMI were examined by grade and gender. For both boys and girls, higher MVPA was associated with lower FMI, PBF, and BMI at all three grade levels. The relationships between sedentary behavior and diet quality and FMI, PBF, and BMI were not consistent for boys or girls.

CONCLUSIONS

As boys and girls transitioned from elementary to middle school, children who participated in higher levels of MVPA maintained more favorable levels of two indicators of adiposity and a measure of weight status. These findings support the need for interventions to help children meet current public health guidelines for physical activity.

Motor competence and characteristics within the preschool environment

OBJECTIVES

Environmental characteristics within preschools that influence children's motor competence are largely unknown. The purpose of the present study was to examine the contribution of various preschool environmental characteristics to children's locomotor, object control, and total gross motor scores.

DESIGN

Cross-sectional, observational study of 3-5 year-old children (n=229) from 22 preschools in South Carolina.

METHODS

The Children's Activity and Movement in Preschool Study (CHAMPS) Motor Skills Protocol assessed MC. Preschool directors provided information regarding policies and practices. The research team measured playgrounds and classrooms, and the Early Childhood Environment Rating Scale-Revised assessed preschool quality. Time spent in open space and electronic media use were also assessed using direct observation. The aforementioned variables predicted children's object control, locomotor, and total gross motor scores.

RESULTS

Classroom size/child ratio, teacher education, playground size, electronic media use, and trips to outside organizations emerged as significant predictors of locomotor score and total motor score. The object control model was non-significant.

CONCLUSIONS

Preschools may be able to promote motor competence by allowing children more time in open spaces, structured activity experiences, and by expanding existing outdoor playground space whenever possible.

Evaluating and Refining the Conceptual Model Used in the Study of Health and Activity in Preschool Environments (SHAPES) Intervention

This study investigated the utility of the Study of Health and Activity in Preschool Environments (SHAPES) conceptual model, which targeted physical activity (PA) behavior in preschool children, by examining the relationship between implementation monitoring data and child PA during the school day. We monitored implementation completeness and fidelity based on multiple elements identified in the conceptual model. Comparing high-implementing, low-implementing, and control groups revealed no association between implementation and outcomes. We performed post hoc analyses, using process data, to refine our conceptual model's depiction of an effective preschool PA-promoting environment. Results suggest that a single component of the original four-component conceptual model, providing opportunities for moderate-to-vigorous physical activity through recess for 4-year-old children in preschool settings, may be a good starting place for increasing moderate-to-vigorous physical activity. Interventions that are implemented with optimal levels of completeness and fidelity are more likely to achieve behavior change if they are based on accurate conceptual models. Examining the mechanisms through which an intervention produces its effects, as articulated in the conceptual model that guides it, is particularly important for environmentally focused interventions because they are guided by emerging frameworks. The results of this study underscore the utility of using implementation monitoring data to examine the conceptual model on which the intervention is based.

Effects of a New State Policy on Physical Activity Practices in Child Care Centers in South Carolina

OBJECTIVES

We sought to determine the extent to which child care centers in South Carolina improved physical activity practices after a new policy took effect.

METHODS

In 2012, South Carolina adopted new mandatory physical activity standards within its child care quality enhancement program. This quasi-experimental study used North Carolina, a state not making policy changes, as the comparison. Participants were 34 child care centers in South Carolina and 30 centers in North Carolina. Researchers used the Environment and Policy Assessment and Observation (EPAO) tool to conduct center observations before and after policy implementation and then conducted repeated-measures linear regression with interaction between state and time for the Physical Activity Environment Total Score and the 8 subscale scores.

RESULTS

Compared with centers in North Carolina, EPAO subscale scores in South Carolina centers increased significantly for the Fixed Play Environment (P < .001) and Physical Activity Training and Education (P = .015). The state-by-time interaction of Physical Activity Environment Total Score approached statistical significance (P = .06).

CONCLUSIONS

Adoption of new physical activity standards in South Carolina child care centers was associated with improvements in practices aimed at increasing children's physical activity.

Policies for promotion of physical activity and prevention of obesity in adolescence

Obesity rates among children and adolescents in developed countries have increased dramatically since the 1970s. During that same period, numerous secular changes have combined to reduce the demand for physical activity in day-to-day life, and many barriers to physical activity are now evident. As a consequence, most children and adolescents do not meet the accepted public health guidelines for physical activity. Accordingly, public health interventions are needed to increase physical activity in adolescence. Such interventions, if successfully implemented, can be expected to improve fitness and health as well as reduce the prevalence of overweight and obesity in young people. Promotion of physical activity in populations of children and adolescents will require comprehensive strategic planning and adoption of new policies in multiple societal sectors. This paper highlights nine initiatives that can address the problem of physical activity in children. The initiatives are to: establish comprehensive school physical activity programming; demand high quality physical education; require physical activity in early child care and education; require physical activity in afterschool programs; create equity in community resources; activate youth sports programs; re-normalize active transport to school; institutionalize clinic-based physical activity assessment and counseling; and build activity-friendly homes. A case will be made for comprehensive national and international strategic planning aimed at effective and large-scale implementation of these initiatives and tactics.

Motivation and Behavioral Regulation of Physical Activity in Middle School Students

PURPOSE

This study aimed to examine whether intrinsic motivation and behavioral self-regulation are related to physical activity during middle school.

METHOD

Structural equation modeling was applied in cross-sectional and longitudinal tests of self-determination theory.

RESULTS

Consistent with theory, hypothesized relations among variables were supported. Integrated regulation and intrinsic motivation were most strongly correlated with moderate-to-vigorous physical activity measured by an accelerometer. Results were independent of a measure of biological maturity. Construct validity and equivalence of measures were confirmed longitudinally between the sixth and seventh grades and between boys and girls, non-Hispanic Black and White children and overweight and normal-weight students.

CONCLUSIONS

Measures of autonomous motivation (identified, integrated, and intrinsic) were more strongly related to physical activity in the seventh grade than measures of controlled motivation (external and introjected), implying that physical activity became more intrinsically motivating for some girls and boys as they moved through middle school. Nonetheless, change in introjected regulation was related to change in physical activity in the seventh grade, suggesting that internalized social pressures, which can be detrimental to sustained activity and well-being, also became motivating. These results encourage longer prospective studies during childhood and adolescence to clarify how controlled and autonomous motivations for physical activity develop and whether they respond to interventions designed to increase physical activity.

Classes of Physical Activity and Sedentary Behavior in 5th Grade Children

OBJECTIVES

We identified classes of physical activity (PA) and sedentary behaviors (SB) in 5th grade children, associated factors, and trajectories of change into 7th grade.

METHODS

This study included N = 495 children (221 boys, 274 girls) who participated in the Transitions and Activity Changes in Kids (TRACK) Study. PA was assessed objectively as well as by self-report. Children, parents, and school administrators completed surveys to assess related factors. Latent class analysis, growth modeling, and adjusted multinomial logistic regression procedures were used to classify children based on self-reported PA and SB and examine associated factors.

RESULTS

Three classes of behavior were identified: Class 1: Low PA/Low SB; Class 2: Moderate PA/ High SB; and Class 3: High PA/High SB (boys) or Class 3: High PA (girls). Class 3 children had higher levels of self-efficacy (boys), and enjoyment, parental support, and physical activity equipment at home (girls). Class 2 boys and Class 3 girls did not experience decline in PA (accelerometer) over time.

CONCLUSIONS

Self-efficacy (boys) and home environment (girls) may play a role in shaping patterns of PA in children. Findings may help to inform future interventions to encourage children to meet national PA guidelines.

Validation of Interviewer-Assisted Recall for Measuring Minutes of Moderate to Vigorous Physical Activity in Elementary School Children, Grades 3 and 5

OBJECTIVE

To test the validity of interviewer-administered recall for measuring moderate to vigorous physical activity (MVPA) in third- and fifth-grade children who reported physical activity (PA) only or both PA and diet, using a short (same-day recall in the afternoon) or long (previous-day recall in the morning) retention interval.

METHODS

Randomly selected children (n = 95) wore an accelerometer 1 day in school. Interviews occurred in the afternoon of the day on which the accelerometer was worn or on the next morning. Assignment to interview content was random. Spearman correlations were calculated between MVPA interview and MVPA accelerometer minutes.

RESULTS

The MVPA interview minutes were positively associated with the MVPA accelerometer minutes when the interview focused on PA only (r = .34; P = .02) but not when children recalled PA and diet (r = .12; P = .40). The MVPA interview minutes for the previous day was associated with the MVPA accelerometer minutes (r = .33; P = .02), but not for the same day (r = .17; P = .26).

CONCLUSIONS

A recall interview method that focuses solely on PA is a promising approach to assessing children's school-day PA.

Creating a Physical Activity Self-Report Form for Youth Using Rasch Methodology

Measurement of youth's physical activity levels is recommended to ensure that children are meeting recommended activity guidelines. This article describes the creation of an instrument to measure youth's levels of physical activity, where a strong test validation perspective (Benson, 1998) was followed to create the scale. The development process involved a mixed-method (qualitative followed by quantitative) framework. First, focus groups were conducted, where results informed item creation. Next, three alternative forms were created with different response formats to measure childrens' frequency of participation in various physical activities and intensity of participation. Lastly, a sample of over 500 middle school children was obtained, where three different response scales were investigated. The optimal scale considered measurement of physical activity using a three-point Likert frequency; intensity of activity participation did not strongly contribute to the measurement of children's activity levels. The final version form is thought to be acceptable for use with children in surveillance and large-group studies, as well as in smaller sample applications.