Rugby Fans in Training New Zealand (RUFIT NZ): a randomized controlled trial to assess the effectiveness of a healthy lifestyle program for overweight men delivered through professional rugby clubs.

BACKGROUND: A healthy lifestyle program that appeals to, and supports, overweight and obese New Zealand (NZ) European, Maori (indigenous) and Pasifika men to achieve weight loss is urgently needed. A pilot program inspired by the successful Football Fans in Training program but delivered via professional rugby clubs in NZ (n = 96) was shown to be effective in weight loss, adherence to healthy lifestyle behaviors, and cardiorespiratory fitness in overweight and obese men. A full effectiveness trial is now needed. AIMS: To determine the effectiveness and cost effectiveness of Rugby Fans In Training-NZ (RUFIT-NZ) on weight loss, fitness, blood pressure, lifestyle change, and health related quality of life (HRQoL) at 12- and 52-weeks. METHODS: We conducted a pragmatic, two-arm, multi-center, randomized controlled trial in NZ with 378 (target 308) overweight and obese men aged 30-65 years, randomized to an intervention group or wait-list control group. The 12-week RUFIT-NZ program was a gender-sensitised, healthy lifestyle intervention delivered through professional rugby clubs. Each intervention session included: i) a 1-h workshop-based education component focused on nutrition, physical activity, sleep, sedentary behavior, and learning evidence-based behavior change strategies for sustaining a healthier lifestyle; and 2) a 1-h group-based, but individually tailored, exercise training session. The control group were offered RUFIT-NZ after 52-weeks. The primary outcome was change in body weight from baseline to 52-weeks. Secondary outcomes included change in body weight at 12-weeks, waist circumference, blood pressure, fitness (cardiorespiratory and musculoskeletal), lifestyle behaviors (leisure-time physical activity, sleep, smoking status, and alcohol and dietary quality), and health-related quality of life at 12- and 52-weeks. RESULTS: Our final analysis included 200 participants (intervention n = 103; control n = 97) who were able to complete the RUFIT-NZ intervention prior to COVID-19 restrictions. At 52-weeks, the adjusted mean group difference in weight change (primary outcome) was -2.77 kg (95% CI -4.92 to -0.61), which favored the intervention group. The intervention also resulted in favorable significant differences in weight change and fruit and vegetable consumption at 12-weeks; and waist circumference, fitness outcomes, physical activity levels, and health-related quality of life at both 12 and 52 weeks. No significant intervention effects were observed for blood pressure, or sleep. Incremental cost-effective ratios estimated were $259 per kg lost, or $40,269 per quality adjusted life year (QALY) gained. CONCLUSION: RUFIT-NZ resulted in sustained positive changes in weight, waist circumference, physical fitness, self-reported physical activity, selected dietary outcomes, and health-related quality of life in overweight/obese men. As such, the program should be recommended for sustained delivery beyond this trial, involving other rugby clubs across NZ. TRIAL REGISTRATION: Australia New Zealand Clinical Trials Registry, ACTRN12619000069156. Registered 18 January 2019, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=376740 Universal Trial Number, U1111-1245-0645.

Effects of physical education interventions on cognition and academic performance outcomes in children and adolescents: a systematic review and meta-analysis.

OBJECTIVE: To determine the effects of interventions aimed at optimising the quantity and quality of physical education (PE) on cognition and academic performance in children and adolescents. DESIGN: A systematic review and meta-analysis. DATA SOURCES: Studies from electronic databases from inception to 3 January 2021 were identified. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Experimental studies that assessed the effect of quantity-based (ie, increasing the amount of curriculum time allocated to PE) or quality-based (ie, increasing students' participation in physical activity during PE) PE interventions, or both, on changes in cognition and/or academic performance in youth (aged 5-18 years) were included. RESULTS: 19 trials comprising 8676 youth (46.5% girls) were included. Individual quality-based PE interventions increased cognition performance (Hedges' g=0.38, 95% CI 0.15 to 0.60; I 2=83.70%), mainly in primary education settings (g=0.48, 95% CI 0.07 to 0.89; I 2=90.43%). Academic performance, principally mathematics-related skills, was also increased by quality-based PE interventions (g=0.15, 95% CI 0.06 to 0.24; I 2=41.75%). Among these interventions, teaching strategies favoured similar results, but without heterogeneity in the results (g=0.12, 95% CI 0.05 to 0.18; I 2=0%). In contrast, quantity-based PE interventions had a very small and non-significant effect on academic performance (g=0.09, 95% CI -0.05 to 0.24; Q=11.65; I 2=48.48%). Finally, there were no differences between the three PE interventions (ie, quantity, quality, and combined PE interventions) in regard to academic performance. CONCLUSION: Improving the quality of PE classes may improve students' cognition and academic performance in children and adolescents. Importantly, allocating more time for PE does not seem to compromise this performance.

School-based interventions modestly increase physical activity and cardiorespiratory fitness but are least effective for youth who need them most: an individual participant pooled analysis of 20 controlled trials.

OBJECTIVES: To determine if subpopulations of students benefit equally from school-based physical activity interventions in terms of cardiorespiratory fitness and physical activity. To examine if physical activity intensity mediates improvements in cardiorespiratory fitness. DESIGN: Pooled analysis of individual participant data from controlled trials that assessed the impact of school-based physical activity interventions on cardiorespiratory fitness and device-measured physical activity. PARTICIPANTS: Data for 6621 children and adolescents aged 4-18 years from 20 trials were included. MAIN OUTCOME MEASURES: Peak oxygen consumption (VO2Peak mL/kg/min) and minutes of moderate and vigorous physical activity. RESULTS: Interventions modestly improved students' cardiorespiratory fitness by 0.47 mL/kg/min (95% CI 0.33 to 0.61), but the effects were not distributed equally across subpopulations. Girls and older students benefited less than boys and younger students, respectively. Students with lower levels of initial fitness, and those with higher levels of baseline physical activity benefitted more than those who were initially fitter and less active, respectively. Interventions had a modest positive effect on physical activity with approximately one additional minute per day of both moderate and vigorous physical activity. Changes in vigorous, but not moderate intensity, physical activity explained a small amount (~5%) of the intervention effect on cardiorespiratory fitness. CONCLUSIONS: Future interventions should include targeted strategies to address the needs of girls and older students. Interventions may also be improved by promoting more vigorous intensity physical activity. Interventions could mitigate declining youth cardiorespiratory fitness, increase physical activity and promote cardiovascular health if they can be delivered equitably and their effects sustained at the population level.

Associations of object control motor skill proficiency, game play competence, physical activity and cardiorespiratory fitness among primary school children.

This study investigated if object control relates to children's game play competence, and examined these competencies as correlates of physical activity and cardiorespiratory fitness. Game play (Game Performance Assessment Instrument), object control (The Test Gross Motor Development-3), moderate-to-vigorous physical activity (Accelerometry), and cardiorespiratory fitness (20-metre shuttle) assessments were completed for 107 children (57% Female, 43% Male) aged 9-12 years (M 10.53, SD 0.65). Two-level regression of object control on game play competence, and object control and game play competence on physical activity and cardiorespiratory fitness assessed associations. Object control competence was positively associated with game play competence (Std. B = 0.25, t (104.77) = 2.38, p = 0.001). Game play competence (Std. B = 0.33, t (99.81) = 5.21, p < 0.000) was more strongly associated with moderate-to-vigorous physical activity than object control competence (Std. B = 0.20, t (106.93) = 2.96, p = 0.003). Likewise, game competence (Std. B = 0.39, t (104.41) = 4.36, p < 0.000) was more strongly associated with cardiorespiratory fitness than object control competence (Std. B = 0.22, t (106.69) = 2.63, p = 0.002). Object control and game competence are both important as correlates of physical activity and cardiorespiratory fitness in children.

Associations between fundamental movement skill competence, physical activity and psycho-social determinants in Hong Kong Chinese children.

Associations between fundamental movement skills (FMS), perceived competence, enjoyment and physical activity (PA) have not been widely investigated among Chinese school children. We hypothesised that FMS would be directly related to self-reported and objectively measured PA, and indirectly related to these outcomes via perceived physical and movement skill competence, and enjoyment. Participants were 763 primary school children (age = 9.3 ± 1.7 years; 474 girls) across grades. FMS were measured for a subsample (n = 603) using Test of Gross Motor Development-2. PA using accelerometers was obtained from this subgroup (n = 238). All participating children completed a questionnaire measuring their PA participation, enjoyment, and perceived physical and movement skill competence. Structural equation modelling revealed positive associations between locomotor skills and perceived movement skill competence (ß = .11, 95% CI [.001, .22]), and between perceived movement skill competence and objectively measured PA (ß = .59, 95% CI [.04, 1.14]). Perceived physical competence and enjoyment mediated the association between locomotor skills and self-reported PA (ß = .08, 95% CI [.02, .12]), but not objectively measured PA. Given inconsistent findings for subjective and objective measures of PA, further mediation analyses of the association between FMS and PA may be warranted.

Improving health-related fitness in adolescents: the CrossFit Teens™ randomised controlled trial.

The aim of this study was to evaluate the preliminary efficacy and feasibility of the CrossFit Teens™ resistance training programme for improving health-related fitness and resistance training skill competency in adolescents. This assessor-blinded randomised controlled trial was conducted in one secondary school in the Hunter Region, Australia, from July to September 2013. Ninety-six (96) students (age = 15.4 (.5) years, 51.5% female) were randomised into intervention (n = 51) or control (n = 45) conditions for 8-weeks (60 min twice per week). Waist circumference, body mass index (BMI), BMI-Z score (primary outcomes), cardiorespiratory fitness (shuttle run test), muscular fitness (standing jump, push-up, handgrip, curl-up test), flexibility (sit and reach) and resistance training skill competency were measured at baseline and immediate post-intervention. Feasibility measures of recruitment, retention, adherence and satisfaction were assessed. Significant group-by-time intervention effects were found for waist circumference [-3.1 cm, P < 0.001], BMI [-1.38 kg · m(‒)(2), P < 0.001], BMI-Z [-0.5 z-scores, P < 0.001], sit and reach [+3.0 cm, P < 0.001], standing jump [+0.1 m, P = 0.021] and shuttle run [+10.3 laps, P = 0.019]. Retention rate was 82.3%. All programme sessions were delivered and participants' mean satisfaction scores ranged from 4.2 to 4.6 out of 5. The findings demonstrate that CrossFit Teens™ is a feasible and efficacious programme for improving health-related fitness in adolescents.

The PLUNGE randomized controlled trial: evaluation of a games-based physical activity professional learning program in primary school physical education.

OBJECTIVE: To evaluate the efficacy of the Professional Learning for Understanding Games Education (PLUNGE) program on fundamental movement skills (FMS), in-class physical activity and perceived sporting competence. METHODS: A cluster-randomized controlled trial involving one year six class each from seven primary schools (n=168; mean age=11.2 years, SD=1.0) in the Hunter Region, NSW, Australia. In September (2013) participants were randomized by school into the PLUNGE intervention (n=97 students) or the 7-week wait-list control (n=71) condition. PLUNGE involved the use of Game Centered curriculum delivered via an in-class teacher mentoring program. Students were assessed at baseline and 8-week follow-up for three object control FMS (Test of Gross Motor Development 2), in-class physical activity (pedometer steps/min) and perceived sporting competence (Self-perception Profile for Children). RESULTS: Linear mixed models revealed significant group-by-time intervention effects (all p<0.05) for object control competency (effect size: d=0.9), and in-class pedometer steps/min (d=1.0). No significant intervention effects (p>0.05) were observed for perceived sporting competence. CONCLUSIONS: The PLUNGE intervention simultaneously improved object control FMS proficiency and in-class PA in stage three students.

Adolescent pedometer protocols: examining reactivity, tampering and participants' perceptions.

The aim of this study was to investigate adolescents' potential reactivity and tampering while wearing pedometers by comparing different monitoring protocols to accelerometer output. The sample included adolescents (N = 123, age range = 14-15 years) from three secondary schools in New South Wales, Australia. Schools were randomised to one of the three pedometer monitoring protocols: (i) daily sealed (DS) pedometer group, (ii) unsealed (US) pedometer group or (iii) weekly sealed (WS) pedometer group. Participants wore pedometers (Yamax Digi-Walker CW700, Yamax Corporation, Kumamoto City, Japan) and accelerometers (Actigraph GT3X+, Pensacola, USA) simultaneously for seven days. Repeated measures analysis of variance was used to examine potential reactivity. Bivariate correlations between step counts and accelerometer output were calculated to explore potential tampering. The correlation between accelerometer output and pedometer steps/day was strongest among participants in the WS group (r = 0.82, P ≤ 0.001), compared to the US (r = 0.63, P ≤ 0.001) and DS (r = 0.16, P = 0.324) groups. The DS (P ≤ 0.001) and US (P = 0.003), but not the WS (P = 0.891), groups showed evidence of reactivity. The results suggest that reactivity and tampering does occur in adolescents and contrary to existing research, pedometer monitoring protocols may influence participant behaviour.

Associations Between Motor Competence and Executive Functions in Children and Adolescents: A Systematic Review and Meta-analysis.

BACKGROUND: Motor competence and executive functions co-develop throughout childhood and adolescence, and there is emerging evidence that improvements in motor competence may have cognitive benefits in these populations. There is a need to provide a quantitative synthesis of the cross-sectional, longitudinal and experimental studies that have examined the association between motor competence and executive functions in school-aged youth. OBJECTIVES: The primary aim of our systematic review was to synthesise evidence of the association between motor competence and executive functions in school-aged children and adolescents (5-18 years). Our secondary aim was to examine key moderators of this association. METHODS: We searched the PubMed, PsycINFO, Scopus, Ovid MEDLINE, SPORTDiscus and EMBASE databases from inception up to 27 June 2023. We included cross-sectional, longitudinal and experimental studies that assessed the association between motor competence (e.g., general motor competence, locomotor skills, object control skills and stability skills) and executive functions (e.g., general executive functions, inhibition, working memory and cognitive flexibility) in children and adolescents aged 5-18 years. RESULTS: In total, 12,117 records were screened for eligibility, and 44 studies were included. From the 44 included studies, we meta-analysed 37 studies with 251 effect sizes using a structural equation modelling approach in the statistical program R. We found a small positive association (r = 0.18, [95% confidence interval (CI) 0.13-0.22]) between motor competence and executive functions. The positive associations were observed in cross-sectional (r = 0.17, [95% CI 0.13-0.22]), longitudinal (r = 0.15, [95% CI 0.03-0.28]) and experimental studies (r = 0.25, [95% CI 0.01-0.45]). We also found that general motor competence (r = 0.25, [95% CI 0.18-0.33]), locomotor (r = 0.15, [95% CI 0.09-0.21]), object control (r = 0.14, [95% CI 0.08-0.20]) and stability (r = 0.14, [95% CI 0.08-0.20]) skills were associated with executive functions. We did not find any moderating effects for participants' age on the associations between motor competence and executive functions. CONCLUSIONS: Our findings suggest a small-to-moderate positive association between motor competence and executive functions in children and adolescents. The small number of experimental studies included in this review support the assertion that interventions targeting children's motor competence may be a promising strategy to improve their executive functions; however, more research is needed to confirm these findings. Future studies should explore the underlying mechanisms linking motor competence and executive functions as their comprehension may be used to optimise future intervention design and delivery. PROSPERO REGISTRATION: CRD42021285134.

Rethinking children's physical activity interventions at school: A new context-specific approach.

Physical activity is important for children's health. However, evidence suggests that many children and adults do not meet international physical activity recommendations. Current school-based interventions have had limited effect on physical activity and alternative approaches are needed. Context, which includes school setting, ethos, staff, and sociodemographic factors, is a key and largely ignored contributing factor to school-based physical activity intervention effectiveness, impacting in several interacting ways. Conceptualization: Current programs focus on tightly-constructed content that ignores the context in which the program will be delivered, thereby limiting effectiveness. We propose a move away from uniform interventions that maximize internal validity toward a flexible approach that enables schools to tailor content to their specific context. Evaluation designs: Evaluation of context-specific interventions should explicitly consider context. This is challenging in cluster randomized controlled trial designs. Thus, alternative designs such as natural experiment and stepped-wedge designs warrant further consideration. Primary outcome: A collective focus on average minutes of moderate-to-vigorous intensity physical activity may not always be the most appropriate choice. A wider range of outcomes may improve children's physical activity and health in the long-term. In this paper, we argue that greater consideration of school context is key in the design and analysis of school-based physical activity interventions and may help overcome existing limitations in the design of effective interventions and thus progress the field. While this focus on context-specific interventions and evaluation is untested, we hope to stimulate debate of the key issues to improve future physical activity intervention development and implementation.

Effects of Resistance Training on Academic Outcomes in School-Aged Youth: A Systematic Review and Meta-Analysis.

BACKGROUND: The primary aim of our systematic review and meta-analysis was to investigate the effect of resistance training on academic outcomes in school-aged youth. METHODS: We conducted a systematic search of six electronic databases (CINAHL Complete, PsycINFO, SCOPUS, Ovid MEDLINE, SPORTDiscus and EMBASE) with no date restrictions. Studies were eligible if they: (a) included school-aged youth (5-18 years), and (b) examined the effect of resistance training on academic outcomes (i.e., cognitive function, academic achievement, and/or on-task behaviour in the classroom). Risk of bias was assessed using the appropriate Cochrane Risk of Bias Tools, funnel plots and Egger's regression asymmetry tests. A structural equation modelling approach was used to conduct the meta-analysis. RESULTS: Fifty-three studies were included in our systematic review. Participation in resistance training (ten studies with 53 effect sizes) had a small positive effect on the overall cognitive, academic and on-task behaviours in school-aged youth (standardized mean difference (SMD) 0.19, 95% confidence interval (CI) 0.05-0.32). Resistance training was more effective (SMD 0.26, 95% CI 0.10-0.42) than concurrent training, i.e., the combination of resistance training and aerobic training (SMD 0.11, 95% CI - 0.05-0.28). An additional 43 studies (including 211 effect sizes) examined the association between muscular fitness and cognition or academic achievement, also yielding a positive relationship (SMD 0.13, 95% CI 0.10-0.16). CONCLUSION: This review provides preliminary evidence that resistance training may improve cognitive function, academic performance, and on-task behaviours in school-aged youth. PROSPERO REGISTRATION: CRD42020175695.

Mechanisms Linking Physical Activity with Psychiatric Symptoms Across the Lifespan: A Systematic Review.

BACKGROUND: Physical activity has been suggested as a protective factor against psychiatric symptoms. While numerous studies have focused on the magnitude of physical activity's effect on psychiatric symptoms, few have examined the potential mechanisms. OBJECTIVE: The current review aimed to synthesize scientific evidence of the mechanisms through which physical activity might reduce psychiatric symptoms across the lifespan. METHODS: We included articles that were published before March 2022 from five electronic databases (MEDLINE, Web of Science, PsycINFO, Embase, and Cochrane). A qualitative synthesis of studies was conducted. The risk of bias assessment was performed using The Joanna Briggs Institute Critical Appraisal Tool for Systematic Reviews. Studies were included if they explored the possible mechanisms through which physical activity influences psychiatric symptoms (i.e., internalizing and externalizing symptoms) across the lifespan. RESULTS: A total of 22 articles were included (three randomized controlled trials, four non-randomized controlled trials, three prospective longitudinal studies, and 12 cross-sectional studies). Overall, most of the studies focused on children, adolescents, and young adults. Our findings showed that self-esteem, self-concept, and self-efficacy were the only consistent paths through which physical activity influences psychiatric symptoms (specifically depressive and anxiety symptoms) across the lifespan. There were insufficient studies to determine the role of neurobiological mechanisms. CONCLUSIONS: Overall, future physical activity interventions with the purpose of improving mental health should consider these mechanisms (self-esteem, self-concept, self-efficacy) to develop more effective interventions. CLINICAL TRIAL REGISTRATION: The protocol of this study was registered in the PROSPERO database (registration number CRD42021239440) and published in April 2022.

Exercise as therapy for neurodevelopmental and cognitive dysfunction in people with a Fontan circulation: A narrative review.

People with a Fontan circulation are at risk of neurodevelopmental delay and disability, and cognitive dysfunction, that has significant implications for academic and occupational attainment, psychosocial functioning, and overall quality of life. Interventions for improving these outcomes are lacking. This review article discusses current intervention practices and explores the evidence supporting exercise as a potential intervention for improving cognitive functioning in people living with a Fontan circulation. Proposed pathophysiological mechanisms underpinning these associations are discussed in the context of Fontan physiology and avenues for future research are recommended.

Supporting adolescents' participation in muscle-strengthening physical activity: protocol for the 'Resistance Training for Teens' (RT4T) hybrid type III implementation-effectiveness trial.

INTRODUCTION: In Australia, only 22% of male and 8% of female adolescents meet the muscle-strengthening physical activity guidelines, and few school-based interventions support participation in resistance training (RT). After promising findings from our effectiveness trial, we conducted a state-wide dissemination of the 'Resistance Training for Teens' (RT4T) intervention from 2015 to 2020. Despite high estimated reach, we found considerable variability in programme delivery and teachers reported numerous barriers to implementation. Supporting schools when they first adopt evidence-based programmes may strengthen programme fidelity, sustainability, and by extension, programme impact. However, the most effective implementation support model for RT4T is unclear. OBJECTIVE: To compare the effects of three implementation support models on the reach (primary outcome), dose delivered, fidelity, sustainability, impact and cost of RT4T. METHODS AND ANALYSIS: We will conduct a hybrid type III implementation-effectiveness trial involving grade 9 and 10 (aged 14-16 years) students from 90 secondary schools in New South Wales (NSW), Australia. Schools will be recruited across one cohort in 2023, stratified by school type, socioeconomic status and location, and randomised in a 1:1:1 ratio to receive one of the following levels of implementation support: (1) 'low' (training and resources), (2) 'moderate' (training and resources+external support) or 'high' (training and resources+external support+equipment). Training includes a teacher workshop related to RT4T programme content (theory and practical sessions) and the related resources. Additional support will be provided by trained project officers from five local health districts. Equipment will consist of a pack of semiportable RT equipment (ie, weighted bars, dumbbells, resistance bands and inverted pull up bar stands) valued at ~$A1000 per school. Study outcomes will be assessed at baseline (T0), 6 months (T1) and 18 months (T2). A range of quantitative (teacher logs, observations and teacher surveys) and qualitative (semistructured interviews with teachers) methods will be used to assess primary (reach) and secondary outcomes (dose delivered, fidelity, sustainability, impact and cost of RT4T). Quantitative analyses will use logistic mixed models for dichotomous outcomes, and ordinal or linear mixed effects regression models for continuous outcomes, with alpha levels set at p<0.025 for the outcomes and cost comparisons of the moderate and high support arms against the low support arm. ETHICS AND DISSEMINATION: Ethics approval has been obtained from the University of Newcastle (H-2021-0418), the NSW Department of Education (SERAP:2022215), Hunter New England Human Research Ethics Committee (2023/ETH00052) and the Catholic Schools Office. The design, conduct and reporting will adhere to the Consolidated Standards of Reporting Trials statement, the Standards for Reporting Implementation Studies statement and the Template for Intervention Description and Replication checklist. Findings will be published in open access peer-reviewed journals, key stakeholders will be provided with a detailed report. We will support ongoing dissemination of RT4T in Australian schools via professional learning for teachers. TRIAL REGISTRATION NUMBER: ACTRN12622000861752.

Effect of high-intensity interval training on hippocampal metabolism in older adolescents.

Although well-evidenced in older adults, the effects of exercise on the hippocampus in youth are relatively unknown. This study examined the impact of a 6-month school-based physical activity intervention on hippocampal metabolism in adolescents using magnetic resonance spectroscopy. A subset of lower fit older adolescents [N = 56, 61% female, 16.1 ± 0.4 years] was included from four secondary schools (10 classes) in New South Wales, Australia, who were participating in a larger cluster randomized controlled trial. Participants were randomized to the Burn 2 Learn (B2L) intervention (five classes, 30 participants) or a control group (five classes, 26 participants). Changes in hippocampal metabolism were assessed using linear mixed models adjusted for clustering at the class level. We observed group-by-time effects for the B2L intervention on N-acetylaspartate (NAA) (+2.66 mmol/L, 95% CI 0.20 to 5.11, d = 0.66) and glutamate+glutamine (Glx) (+3.38 mmol/L, 95% CI 0.34 to 6.42, d = 0.67) in the left hippocampus. Increases in left hippocampal NAA and Glx concentrations were associated with improvements in cardiorespiratory fitness (NAA: rs  = 0.52, p = .016; Glx: rs  = 0.57, p = .007), lower body muscular fitness (NAA: rs  = 0.49, p = .018; Glx: rs  = 0.59, p = .003), and working memory (NAA: rs  = 0.42, p = .032; Glx: rs  = 0.43, p = .028) in the intervention group. Our findings suggest physical activity may improve hippocampal metabolism in lower fit older adolescents with implications for working memory. Further studies involving larger samples are needed to replicate our findings.

Mechanisms linking physical activity with psychiatric symptoms across the lifespan: a protocol for a systematic review.

INTRODUCTION: Persistent psychiatric symptomatology during childhood and adolescence predicts vulnerability to experience mental illness in adulthood. Physical activity is well-known to provide mental health benefits across the lifespan. However, the underlying mechanisms linking physical activity and psychiatric symptoms remain underexplored. In this context, we aim to systematically synthesise evidence focused on the mechanisms through which physical activity might reduce psychiatric symptoms across all ages. METHODS AND ANALYSIS: With the aid of a biomedical information specialist, we will develop a systematic search strategy based on the predetermined research question in the following electronic databases: MEDLINE, Embase, Web of Science, Cochrane and PsycINFO. Two independent reviewers will screen and select studies, extract data and assess the risk of bias. In case of inability to reach a consensus, a third person will be consulted. We will not apply any language restriction, and we will perform a qualitative synthesis of our findings as we anticipate that studies are scarce and heterogeneous. ETHICS AND DISSEMINATION: Only data that have already been published will be included. Then, ethical approval is not required. Findings will be published in a peer-reviewed journal and presented at conferences. Additionally, we will communicate our findings to healthcare providers and other sections of society (eg, through regular channels, including social media). PROSPERO REGISTRATION NUMBER: CRD42021239440.

Skill Acquisition Methods Fostering Physical Literacy in Early-Physical Education (SAMPLE-PE): Rationale and Study Protocol for a Cluster Randomized Controlled Trial in 5-6-Year-Old Children From Deprived Areas of North West England.

BACKGROUND: There is a need for interdisciplinary research to better understand how pedagogical approaches in primary physical education (PE) can support the linked development of physical, cognitive and affective aspects of physical literacy and physical activity behaviors in young children living in deprived areas. The Skill Acquisition Methods fostering Physical Literacy in Early-Physical Education (SAMPLE-PE) study aims to examine the efficacy of two different pedagogies for PE, underpinned by theories of motor learning, to foster physical literacy. METHODS: SAMPLE-PE will be evaluated through a cluster-randomized controlled trial targeting 5-6 year old children from schools located in areas of high deprivation in Merseyside, North-West England. Schools will be randomly allocated to one of three conditions: Linear Pedagogy, Non-linear Pedagogy, or Control. Non-linear and Linear Pedagogy intervention primary schools will receive a PE curriculum delivered by trained coaches over 15 weeks, while control schools will follow their usual practice. Data will be collected at baseline (T0), immediately post-intervention (T1), and 6 months after the intervention has finished (T2). Children's movement competence is the primary outcome in this trial. Secondary outcomes include physical activity, perceived competence, motivation, executive functions, and self-regulation. An extensive process evaluation will also examine implementation factors such as intervention context, reach, dose, fidelity and acceptability. DISCUSSION: The SAMPLE-PE project will enable better understanding surrounding how to operationalise physical literacy through enrichment of PE practices in early PE. The study will provide robust scientific evidence regarding the efficacy of underpinning PE pedagogy with theories of motor learning to promote the development of physical literacy. TRIAL REGISTRATION: Retrospectively registered on 5th September 2018 at ClinicalTrials.gov, a resource provided by the U.S. National Library of Medicine (Identifier: NCT03551366).

Social, psychological and behavioural correlates of pedometer step counts in a sample of Australian adolescents.

The purpose of this study was to examine potential correlates of objectively measured physical activity among a sample of Australian adolescents. Participants were 119 14-15 year old students from three secondary schools. Students wore pedometers for 4 consecutive school days and completed questionnaires assessing demographic, social, psychological and behavioural correlates of physical activity. Mean steps/day were 11,865 (+/-3997) for boys (n=47) and 9466 (+/-3195) for girls (n=72). Approximately one-third of boys (32%) and girls (33%) satisfied existing step recommendations (girls 11,000 steps/day and boys 13,000 steps/day). In the first instance, the relationship between factors and physical activity was assessed using bivariate correlation. Enjoyment of physical activity (r=0.37, p<0.05), use of self-management strategies (r=0.33, p<0.05) and perceived barriers (r=-0.39, p<0.05) were significantly related to mean steps/day among boys. Peer support (r=0.26, p<0.05) and the use of self-management strategies (r=0.30, p<0.05) were significantly associated with mean steps/day for girls. Hierarchical regression analysis revealed that gender, peer support, self-management strategies and perceived barriers accounted for 16% of the variance in mean steps/day. This study has identified a number of potentially modifiable correlates of objectively measured physical activity in sample of Australian adolescents.

The Impact of Physical Activity on Brain Structure and Function in Youth: A Systematic Review.

CONTEXT: Advances in neuroimaging techniques have resulted in an exponential increase in the number of studies investigating the effects of physical activity on brain structure and function. Authors of studies have linked physical activity and fitness with brain regions and networks integral to cognitive function and scholastic performance in children and adolescents but findings have not been synthesized. OBJECTIVE: To conduct a systematic review of studies in which the impact of physical activity on brain structure and function in children and adolescents is examined. DATA SOURCES: Six electronic databases (PubMed, PsychINFO, Scopus, Ovid Medline, SportDiscus, and Embase) were systematically searched for experimental studies published between 2002 and March 1, 2019. STUDY SELECTION: Two reviewers independently screened studies for inclusion according to predetermined criteria. DATA EXTRACTION: Two reviewers independently extracted data for key variables and synthesized findings qualitatively. RESULTS: Nine studies were included (task-based functional MRI [n = 4], diffusion tensor imaging [n = 3], arterial spin labeling [n = 1], and resting-state functional MRI [n = 1]) in which results for 5 distinct and 4 similar study samples aged 8.7 ± 0.6 to 10.2 ± 1.0 years and typically of relatively low socioeconomic status were reported. Effects were reported for 12 regions, including frontal lobe (n = 3), parietal lobe (n = 3), anterior cingulate cortex (n = 2), hippocampus (n = 1), and several white matter tracts and functional networks. LIMITATIONS: Findings need to be interpreted with caution as quantitative syntheses were not possible because of study heterogeneity. CONCLUSIONS: There is evidence from randomized controlled trials that participation in physical activity may modify white matter integrity and activation of regions key to cognitive processes. Additional larger hypothesis-driven studies are needed to replicate findings.

A review of mediators of behavior in interventions to promote physical activity among children and adolescents.

BACKGROUND: The effectiveness of interventions to promote physical activity in youths is still developing. To develop a better understanding "what works", researchers are now focusing on constructing an evidence base for mediators of behavior change. METHODS: We reviewed studies that examined the direct effect of physical activity interventions on hypothesized mediators and the relationship between mediators and physical activity in young people (aged 5 to 18 years). Studies were identified via electronic database searches and scanning references against predetermined quality criteria. RESULTS: We found seven studies that evaluated three mediator groups: cognitive, behavioral and interpersonal mediators. Self-efficacy was the most commonly assessed mediator in youth interventions and there was strong support for its role in mediating the relation between theory-based interventions and physical activity. There was some support for the importance of behavioral strategies as mediators of behavior, but no support for the mediating influence of interpersonal factors. CONCLUSIONS: Despite recognition of the importance of mediation studies, few interventions have assessed mediators of physical activity behavior in youth interventions. The small number of studies examining mediators of behavior and the variability in study design and quality prevent us from forming strong conclusions regarding the most effective mediators of behavior.