Sex differences in 3- to 5-year-old children's motor competence: A pooled cross-sectional analysis of 6241 children.

There is some, albeit inconsistent, evidence supporting sex differences in preschoolers' motor competence (MC), with these observations not uniform when analyzed by age, and cultural groups. Thus, this study examined sex differences across ages in 3- to 5-year-old children's MC. A cross-country pooled sample of 6241 children aged 3-5 years (49.6% girls) was assessed for MC using the Test of Gross Motor Development-2nd/3rd edition, and children were categorized into groups of age in months. Multiple linear regression models and predictive margins were calculated to explore how sex and age in months affect scores of MC (i.e., locomotor and ball skills), with adjustments for country and BMI. The Chow's Test was used to test for the presence of a structural break in the data. Significant differences in favor of girls were seen at 57-59 and 66-68 months of age for locomotor skills; boys performed better in ball skills in all age periods, except for 42-44 and 45-47 months of age. The higher marginal effects were observed for the period between 45-47 and 48-50 months for locomotor skills (F = 30.21; and F = 25.90 for girls and boys, respectively), and ball skills (F = 19.01; and F = 42.11 for girls and boys, respectively). A significantly positive break point was seen at 45-47 months, highlighting the age interval where children's MC drastically improved. The identification of this breakpoint provides an evidence-based metric for when we might expect MC to rapidly increase, and an indicator of early delay when change does not occur at that age.

The Influence of Motor Competence on Broader Aspects of Health: A Systematic Review of the Longitudinal Associations Between Motor Competence and Cognitive and Social-Emotional Outcomes.

BACKGROUND: Motor competence has important developmental associations with aspects of physical health, but there has been no synthesis of longitudinal associations with cognitive and social-emotional health. OBJECTIVES: The first aim was to present a conceptual model that positions motor competence as a mediator between physical activity and cognitive and social-emotional outcomes. The second aim was to synthesize the association of motor competence and cognitive and social-emotional development using longitudinal observational and experimental evidence, in particular to (i) identify the role of task, individual, and environmental characteristics in moderating the association between motor and cognitive and social-emotional outcomes and (ii) synthesize the strength of evidence pertaining to domain-specific relationships. METHODS: This systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO) and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews and meta-analyses. Five electronic databases (PubMed, Web of Science, Scopus, PsycINFO, and SPORTDiscus) were systematically searched. Following study screening and risk-of-bias assessment by two authors, 49 eligible studies were identified for inclusion and grouped by study design. Evidence for domain-specific paths between motor competence and cognitive and social-emotional outcomes was synthesized by calculating the significant analyses in the hypothesized direction, divided by the total number of analyses for that path. These percentages were then collated for each domain outcome. This collated influence was classified as either no association (0-33%), written as '0', or indeterminate/inconsistent (34-59%), written as '?' If there were fewer than three studies in the domain, the strength of evidence was classified as insufficient (I). RESULTS: Of the 49 studies, 35% were able to satisfy six or more of the seven risk-of-bias criteria. Longitudinal observational evidence about domain-specific and global associations of motor competence and cognitive and social-emotional development is indeterminate. The included studies also did not provide evidence for a consistent moderating role of age and sex. Some preliminary experimental evidence does support the role of motor competence in moderating the influence of cognitively enriched physical activity on cognitive outcomes, especially working memory and social-emotional skills. However, too few studies were appropriately designed to acknowledge the moderating role of contextual mechanisms. CONCLUSIONS: Between-study heterogeneity means it was not possible to identify definitive domain- and construct-specific relationships between motor competence and cognitive and social-emotional outcomes. To further develop our understanding, it is important that researchers acknowledge the complexity of these relationships within rigorous study designs.

Motor Competence and Body Mass Index in the Preschool Years: A Pooled Cross-Sectional Analysis of 5545 Children from Eight Countries.

BACKGROUND AND OBJECTIVE: One in five preschool children are overweight/obese, and increased weight status over time increases the risks of poorer future health. Motor skill competence may be a protective factor, giving children the ability to participate in health-enhancing physical activity. Yet, we do not know when the relationship between motor competence and weight status first emerges or whether it is evident across the body mass index (BMI) spectrum. This study examined the association between motor skill competence and BMI in a multi-country sample of 5545 preschoolers (54.36 ± 9.15 months of age; 50.5% boys) from eight countries. METHODS: Quantile regression analyses were used to explore the associations between motor skill competence (assessed using the Test of Gross Motor Development, Second/Third Edition) and quantiles of BMI (15th; 50th; 85th; and 97th percentiles), adjusted for sex, age in months, and country. RESULTS: Negative associations of locomotor skills, ball skills, and overall motor skill competence with BMI percentiles (p < 0.005) were seen, which became stronger at the higher end of the BMI distribution (97th percentile). Regardless of sex, for each raw score point increase in locomotor skills, ball skills, and overall motor skill competence scores, BMI is reduced by 8.9%, 6.8%, and 5.1%, respectively, for those preschoolers at the 97th BMI percentile onwards. CONCLUSIONS: Public health policies should position motor skill competence as critical for children's obesity prevention from early childhood onwards. Robust longitudinal and experimental designs are encouraged to explore a possible causal pathway between motor skill competence and BMI from early childhood.

Use of a Novel Theory-Based Pragmatic Tool to Evaluate the Quality of Instructor-Led Exercise Videos to Promote Youth Physical Activity at Home: Preliminary Findings.

BACKGROUND: Exercise videos that work to minimize cognitive load (the amount of information that working memory can hold at one time) are hypothesized to be more engaging, leading to increased PA participation. PURPOSE: To use a theory-based pragmatic tool to evaluate the cognitive load of instructor-led exercise videos associated with the Interrupting Prolonged Sitting with ACTivity (InPACT) program. METHODS: Exercise videos were created by physical education teachers and fitness professionals. An evaluation rubric was created to identify elements each video must contain to reduce cognitive load, which included three domains with four components each [technical (visual quality, audio quality, matching modality, signaling), content (instructional objective, met objective, call-to-action, bias), and instructional (learner engagement, content organization, segmenting, weeding)]. Each category was scored on a 3-point scale from 0 (absent) to 2 (proficient). A video scoring 20-24 points induced low cognitive load, 13-19 points induced moderate cognitive load, and less than 13 points induced high cognitive load. Three reviewers independently evaluated the videos and then agreed on scores and feedback. RESULTS: All 132 videos were evaluated. Mean video total score was 20.1 ± 0.7 points out of 24. Eighty-five percent of videos were rated low cognitive load, 15% were rated moderate cognitive load, and 0% were rated high cognitive load. The following components scored the highest: audio quality and matching modality. The following components scored the lowest: signaling and call-to-action. CONCLUSIONS: Understanding the use of a pragmatic tool is a first step in the evaluation of InPACT at Home exercise videos. Our preliminary findings suggest that the InPACT at Home videos had low cognitive load. If future research confirms our findings, using a more rigorous study design, then developing a collection of instructor-led exercise videos that induce low cognitive load may help to enhance youth physical activity participation in the home environment.

Sex Differences in Perceived Motor Competence After the Children's Health Activity Motor Program Intervention.

This study examined the effects of a motor-skill intervention on children's perceived motor competence (PMC; object control, locomotor, and combined [total]) and explored if effects differed between the sexes. Preschoolers (N = 274; 47.96 months) completed either a motor-skill intervention (the Children's Health Activity Motor Program [CHAMP]) or recess. PMC was measured with the Digital Scale of PMC before and after each condition. Controlling for pretest scores, recess girls had lower posttest object-control PMC scores than CHAMP boys, CHAMP girls, and recess boys (all p < .05). CHAMP children had significantly higher posttest locomotor and total PMC (all p < .001) compared with children who engaged in recess. CHAMP partially eliminates sex differences in PMC, particularly for object-control skills. Girls who participated in recess did not increase PMC like children in CHAMP and boys who engaged in outdoor recess.

An exploratory analysis examining differences in physical activity and motor competence in children with and without asthma: brief report.

OBJECTIVE: The purpose of this pilot study was to examine potential differences in motor competence (MC) and physical activity (PA) between children with and without asthma. METHODS: Thirty-seven children and adolescents completed the Exercises for a Healthy Asthma Lifestyle and Enjoyment study (46% with asthma, 51% female, 11.1 ± 0.4 years, and 46% White). Motor competence was assessed using the Movement Assessment Battery for Children 2nd edition (MABC-2). PA was assessed using accelerometry. RESULTS: Children with asthma had significantly lower MC in the domain of aiming and catching (with asthma: 8.2 ± 0.4 vs. without asthma: 9.9 ± 0.5; p = 0.03) and fewer daily minutes spent in moderate-to-vigorous PA (MVPA) (with asthma: 18.0 ± 2.3 min vs. without asthma: 27.2 ± 3.6 min; p = 0.047). There were no significant group differences in manual dexterity, balance, total MABC-2 score, or total daily PA (all ps > 0.05). CONCLUSIONS: This study provides confirmatory evidence that children with asthma display lower MC and spend less time in MVPA compared to children without asthma. Because MC is a prerequisite for engaging in PA, future research should seek to determine if the differences observed in MC contribute to disparities in MVPA observed in this clinical population.

Protocol for a cluster randomized clinical trial of a mastery-climate motor skills intervention, Children's Health Activity and Motor Program (CHAMP), on self-regulation in preschoolers.

INTRODUCTION: Self-regulation (SR) is critical to healthy development in children, and intervention approaches (i.e., professional training, classroom-based curricula, parent-focused intervention) have shown to support or enhance SR. However, to our knowledge, none have tested whether changes in children's SR across an intervention relate to changes in children's health behavior and outcomes. This study, the Promoting Activity and Trajectories of Health (PATH) for Children-SR Study uses a cluster-randomized control trial to examine the immediate effects of a mastery-climate motor skills intervention on SR. Secondly, this study examines the associations between changes in SR and changes in children's health behaviors (i.e., motor competence, physical activity, and perceived competence) and outcomes (i.e., body mass index and waist circumference) (ClinicalTrials.gov Identifier, NCT03189862). METHODS AND ANALYSIS: The PATH-SR study will be a cluster-randomized clinical trial. A total of 120 children between the ages of 3.5 to 5 years of age will be randomized to a mastery-climate motor skills intervention (n = 70) or control (n = 50) condition. SR will be assessed using measures that evaluate cognitive SR (cognitive flexibility and working memory), behavioral SR (behavioral inhibition), and emotional SR (emotional regulation). Health behaviors will be assessed with motor skills, physical activity, and perceived competence (motor and physical) and health outcomes will be waist circumference and body mass index. SR, health behaviors, and health outcomes will be assessed before and after the intervention (pre-test and post-test). Given the randomization design, 70 children in the intervention group and 50 in the control group, we have 80% power to detect an effect size of 0.52, at a Type I error level of 0.05. With the data collected, we will test the intervention effect on SR with a two-sample t-test comparing the intervention group and the control group. We will further evaluate the associations between changes in SR and changes in children's health behaviors and health outcomes, using mixed effect regression models, with a random effect to account for within-subject correlations. The PATH-SR study addresses gaps in pediatric exercise science and child development research. Findings hold the potential to help shape public health and educational policies and interventions that support healthy development during the early years. ETHICS AND DISSEMINATION: Ethical approval for this study was obtained through the Health Sciences and Behavioral Sciences Institutional Review Board, University of Michigan (HUM00133319). The PATH-SR study is funded by the National Institutes of Health Common Fund. Findings will be disseminated via print, online media, dissemination events and practitioner and/or research journals. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier, NCT03189862.

Mastery-oriented motor competence intervention improves behavioral but not cognitive self-regulation in head start preschoolers: Randomized controlled trial results.

Motor competence and self-regulation develop rapidly in early childhood; emerging work suggests motor competence interventions as a promising way to promote self-regulation (e.g., behavioral inhibition; cognitive flexibility) in young children. We tested the impact of a mastery-focused motor competence intervention (Children's Health Activity Motor Program [CHAMP])1 on behavioral and cognitive aspects of self-regulation among children attending Head Start. Grounded in Achievement Goal Theory, CHAMP encourages children's autonomy to navigate a mastery-oriented motor skill learning environment. Children (M age = 53.4 months, SD = 3.2) were cluster-randomized by classroom (6 per condition) to an intervention (n = 67) or control condition (n = 45). Behavioral self-regulation skills were assessed using the Head-Toes-Knees-Shoulders task (HTKS). Cognitive self-regulation skills were assessed using working memory and dimensional card-sorting executive function tasks. Random-effects hurdle models accounting for zero-inflated distributions indicated that children receiving CHAMP, versus not, were almost 3 times more likely to have non-zero HTKS scores at post-test; OR: 2.98 (CI 1.53, 5.81); however, there were no effects on any cognitive aspects of self-regulation (all p's > 0.05). Mastery climate motor competence interventions are an ecologically valid strategy that may have a greater impact on preschoolers' behavioral than cognitive aspects of self-regulation.

Performance Metrics From Product-Oriented Measures of Fundamental Motor Skills-A Comparison and Developmental Perspective.

This study (a) examined the associations among different performance metrics derived from different strategies (i.e., maximum and average scores) and trials from product-oriented measures of motor skills, and (b) explored how different performance metrics from product-oriented assessments of motor skills change in young children with typical development. Children (N = 279; 156 girls; Mage = 4.44 years) completed a battery of product-oriented assessments for throwing (in meters per second, five trials); kicking (in meters per second, five trials); jumping (in centimeters, five trials); running (in meters per second, two trials); and hopping (in meters per second, four trials-two preferred foot, two nonpreferred foot). A total of 36 performance metrics were derived-throw (n = 7), kick (n = 7), jump (n = 7), run (n = 4), and hop (n = 11). Intraclass correlations examined reliability among performance metrics for each skill; linear mixed models examined whether variations changed across early childhood. There was excellent reliability among all performance metrics for each skill (all ICC> .90). Linear mixed models revealed that children's motor performance improved for two metrics of the throw, five variations of the jump, and three metrics of the hop (all p <.05). Researchers should be aware that some performance metrics from product-oriented assessments (e.g., maximum and average of three or five trials) are highly related and change, whereas others do not.

Structured Observations of Child Behaviors during a Mastery-Motivational Climate Motor Skill Intervention: An Exploratory Study.

This exploratory study aimed to quantify children's engagement behaviors during a mastery-motivational climate intervention. We also completed an exploratory factor analysis to elucidate if child engagement changed across intervention sessions. METHOD: 35 children (17 boys; 18 girls) completed a 10-week mastery-motivational climate motor skill intervention. Engagement was operationalized as the time children were appropriately involved in the intervention and was assessed using momentary time sampling during the motor skill practice portion of the intervention. RESULTS: Overall, children were engaged 36% of the motor skills practice time (37% for boys; 36% for girls). Children who initially had below-average skills engaged for 36% (36% for boys; 35% for girls) of the motor skills practice time, and children who were average or above-average at the start of the intervention engaged in skill practice for 39% (39% for boys; 36% for girls). Differences in engagement in skill type (e.g., locomotor vs. ball skills) and trends over time were observed. CONCLUSION: These findings support that children engage in mastery-motivation climates, but the amount of participation may be influenced by individual factors of sex and initial skill level.

Weight stigma and physical activity avoidance among college-aged students.

This study explored cross-sectional associations between prior weight stigma experiences, physical activity (PA) intentions, behaviors, and the acute effects of a weight stigma exposure on PA intentions and behaviors among undergraduate students. Weight-stigma experiences and behavioral intentions were self-reported. Moderate-to-vigorous PA and total PA were assessed using accelerometry. Participants were randomized into two experimental conditions (a weight stigma or control condition) to assess the acute effects of a weight stigma exposure. Forty-nine students (81.6% female; 59.2% Non-Hispanic White; 19.6 ± 1.1 years of age; body mass index: 23.9 ± 4.0 kg/m2) completed the study. Prior weight stigma experiences were positively associated with PA avoidance (ß = 12.1 ± 2.7; p < .001) but were not associated with positive PA intentions or behaviors (ps > .05). There were no differences in positive PA intentions, PA avoidance, or PA behaviors across conditions (all ps > .05). Future studies should examine the long-term effects of weight stigma on PA avoidance and objectively measured PA in young college students.

Protocol for a multicenter-cluster randomized clinical trial of a motor skills intervention to promote physical activity and health in children: the CHAMP afterschool program study.

BACKGROUND: Promoting health-enhancing and sustainable physical activity levels across childhood and adolescence contribute to positive health outcomes as an adult. This study will aim to: a) examine the immediate (pre- to post-intervention) and sustained (1-year post-intervention follow-up) effects of the Children's Health Activity Motor Program-Afterschool Program (CHAMP-ASP) on physical activity, motor competence, and perceived motor competence relative to the comparison ASP, b) examine the immediate and sustained effects of CHAMP-ASP on secondary health outcomes, specifically health-related physical fitness (i.e., cardiorespiratory fitness, muscular strength, percent body fat) and weight status compared to children in the comparison ASP, and c) determine if perceived motor competence mediates the effect of CHAMP-ASP on moderate-to-vigorous physical activity. METHODS: This multicenter cluster randomized trial will be implemented by ASP staff and will be conducted in ASPs located in two city-based cohorts: East Lansing/Lansing and Ann Arbor/Ypsilanti, Michigan. Children (N = 264) who are K-2 graders will participate 35 min/day X 3 days/week for 19 weeks (1995 min) in their afterschool movement program (i.e., CHAMP-ASP vs. comparison). The research team will train ASP staff to implement the program, which will be delivered within the existing ASP offering. Measures of physical activity (accelerometer), motor competence (process and product measures of fundamental motor skills), health-related fitness, perceived motor competence, and anthropometry will be collected pre-, immediately post-, and one-year post-intervention. Random-effects models will be used to assess the clustered longitudinal effect of the intervention on outcome measures. DISCUSSION: The long-term goal is to provide a sustainable, ecologically-relevant, and evidence-based program during the early elementary years that can be delivered by ASP staff, is health-enhancing, and increases physical activity in children. Findings hold the potential to help shape public health and educational policies and interventions that support healthy development and active living during the early years. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT05342701 . ETHICS AND DISSEMINATION: Ethical approval was obtained through the Health Sciences and Behavioral Sciences IRB, University of Michigan (HUM00208311). The CHAMP-ASP study is funded by the National Institutes of Health. Findings will be disseminated via print, online media, dissemination events, and practitioner and/or research journals.

Relations among parent-reported physical activity and interoception in children.

BACKGROUND: Interoception is the sense of one's internal body and emotional state; it plays a critical role in guiding self-regulatory behaviors. Physical activity (PA) can support interoceptive processes, but limited research has examined the association in children. This study explored the relations among parent-reported PA and several interoceptive domains in children aged 3 - 10 years old. METHODS: Baseline data were analyzed from a cluster-randomized controlled study examining a yoga intervention (N = 122). Parents completed a questionnaire that included the Caregiver Questionnaire for Interoceptive Awareness, Second Edition (CQIA-2) and two measures of PA, the PROMIS Parent-Proxy Short Form (PROMIS-PA) and the adapted Burdette Proxy Report (aBPR-PA). Psychometrics of the CQIA-2 subscales were assessed and then used in subsequent analyses to examine the association between PA and interoceptive sensibility. RESULTS: Seventy percent of the surveys were completed by mothers (30% by fathers), and their children (56% female, Mage = 5.81 ± 1.7 years) were predominately white. Across all children, PA had a significant positive relationship with interoceptive domains related to emotion and physical energy (p < 0.01). Children who met the PROMIS-PA "good" cutoff had a clearer sense of emotion and physical energy (F(2,115) = 4.30, p = 0.016, R2 = 0.070), compared to children who did not. Children's age predicted interoceptive sensibility of illness and toileting needs (F(1,116) = 14.16, p < 0.001, R2 = 0.109). CONCLUSION: Children with higher PA levels were perceived to have better interoceptive sensibility of emotion and physical energy. Children's age was predictive of interoceptive domains representing the awareness of illness and toileting needs. Future work should consider incorporating direct measures of PA and child-reported interoceptive sensibility. A better understanding of their relationship will likely help guide the design of more effective interventions for health behavior development.

Variation and Predictors of Gross Motor Coordination Development in Azorean Children: A Quantile Regression Approach.

We investigated the development of gross motor coordination (GMC) as well as its predictors in school-aged Azorean children. The sample included 181 children (90 girls), followed consecutively for 4 years from 6 to 9 years of age. GMC was assessed with the Körperkoordinationstest für Kinder, and predictors included body mass index, standing long jump, 50-yard dash, and shuttle run. The changes in GMC and the effects of predictors were analyzed with mean-modeling as well as quantile regression. In the latter, we considered the following three quantiles (Q): Q20, Q50, and Q80 as markers of low, median, and high GMC levels, respectively. All analyses were conducted using R software and alpha was set at 5%. The GMC changes were curvilinear in both models, but the quantile approach showed a more encompassing picture of the changes across the three quantiles in both boys and girls with different rates of change. Further, the predictors had different effect sizes across the quantiles in both sexes, but in the mean-model their effects were constant. In conclusion, quantile regression provides more detailed information and permits a more thorough understanding of changes in GMC over time and the influence of putative predictors.

Considerations for a Social Media Physical Activity Program: Exploratory Study.

BACKGROUND: Social media may be a powerful platform to combat parents' and children's low physical activity levels. OBJECTIVE: This study surveyed parents' beliefs about physical activity in order to expand the extant literature concerning the interest in and the design of an effective and feasible social media physical activity (SMPA) program. METHODS: Primary caregivers (n=250; 215 [86%] mothers, 164 [65.6%] White) of children aged 6-12 years completed an online questionnaire. Interest was examined through responses on the questionnaire; beliefs (ie, perceptions, knowledge, and support) about physical activity were examined using Spearman correlations; and to support the SMPA program design, researchers examined a combination of multiple-choice and free-response questions. For the free-response questions, the researchers performed open coding related to perceived benefits, barriers, and motivators. RESULTS: Parent respondents (n=215, 86%) were interested in a SMPA program tailored for families. Regarding beliefs, parents exhibited a monotonic relationship between 2 questions related to perceptions of physical activity levels in their children (rs(250)=.310, P<.001), knowledge about physical activity and motor skills (rs(250)=.328, P<.001), and support of physical activity and motor skills (rs(250)=.385, P<.001). Parents perceived benefits of a SMPA program, highlighting family time and health. Barriers included time constraints, a lack of motivation, and environmental factors. CONCLUSIONS: Parents are interested in supporting healthy family behaviors using a SMPA program. An effective program should emphasize motor skill activities, be fun and family oriented, and incorporate incentives, goal setting, and advice and tips. SMPA also needs to address identified barriers, such as those regarding time and environment.

Psychological Responses to Intermittent Activities in Children With and Without Asthma.

PURPOSE: The purpose of this study was to examine the psychological responses to intermittent activities of varying intensities and types among children with and without asthma. METHODS: A total of 37 children and adolescents (51% male, aged 8-16 y, 54% nonwhite, and 54% without asthma) participated in this study. Participants completed 5 exercises in the same order: self-paced walking, resistance activities, dance video, gamified obstacle course, and step test. In-task mood was assessed using the Feeling Scale, in-task perceived exertion was assessed via the ratings of perceived exertion scale, and postactivity enjoyment was assessed using the Physical Activity Enjoyment Scale. RESULTS: There was a significant main effect of exercise type on mood (P < .001), ratings of perceived exertion (P < .001), and enjoyment (P < .002). There was not a significant main effect of asthma status on mood, ratings of perceived exertion, or enjoyment (Ps > .05). Children with asthma reported significantly lower in-task mood during the step exercise (P < .037) and reported significantly lower postactivity enjoyment after the walk and obstacle course exercises (Ps < .03). CONCLUSIONS: Regardless of differences by asthma status for in-task mood during the obstacle course and for postactivity enjoyment during the walk and step exercises, both children with and without asthma reported high in-task mood and postactivity enjoyment during all 5 exercises.

Are Gross Motor Skill Interventions an Equitable Replacement for Outdoor Free Play Regarding Children's Physical Activity?

PURPOSE: The purpose of this study was to determine if children engaged in equal amounts of physical activity during an established gross motor skill intervention (the Children's Health Activity Motor Program (CHAMP)) and outdoor free play. DESIGN: Cross-sectional study; sample: Ninety-nine children (Mage = 4.21, 51% boys) were randomly divided into two movement environments: CHAMP (n = 55) or control/outdoor free play (n = 44). MEASURES: Physical activity was assessed using GT3X+ Actigraph accelerometers worn on the waist across four mornings. Average physical activity across the four days during either CHAMP or outdoor free play was extracted and categorized as light, moderate, vigorous, or MVPA. Physical activity data were reduced in the Actilife software using the cutpoints from Evenson et al. ANALYSIS: A 2 (treatment) x 2 (sex) mixed measures ANOVA was used to compare the amount of time children spent in light, moderate, vigorous, and MVPA. RESULTS: There was a significant main effect for treatment for light PA (F(3,95) =13.60, P<.001, partial η2=.125), and post hoc t-tests support that children in the control/outdoor free play group engaged in more light PA compared with children in CHAMP (t95 = -3.75, P<.001). CONCLUSIONS: Results show that children in CHAMP engaged in less light PA but equal amounts of all other physical activity behaviors than their peers in outdoor free play.

Through the Looking Glass: A Systematic Review of Longitudinal Evidence, Providing New Insight for Motor Competence and Health.

INTRODUCTION: In 2008, a conceptual model explaining the role of motor competence (MC) in children's physical activity (PA), weight status, perceived MC and health-related fitness was published. OBJECTIVE: The purpose of the current review was to systematically compile mediation, longitudinal and experimental evidence in support of this conceptual model. METHODS: This systematic review (registered with PROSPERO on 28 April 2020) was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. Separate searches were undertaken for each pathway of interest (final search 8 November 2019) using CINAHL Complete, ERIC, Medline (OVID), PsycINFO, Web of Science Core Collection, Scopus and SportDiscus. Potential articles were initially identified through abstract and title checking (N = 585) then screened further and combined into one review (n = 152), with 43 articles identified for extraction. Studies needed to be original and peer reviewed, include typically developing children and adolescents first assessed between 2 and 18 years and objective assessment of gross MC and at least one other variable (i.e., PA, weight status, perceived MC, health-related fitness). PA included sport participation, but sport-specific samples were excluded. Longitudinal or experimental designs and cross-sectional mediated models were sought. Strength of evidence was calculated for each pathway in both directions for each domain (i.e., skill composite, object control and locomotor/coordination/stability) by dividing the proportion of studies indicating a significantly positive pathway in the hypothesised direction by the total associations examined for that pathway. Classifications were no association (0-33%), indeterminate/inconsistent (34-59%), or a positive '+' or negative ' - ' association (≥ 60%). The latter category was classified as strong evidence (i.e., ++or --) when four or more studies found an association. If the total number of studies in a domain of interest was three or fewer, this was considered insufficient evidence to make a determination. RESULTS: There was strong evidence in both directions for a negative association between MC and weight status. There was strong positive evidence for a pathway from MC to fitness and indeterminate evidence for the reverse. There was indeterminate evidence for a pathway from MC to PA and no evidence for the reverse pathway. There was insufficient evidence for the MC to perceived MC pathway. There was strong positive evidence for the fitness-mediated MC/PA pathway in both directions. There was indeterminate evidence for the perceived MC-mediated pathway from PA to MC and no evidence for the reverse. CONCLUSION: Bidirectional longitudinal associations of MC with weight status are consistent with the model authored by Stodden et al. (Quest 2008;60(2):290-306, 2008). However, to test the whole model, the field needs robust longitudinal studies across childhood and adolescence that include all variables in the model, have multiple time points and account for potential confounding factors. Furthermore, experimental studies that examine change in MC relative to change in the other constructs are needed. TRIAL REGISTRATIONS: PROSPERO ID# CRD42020155799.

Racial differences in psychological stress and insulin sensitivity in non-Hispanic Black and White adolescents with overweight/obesity.

INTRODUCTION: Racial differences in type 2 diabetes risk persist among non-Hispanic Black and non-Hispanic White adolescents with overweight/obesity; however, the role of psychological stress in this disparity is less clear. PURPOSE: To examine racial differences in the association between psychological stress, insulin sensitivity (Si), acute insulin response to glucose (AIRg), and disposition index (DI) among non-Hispanic Black and non-Hispanic White adolescents with overweight/obesity. METHODS: Ninety-six adolescents (60% female; 51% non-Hispanic Black; 16.6 ± 1.8 years of age) with overweight/obesity (BMI percentile ≥ 85th percentile) were included in this analysis. Psychological stress was assessed using the 14-item Perceived Stress Scale. Glucose and insulin data from an intravenous glucose tolerance test was modeled to obtain Si, AIRg, and DI. Multivariable linear regression models were used to examine the association between race, psychological stress and metabolic outcomes (Si, AIRg, and DI). RESULTS: Race was a significant predictor of log-AIRg and log-DI (ps < 0.05) independent of all covariates in the main effect models. Lower Si (pinteraction = 0.014) and DI (pinteraction = 0.012) was also observed among Black adolescents who reported higher stress levels, whereas higher Si and DI was observed among non-Hispanic White adolescents reporting higher stress in the race interaction models. Race however, did not moderate the association between psychological stress and AIRg (p > 0.05), nor was stress associated with Si, AIRg, or DI ("p" "s" > 0.05) across all other models. CONCLUSIONS: Psychological stress may play an important and distinct role in shaping racial differences in type 2 diabetes risk among adolescents with overweight/obesity. Additional research is needed to understand the long-term effects of psychological stress on metabolic health among non-Hispanic Black and non-Hispanic White adolescents with overweight/obesity.