Dr Jordan Smith

Physical activity (PA) is an effective and evidence-based intervention for the promotion of mental health, and prevention and treatment of mental health problems. However, little is known regarding the impact of contextual factors that may optimise the mental health benefits of PA. Contextual factors are the qualitative characteristics of PA that include its type, domain, physical and social environment, and delivery. We conducted an umbrella review of existing systematic reviews and meta-analyses of randomised controlled trials that evaluated the effect of contextual factors of PA on mental health outcomes. A total of 42 reviews were included, and covered the delivery (n = 8), social environment (n = 6), physical environment (n = 7), and type of PA (n = 33). There were no meta-analyses of randomised controlled trials pertaining to the domain of PA. Evidence showed beneficial effects for supervised PA (delivery), PA undertaken inside or outside (physical environment), PA undertaken individually or in groups (social environment), and many types of PA including aerobic and resistance training. This suggests that variations in contextual factors may play a role in enhancing the MH benefits of PA. However, few direct comparisons, and heterogenous control groups, precluded meaningful comparisons across and within contextual factors. Further, greater attention needs to be paid to the systematic testing and reporting of the contextual factors of PA to optimise mental health and wellbeing. (PROSPERO registration: BLINDED FOR REVIEW).

Background: Outdoor gym installations have become a popular initiative by local government agencies globally to increase community-based physical activity. Despite their rapid spread, usage rates and user characteristics are not well described, particularly the mode/type of activity performed. This study aims to investigate the proportion and timing of outdoor gym use, and demographic characteristics of gym users across seven locations. Method: The current study employed a cross-sectional research design with observational measures to examine outdoor gym use across seven locations in a large regional area in New South Wales, Australia. An outdoor gym audit including the number of pieces and names of the equipment, and type of outdoor gym was undertaken in the month prior to data collection. Results: A total of 56¿h of observation periods were conducted, during which 2950 individuals were observed moving through the observation target areas. Across all parks, 3.8% of individuals (n = 112) were observed using the outdoor gyms for exercise purposes. Males (65%) were more likely to be observed using the equipment than females (35%) and there were more young-to-middle aged adult (83.9%) users than seniors (6.3%), adolescents (4.5%) and children (3.6%). Conclusion: Outdoor gyms have the potential to influence community-based physical inactivity rates as they appear to be a popular strategy by many government jurisdictions globally. To increase usage, local government agencies would benefit from working collaboratively with researchers to determine effective education and promotion strategies and in developing interventions to increase usage of outdoor gym equipment, particularly among women and older adults.

The aim of our systematic review and meta-analysis was to quantitatively synthesise the effects of school-based peer-led interventions on leaders¿ academic, psychosocial, behavioural, and physical outcomes. Eligible studies were those that: (i) evaluated a school-based peer-led intervention using an experimental or quasi-experimental study design, (ii) included an age-matched control or comparison group, and (iii) evaluated the impact of the intervention on one or more leader outcomes. Medline, Sportdiscus, Psychinfo, Embase, and Scopus online databases were searched on the 24th of October, 2022 which yielded 13,572 results, with 31 included in the narrative synthesis and 12 in the meta-analysis. We found large positive effects for leaders¿ attitudes toward bullying (d = 1.02), small-to-medium positive effects for leaders¿ literacy (d = 0.39), and small positive effects for leaders¿ self-esteem (d = 0.18). There were mixed findings for behavioural outcomes and null effects for physical outcomes. Notable limitations of this research are the inclusion of a relatively small number of studies, and high heterogeneity in those included. Our findings have the potential to inform educational practice, but also highlight the need for further research examining the mechanisms that might account for the observed effects. Our systematic review was prospectively registered with PROSPERO (CRD42021273129).

Background: Adolescents with disability are less active and have lower levels of physical fitness than their typically developing peers. Schools are ideal settings to address this; however, few school-based interventions have been designed and evaluated among this group. Therefore, the aim of this pilot study was to determine the feasibility of a time-efficient school-based physical activity intervention for adolescents with disability. Methods: A non-randomized pilot trial was conducted with adolescents in the special education unit at one secondary school in New South Wales, Australia. Sixteen grade 11 and 12 students (aged 17.3 ± 0.7 years) participated in the 2-month physical activity intervention. Two classroom teachers were trained to facilitate the delivery of a high-intensity interval training (HIIT) program, known as Burn 2 Learn adapted (B2La). Teachers were asked to deliver 2¿3 weekly HIIT sessions for a period of 2 months. Four domains of feasibility (acceptability, implementation, adaptability, and practicality) were assessed using quantitative measures at the student and teacher levels (e.g., observations, process evaluation questionnaires, and heart rate [HR] monitoring). Data were also collected from three learning and support teachers who assisted classroom teachers with intervention delivery. Preliminary efficacy of the intervention on measures of adolescents¿ functional capacity (6-min walk/run test) and muscular fitness (sit-to-stand test and modified push-up test) were analyzed using paired sample t-tests. Results: Moderate-to-high levels of program satisfaction were reported by both students (80% rated ¿Good¿ or ¿Excellent¿) and teachers (100% rated ¿Good¿ or ¿Excellent¿). Teachers reported delivering 2.5 ± 0.7 sessions per week during the study. Based on researcher session observations, the program was delivered effectively by teachers (14/20). However, HR data indicated session intensity was lower than intended. The program was considered ¿adaptable¿ by teachers, with several observed modifications to HIIT sessions to cater for the needs of adolescents with disability. No adverse events were reported. We observed improvements in preliminary efficacy measures. Conclusions: Our findings suggest it is feasible to train teachers to deliver a school-based HIIT program for adolescents with disability. Evaluation of B2La within a larger-scale effectiveness trial is warranted. Trial registration: ACTRN12621000219886.

Background Cardiorespiratory fitness (CRF) is an important marker of current and future health status. The primary aim of our study was to evaluate the impact of a time-efficient school-based intervention on older adolescents' CRF. Methods Two-arm cluster randomised controlled trial conducted in two cohorts (February 2018 to February 2019 and February 2019 to February 2020) in New South Wales, Australia. Participants (N=670, 44.6% women, 16.0±0.43 years) from 20 secondary schools: 10 schools (337 participants) were randomised to the Burn 2 Learn (B2L) intervention and 10 schools (333 participants) to the control. Teachers in schools allocated to the B2L intervention were provided with training, resources, and support to facilitate the delivery of high-intensity interval training (HIIT) activity breaks during curriculum time. Teachers and students in the control group continued their usual practice. The primary outcome was CRF (20 m multi-stage fitness test). Secondary outcomes were muscular fitness, physical activity, hair cortisol concentrations, mental health and cognitive function. Outcomes were assessed at baseline, 6 months (primary end-point) and 12 months. Effects were estimated using mixed models accounting for clustering. Results We observed a group-by-time effect for CRF (difference=4.1 laps, 95% CI 1.8 to 6.4) at the primary end-point (6 months), but not at 12 months. At 6 months, group-by-time effects were found for muscular fitness, steps during school hours and cortisol. Conclusions Implementing HIIT during curricular time improved adolescents' CRF and several secondary outcomes. Our findings suggest B2L is unlikely to be an effective approach unless teachers embed sessions within the school day. Trial registration number Australian New Zealand Clinical Trials Registry (ACTRN12618000293268).

Background: ecofit is an evidence-based multi-component physical activity intervention that integrates smartphone technology, the outdoor environment, and social support. In a previous efficacy trial, significant improvements were found across several clinical, fitness, and mental health outcomes among adults at risk of (or with) type 2 diabetes. Methods: The aim of the present pilot study was to evaluate a number of patient-centered and feasibility outcomes of the ecofit intervention in a ¿real-world¿ setting, using a scalable implementation model. ecofit was adapted and implemented by a rural municipal council in the Upper Hunter Shire, New South Wales, Australia, and evaluated using a single-group pre-post design. Inactive middle-aged and older adults (N=59) were recruited and assessed at 6 (primary time-point) and 20 weeks (follow-up). Results: Improvements were found in this predominantly overweight and obese sample for aerobic fitness, functional mobility, upper and lower body muscular fitness, systolic blood pressure, and waist circumference at 6 weeks. At 20 weeks, effects were found for aerobic fitness, functional mobility, upper and lower body muscular fitness, and systolic blood pressure. Overall, participants were satisfied with the ecofit program. Participants attended the 6-week primary time-point (66.1%) and follow-up at 20 weeks (41.6%). Conclusions: Our findings support the preliminary effectiveness and feasibility of the ecofit intervention delivered by municipal council staff following a brief training from the research team. This study provides valuable preliminary evidence to support a larger implementation trial.

Background: Participation in physical activity supports greater cardiorespiratory fitness (CRF), a correlate of cognitive control. However, the relationship between muscular fitness (MF) and cognitive control is less clear. The present study investigated the differential relationship of CRF and MF with cognitive control in older adolescents. Methods: This cross-sectional study involved students (15¿17 years old, n = 541, 43% female) from 20 secondary schools who completed tests of inhibition (modified flanker task), working memory (n-back task), CRF (Progressive Aerobic Cardiovascular Endurance Run), and MF (standing long jump and push-up test). Multilevel analyses tested the association between CRF or MF and cognitive outcomes while accounting for the influence of the other fitness variable and relevant demographic factors. Results: CRF predicted response accuracy during incongruent flanker trials, the condition requiring greater inhibition. For the working memory task, CRF predicted greater target accuracy and greater d' scores on the 1-back task, requiring lesser amounts of working memory. In the 2-back task, which requires greater amounts of working memory, CRF also predicted greater target and non-target accuracy and d' scores. Comparatively, MF did not predict any cognitive outcomes after adjustment for CRF. Conclusion: CRF was selectively related to better performance during task conditions that require greater amounts of inhibition and working memory. This finding suggests that CRF, but not MF, may benefit cognitive control in older adolescents. This selective influence of CRF on older adolescents¿ cognition highlights the value of aerobic physical activity.

Background: Physical activity guidelines recommend young people engage in regular muscle-strengthening activities (e.g., resistance training [RT]). However, few school-based physical activity interventions have been delivered at-scale or promoted RT. The aim of this study was to evaluate the¿reach, effectiveness, adoption, implementation and maintenance of the Resistance Training for Teens (RT for Teens) program. Methods: Data were collected between August 2015 and October 2020. RE-AIM was operationalized as: (i) Reach: number and characteristics of students estimated to be exposed to the program; (ii) Effectiveness: impact of the program on student-level outcomes measured in a subsample of 750 students from 17 schools; (iii) Adoption: number and representativeness of schools with one or more teachers trained to deliver the program; (iv) Implementation: extent to which the program was delivered as intended; and (v) Maintenance: extent to which the program was sustained¿in schools. Results: The estimated program reach was ~ 10,000 students, out of a total student population of ~ 200,000 (~ 5%). Students were from diverse socioeconomic and ethnic backgrounds. Improvements in muscular fitness, RT self-efficacy, perceived cardiorespiratory fitness and flexibility, and participation in muscle-strengthening physical activities were documented. A total of 30 workshops were delivered, involving 468 teachers from 249 schools from diverse geographical regions. Implementation varied considerably, with teachers adapting the program to suit the¿context of their school and student cohorts. However, RT skill development and the promotion of muscular fitness were the session components delivered most during sessions. Teachers¿ adherence to the SAAFE (Supportive, Active, Autonomous, Fair and Enjoyable) teaching principles was high. Approximately 30% of teachers (144/476) registered to use the RT for Teens app. At the school-level, 37% (93/249) of schools had at least one registered user (teacher and/or student). A total of 2,336 workouts and 3,116 fitness tests were completed by registered users. Of the 249 schools represented, 51 (20.5%) sent an additional (previously untrained) teacher to a second workshop. Conclusions: The RT for Teens program had broad reach and adoption. However, intervention delivery varied considerably across schools and additional support strategies are required to optimize intervention implementation and maintain program delivery over time. Future studies will benefit from the utilization of accepted frameworks, recommendations and guidelines for implementation research. Trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12621000352808), retrospectively registered 1st February 2021.

The feasibility requirements of administering field-based cognitive assessments are rarely reported. We examined the feasibility of administering a group-based cognitive test battery in a school setting with older adolescents. Several types of reliability were also assessed in the control group. Preliminary efficacy and the relationship between changes in fitness and changes in cognitive control were also explored following a 14-week HIIT intervention (3 sessions/week). Participants completed a cognitive test battery measuring inhibition (flanker), and working memory (n-back) at baseline and post-test.¿Health-related fitness assessments were also conducted.¿Test administration took approximately 30.8¿±¿1.5¿minutes to complete with up to six participants simultaneously. The test battery demonstrated acceptable reliability (ICC¿=¿0.5¿0.81), with significant changes observed for flanker incongruent accuracy, and 2-back non-target accuracy from baseline to post-test. Regarding efficacy,¿small-to-moderate effects were observed for accuracy outcomes, while several small associations were found between changes in fitness and changes in cognition. Findings from the current study suggest a cognitive test battery can be administered with older adolescents in a school setting. However, there remains a lack of adequate reporting of administration requirements for field-based cognitive assessments. Efficacy findings should be confirmed with a larger and more representative sample of older adolescents.

Objective Muscle-strengthening exercise (use of weight machines, free weights, push-ups, sit-ups), has multiple independent health benefits, and is a component of the Global physical activity guidelines. However, there is currently a lack of multi-country muscle-strengthening exercise prevalence studies. This study describes the prevalence and correlates of musclestrengthening exercise across multiple European countries. Methods Data were drawn from the European Health Interview Survey Wave 2 (2013-14), which included nationally representative samples (n = 3,774-24,016) from 28 European countries. Muscle-strengthening exercise was assessed using the European Health Interview Survey Physical Activity Questionnaire. Population-weighted proportions were calculated for (1) "insufficient"(0-1 days/week) or (2) "sufficient"muscle-strengthening exercise ((=2 days/ week). Prevalence ratios were calculated using multivariate Poisson regression for those reporting sufficient muscle-strengthening by country and by sociodemographic/lifestyle characteristics (sex, age, education, income, self-rated health etc.). Results Data were available for 280,605 European adults aged (=18 years. Overall, 17.3% (95% CI = 17.1%-17.5%) reported sufficient muscle-strengthening exercise (=2 days/week). Muscle-strengthening exercise was geographically patterned with the lowest prevalence reported in South-eastern European countries (Romania, Malta and Cyprus: Range: 0.7%- 7.4%), and the highest prevalence in the Nordic countries (Iceland, Sweden, and Denmark: Range: 34.1%-51.6%). Older age, insufficient aerobic activity, poorer self-rated health, lower income/education, being female, and being overweight/obese were significantly associated with lower likelihood of reporting sufficient muscle-strengthening exercise, independently of other characteristics. Conclusions Most European adults do not report sufficient muscle-strengthening exercise, and prevalence estimates varied considerably across countries. Low participation in muscle-strengthening exercise is widespread across Europe, and warrants public health attention.

Objective: To estimate national and international temporal trends in handgrip strength for children and adolescents, and to examine relationships between trends in handgrip strength and trends in health-related and sociodemographic indicators. Methods: Data were obtained through a systematic search of studies reporting temporal trends in the handgrip strength for apparently healthy 9¿17-year-olds, and by examining large national fitness datasets. Temporal trends at the country¿sex¿age level were estimated by sample-weighted regression models relating the year of testing to mean handgrip strength. International and national trends were estimated by a post-stratified population-weighting procedure. Pearson¿s correlations quantified relationships between national trends in handgrip strength and national trends in health-related/sociodemographic indicators. Results: 2,216,320 children and adolescents from 13 high-, 5 upper-middle-, and 1 low-income countries/special administrative regions between 1967 and 2017 collectively showed a moderate improvement of 19.4% (95% CI 18.4¿20.4) or 3.8% per decade (95% CI 3.6¿4.0). The international rate of improvement progressively increased over time, with more recent values (post-2000) close to two times larger than those from the 1960s/1970s. Improvements were larger for children (9¿12¿years) compared to adolescents (13¿17¿years), and similar for boys and girls. Trends differed between countries, with relationships between national trends in handgrip strength and national trends in health-related/sociodemographic indicators negligible-to-weak and not statistically significant. Conclusions: There has been a substantial improvement in absolute handgrip strength for children and adolescents since 1967. There is a need for improved international surveillance of handgrip strength, especially in low- and middle-income countries, to more confidently determine true international trends. PROSPERO Registration Number: CRD42013003657.

Introduction: Secondary schools have the potential to promote health-related fitness (HRF) and physical activity within and outside school hours. As such, schools are often chosen as the setting to implement child and adolescent physical activity programs. School-based programs often utilise teachers as delivery agents, but few studies examine effects on teacher-level outcomes. Purpose: The primary aim of this study was to determine the impact of teacher training embedded within a physical activity intervention on teacher-level outcomes. The secondary aim of this study was to evaluate process data, including implementation, satisfaction and fidelity. Methods:Resistance Training for Teens (RT for Teens) was evaluated using a cluster randomised controlled trial in 16 secondary schools. Teachers (N = 44; 48% female/52% male; mean ± SD years teaching experience = 10.6 ± 8.0) from 16 secondary schools were assessed at baseline. Intervention group teachers (i.e. from eight schools) delivered a structured school-based physical activity program over 10-weeks. Teacher outcomes included confidence to teach health-related fitness (HRF) activities, perceived barriers to teaching HRF activities, and perceived fitness. Detailed process evaluation data were also collected. Assessments were conducted at baseline and 6-months (post-program), and outcomes were assessed using repeated measures analysis of variance. Results: There was a positive group-by-time effect for the confidence composite score (p =.010, partial eta squared = 0.29), but no effects for the two (contextual, interpersonal) barrier composite scores. Also, there was a significant effect for perceived ¿general fitness¿ (p = 0.044, partial eta squared = 0.13), but not for specific fitness subdomains. Teachers were highly satisfied with both the training and the program, believing it was beneficial for students. Resource usage and adherence to the SAAFE (Supportive, Active, Autonomous, Fair, Enjoyable) delivery principles was high. Conclusion:RT for Teens improved teachers¿ confidence and perceived fitness. These findings highlight the potential for high-quality teacher training and program delivery to positively influence teacher-level outcomes. This may provide support for the use of teacher professional development to improve HRF-related pedagogy.

Objectives: While outdoor gyms are being rapidly installed around the globe, little is known about their implications on physical activity, and fitness and other health-related outcomes. The primary objective of this systematic review was to examine the effects of outdoor gyms on physical activity, fitness and other health-related outcomes. Secondary objectives were to describe outdoor gym characteristics, user characteristics, and outdoor gym usage. Design: Systematic review. Methods: Peer-reviewed papers published in English were obtained through online database searches of the following databases; EBSCO, SPORTdiscus, Medline, PsycINFO, Web of Science, Scopus and Informit. Searches covered the periods from database inception to January 2019. Studies that reported on the efficacy of outdoor gym use for physical activity, health-related outcomes or descriptive aspects of outdoor gyms and their users were eligible for inclusion. Results: There was some support that outdoor gyms may improve physical activity, fitness and other health-related outcomes, however few experimental studies have been conducted. There was no consistency between outdoor gyms in terms types and number of installed equipment for each facility. Further, this review found discrepancies of whom were the most likely users of outdoor gyms and when they were mainly used. Conclusions: This review contributes to the limited evidence on the impact and characteristics of outdoor gyms on physical activity and fitness and health-related outcomes.

Purpose: Guidelines recommend that young people engage in muscle-strengthening activities on at least 3 dIwkj1. The purpose of this study was to examine the effect of a school-based intervention focused on resistance training (RT) for adolescents. Methods: The ''Resistance Training for Teens'' intervention was evaluated using a cluster-randomized, controlled trial with 607 adolescents (50.1% girls; 14.1 T 0.5 yr) from 16 secondary schools. Teachers were trained to deliver the intervention, which included the following: (i) an interactive student seminar; (ii) a structured physical activity program, focused on RT; (iii) lunchtime fitness sessions; and (iv) Web-based smartphone apps. The primary outcome was muscular fitness (MF) and secondary outcomes included body mass index, RT skill competency, flexibility, physical activity, self-efficacy, and motivation. Assessments were conducted at baseline, 6 months (postprogram; primary end point), and 12 months (follow-up). Outcomes were assessed using linear mixed models, with three potential moderators tested using interaction terms (and subgroup analyses where appropriate). Results: For the primary outcome (MF), a group-time effect was observed at 6 months for the upper body (2.0 repetitions; 95% confidence interval (CI), 0.8-3.2), but not the lower body (j1.4 cm; 95% CI, j4.7-1.9). At 6 months, there were intervention effects for RT skill competency and self-efficacy, but no other secondary outcomes. Effects for upper body MF and RT skill competency were sustained at 12 months. Despite overall no effect for body mass index, there was a group-time effect at 12 months among students whowere overweight/obese at baseline (j0.55 kgImj2; 95% CI, j1.01 toj0.08). Conclusions: The school-based RT intervention resulted in immediate and sustained improvements in upper body MF and RT skill competency, demonstrating an effective and scalable approach to delivering RT within secondary schools.

Objective: To examine the impact of a school-based physical activity intervention on adolescents' self-esteem and subjective well-being, and to explore moderators and mediators of intervention effects. Methods: Resistance Training for Teens was evaluated using a cluster RCT in 16 schools located in New South Wales, Australia. Adolescents (N = 508; 14.1 ± 0.5 years; 49.6% female) completed measures of global self-esteem, subjective well-being, and hypothesized mediators (i.e., perceived fitness, resistance training self-efficacy, and autonomous motivation) at baseline (April¿June, 2015) and post-intervention (October¿December). The school-based physical activity program was delivered by teachers over 10-weeks via Physical Education, co-curricular school sport, or an elective subject known as Physical Activity and Sport Studies, and involved once-weekly fitness sessions and additional lunch-time sessions. Intervention effects and moderator analyses were tested using multi-level linear regression analyses with interaction terms. Multi-level mediation analyses were used to explore potential mediators of changes in well-being outcomes. Results: Intervention effects for self-esteem (ß = 0.05, p =.194) and wellbeing (ß = 0.03, p =.509) were not statistically significant. Moderator analyses showed effects for self-esteem were greater for the overweight/obese subgroup (p =.069 for interaction), and resistance training self-efficacy was a significant mediator of changes in self-esteem (product-of-coefficients [AB] = 0.021, SE = 0.010, 95% CIs = 0.002 to 0.040). No other significant indirect effects were observed. Conclusion: Overall, Resistance Training for Teens did not improve adolescents' self-esteem or subjective well-being. However, our mediation findings lend support to resistance training self-efficacy as a mechanism explaining the positive effect of resistance training on self-esteem.

The aim of this study is to examine the prevalence and correlates of adolescents¿ resistance training (RT) skill competence. Participants were 548 adolescents (14.1¿±¿0.5¿years) from 16 schools in New South Wales, Australia. RT skills were assessed using the Resistance Training Skills Battery. Demographics, BMI, muscular fitness, perceived strength, RT self-efficacy, and motivation for RT were also assessed. The proportion demonstrating ¿competence¿ and ¿near competence¿ in each of the six RT skills were calculated and sex differences explored. Associations between the combined RT skill score and potential correlates were examined using multi-level linear mixed models. Overall, the prevalence of competence was low (range¿=¿3.3% to 27.9%). Females outperformed males on the squat, lunge and overhead press, whereas males performed better on the push-up (p¿<.05). Significant associations were seen for a number of correlates, which largely differed by sex. Muscular fitness was moderately and positively associated with RT skills among both males (ß¿=¿0.34, 95%CIs¿=¿0.23 to 0.46) and females (ß¿=¿0.36, 95%CIs¿=¿0.23 to 0.48). Our findings support a link between RT skills and muscular fitness. Other associations were statistically significant but small in magnitude, and should therefore be interpreted cautiously.

Objective The present study examined the effect of a school-based multicomponent physical activity intervention on aggression in adolescent males from low-income areas, and explored potential mediators of change in aggression. Methods Participants were adolescent males (N = 361; 12.7 ± 0.5 years) enrolled in the ¿Active Teen Leaders Avoiding Screen-time¿ cluster RCT. Self-report measures for aggression, perceived strength and recreational screen-time were collected at baseline and 8-months. The effect of the intervention on aggression was tested using multi-level linear regression and potential mediators (i.e., screen-time and perceived strength) were explored using a product-of-coefficients test. Results There was no significant intervention effects for aggression (C [SE] = -0.038 [0.044], p =.384) or perceived strength (A [SE] = -0.0 [0.0], p =.884). However, a statistically significant effect was found for screen-time (A [SE] = -0.160 [0.04], p= <0.01). Changes in screen-time significantly mediated changes in aggression at post-test (AB [SE] = -0.021 [0.009], 95% CI = -0.042 to -0.005). Conclusion Limiting recreational screen-time may help to reduce aggression in adolescent boys. Interventions targeting adolescents' recreational screen-time should examine their ¿flow-on¿ effects on externalising behaviours in adolescent populations.

This review aimed to determine the most popular physical activities performed by children, adolescents, and adults globally. Statistic bureau websites and article databases Scopus, ProQuest, SPORTDiscus, and Science Direct were searched between November 17th, 2014 and April 31st, 2015. Eligible studies were published in the last 10¿years with participation rates for specific physical activities among individuals five years or older. Data extraction for included articles (n¿=¿64) was assessed independently and agreed upon by two authors. A random-effects model was used to calculate participation rates in specific activities for each age group and region. In total 73,304 articles were retrieved and 64 articles representing 47 countries were included in the final meta-analysis. Among adults, walking was the most popular activity in the Americas (18.9%; 95% CI 10.2 to 32.5), Eastern Mediterranean (15.0%; 95% CI 5.8 to 33.6), Southeast Asia (39.3%; 95% CI 0.9 to 98.0) and Western Pacific (41.8%; 95% CI 25.2 to 60.6). In Europe and Africa, soccer (10.0%; 95% CI 6.5 to 15.1) and running (9.3%; 95% CI 0.9 to 53.9), respectively, were top activities. Child and adolescent participation results were highly dependent upon region. American youth team sport participation was high, while youth from the Eastern Mediterranean and Western Pacific were more likely to report participation in lifelong physical activities. Global data for adults reflects a consistent pattern of participation in running and walking. Among all age groups and regions soccer was popular. In children and adolescents, preferences were variable between regions.

Introduction The primary aim was to examine longitudinal associations between changes in screen-time and mental health outcomes among adolescents. Methods Adolescents (N¿=¿322, 65.5% females, mean age¿=¿14.4¿±¿0.6 years) reported screen-time and mental health at two time points over a school year. Multi-level linear regression analyses were conducted after adjusting for covariates. Results Changes in total recreational screen-time (ß¿=¿-0.09 p¿=¿0.048) and tablet/mobile phone use (ß¿=¿-0.18, p¿<¿0.001) were negatively associated with physical self-concept. Changes in total recreational screen-time (ß¿=¿-0.20, p¿=¿0.001) and computer use (ß¿=¿-0.23, p¿=¿0.003) were negatively associated with psychological well-being. A positive association was found with television/DVD use and psychological difficulties (ß¿=¿0.16, p¿=¿0.015). No associations were found for non-recreational screen-time. Conclusion Changes in recreational screen-time were associated with changes in a range of mental health outcomes.

The risk and prevalence of Type 2 Diabetes (T2D) has dramatically increased over the past decade. The aim of this study was to develop, implement and evaluate a physical activity intervention to improve aerobic and muscular fitness among adults at risk of, or diagnosed with T2D. A 20-week, assessor blinded, parallel-group randomized controlled trial (RCT) was conducted at the University of Newcastle (June¿December 2015). Adults were randomized to the intervention (n = 42) or wait-list control group (n = 42). The theory-based intervention included: Phase 1 (weeks 1¿10) integrated group sessions (outdoor physical activity and cognitive mentoring), and the eCoFit smartphone application (app). Phase 2 (weeks 11¿20) only included the eCoFit app. Participants were assessed at baseline, 10 weeks and 20 weeks. Linear mixed models (intention-to-treat) were used to determine group-by-time interactions at 10 weeks (primary time-point) and 20 weeks for the primary outcomes. Several secondary outcomes were also assessed. After 10 weeks, significant group-by-time effects were observed for aerobic fitness (4.5 mL/kg/min; 95% CI [1.3, 7.7], d = 0.68) and muscular fitness (lower body) (3.4 reps, 95% CI [2.7, 4.2], d = 1.45). Intervention effects for secondary outcomes included significant increased physical activity (1330 steps/week), improved upper body muscular fitness (5 reps; arm-curl test), improved functionality (- 1.8 s; timed-up and go test) reduced waist circumference (2.8 cm) and systolic blood pressure (- 10.4 mm Hg). After 20 weeks, significant effects were observed for lower body muscular fitness and health outcomes. eCoFit is an innovative lifestyle intervention which integrates smartphone technology, social support, and the outdoor environment to improve aerobic and muscular fitness.

The mechanisms of behavior change in youth screen-time interventions are poorly understood. Participants were 361 adolescent boys (12¿14¿years) participating in the ATLAS obesity prevention trial, evaluated in 14 schools in low-income areas of New South Wales, Australia. Recreational screen-time was assessed at baseline, 8- and 18-months, whereas potential mediators (i.e., motivation to limit screen-time and parental rules) were assessed at baseline, 4- and 18-months. Multi-level mediation analyses followed the intention-to-treat principle and were conducted using a product-of-coefficients test. The intervention had a significant impact on screen-time at both time-points, and on autonomous motivation at 18-months. Changes in autonomous motivation partially mediated the effect on screen-time at 18-months in single and multi-mediator models [AB (95% CI)¿=¿-5.49 (-12.13, -.70)]. Enhancing autonomous motivation may be effective for limiting screen-time among adolescent males. Trial registration: Australian New Zealand Clinical Trials Registry No: ACTRN12612000978864.

Objective: The aims of this systematic review and meta-analysis are (i) to determine the impact of school-based interventions on objectively measured physical activity among adolescents and (ii) to examine accelerometer methods and decision rule reporting in previous interventions. Methods: A systematic search was performed to identify randomized controlled trials targeting adolescents (age: =10¿years), conducted in the school setting, and reporting objectively measured physical activity. Random effects meta-analyses were conducted to determine the pooled effects of previous interventions on total and moderate-to-vigorous physical activity. Potential moderators of intervention effects were also explored. Results: Thirteen articles met the inclusion criteria, and twelve were included in the meta-analysis. The pooled effects were small and non-significant for both total physical activity (standardized mean difference¿=¿0.02 [95% confidence interval¿=¿-0.13 to 0.18]) and moderate-to-vigorous physical activity (standardized mean difference¿=¿0.24 [95% confidence interval¿=¿-0.08 to 0.56]). Sample age and accelerometer compliance were significant moderators for total physical activity, with a younger sample and higher compliance associated with larger effects. Conclusion: Previous school-based physical activity interventions targeting adolescents have been largely unsuccessful, particularly for older adolescents. There is a need for more high-quality research using objective monitoring in this population. Future interventions should comply with best-practice recommendations regarding physical activity monitoring protocols.

Purpose: The aim of this study was to explore the effect of the Active Teen Leaders Avoiding Screen-time (ATLAS) intervention on psychological well-being in adolescent boys and to examine the potential mediating mechanisms that might explain this effect. Methods: ATLAS was evaluated using a cluster randomized controlled trial in 14 secondary schools located in low-income communities (N = 361 adolescent boys, mean age = 12.7 ±.5 years). The 20-week intervention was guided by self-determination theory and involved: professional development for teachers, provision of fitness equipment to schools, enhanced school sport sessions, researcher-led seminars, a smartphone application, and parental strategies for reducing screen time. Assessments were conducted at baseline and immediately post intervention (8 months). Psychological well-being was measured using the Flourishing Scale. Motivational regulations (intrinsic, identified, introjected, controlled, and amotivation) and basic psychological needs (autonomy, competence, and relatedness) in school sport, muscular fitness, resistance training skill competency, and recreational screen time were examined as potential mediating mechanisms of the intervention effect. Results: The intervention effect on well-being was small but statistically significant. Within a multiple mediator model, changes in autonomy needs satisfaction, recreational screen time, and muscular fitness significantly mediated the effect of the intervention on psychological well-being. Conclusions: In addition to the physical health benefits, targeted physical activity programs for adolescent boys may have utility for mental health promotion through the mechanisms of increasing autonomy support and muscular fitness and reducing screen time.

Introduction The primary objective was to evaluate the impact of the ¿Switch-off 4 Healthy Minds¿ (S4HM) intervention on recreational screen-time in adolescents. Methods Cluster randomized controlled trial with study measures at baseline and 6-months (post-intervention). Eligible participants reported exceeding recreational screen-time recommendations (i.e., >¿2¿h/day). In total, 322 adolescents (mean age¿=¿14.4¿±¿0.6¿years) from eight secondary schools in New South Wales, Australia were recruited. The S4HM intervention was guided by Self-Determination Theory and included: an interactive seminar, eHealth messaging, a behavioral contract and parental newsletters. The primary outcome was recreational screen-time. Secondary outcomes included mental health (i.e., well-being, psychological distress, self-perceptions), objectively measured physical activity, and body mass index (BMI). Outcome analyses were conducted using linear mixed models and mediation was examined using a product-of-coefficients test. Results At post-intervention, significant reductions in screen-time were observed in both groups, with a greater reduction observed in the intervention group (-¿50¿min/day versus -¿29¿min, p¿<¿0.05 for both). However, the adjusted difference in change between groups was not statistically significant (mean¿=¿-¿21.3¿min/day, p¿=¿0.255). There were no significant intervention effects for mental health outcomes, physical activity or BMI. Significant mediation effects for autonomous motivation were found. Conclusions Participants in both the S4HM intervention and control groups significantly reduced their screen-time, with no group-by-time effects. Enhancing autonomous motivation might be a useful intervention target for trials aimed at reducing adolescents' recreational screen-time. Trial registration ACTRN12614000163606.

Background: Obesity prevention interventions targeting 'at-risk' adolescents are urgently needed. The aim of this study is to evaluate the sustained impact of the 'Active Teen Leaders Avoiding Screen-time' (ATLAS) obesity prevention program. Methods: Cluster RCT in 14 secondary schools in low-income communities of New South Wales, Australia. Participants were 361 adolescent boys (aged 12-14 years) 'at risk' of obesity. The intervention was based on Self-Determination Theory and Social Cognitive Theory and involved: professional development, fitness equipment for schools, teacher-delivered physical activity sessions, lunch-time activity sessions, researcher-led seminars, a smartphone application, and parental strategies. Assessments for the primary (body mass index [BMI], waist circumference) and secondary outcomes were conducted at baseline, 8- (post-intervention) and 18-months (follow-up). Analyses followed the intention-to-treat principle using linear mixed models. Results: After 18-months, there were no intervention effects for BMI or waist circumference. Sustained effects were found for screen-time, resistance training skill competency, and motivational regulations for school sport. Conclusions: There were no clinically meaningful intervention effects for the adiposity outcomes. However, the intervention resulted in sustained effects for secondary outcomes. Interventions that more intensively target the home environment, as well as other socio-ecological determinants of obesity may be needed to prevent unhealthy weight gain in adolescents from low-income communities. Trial registration: Australian Clinical Trial Registry ACTRN12612000978864.

This article presents a conceptual model illustrating a targeted approach to the design and delivery of health behavior interventions that focus on physical activity promotion. We hypothesize that researchers who i) enhance the sociocultural relevance of their core intervention components and ii) recognize the unique contributions of both intervention design and delivery will experience greater intervention engagement and improved outcomes.

The purpose of this study was to examine the mediating effect of resistance training skill competency on percentage of body fat, muscular fitness and physical activity among a sample of adolescent boys participating in a school-based obesity prevention intervention. Participants were 361 adolescent boys taking part in the Active Teen Leaders Avoiding Screen-time (ATLAS) cluster randomised controlled trial: a school-based program targeting the health behaviours of economically disadvantaged adolescent males considered ¿at-risk¿ of obesity. Body fat percentage (bioelectrical impedance), muscular fitness (hand grip dynamometry and push-ups), physical activity (accelerometry) and resistance training skill competency were assessed at baseline and post-intervention (i.e., 8 months). Three separate multi-level mediation models were analysed to investigate the potential mediating effects of resistance training skill competency on each of the study outcomes using a product-of-coefficients test. Analyses followed the intention-to-treat principle. The intervention had a significant impact on the resistance training skill competency of the boys, and improvements in skill competency significantly mediated the effect of the intervention on percentage of body fat and the combined muscular fitness score. No significant mediated effects were found for physical activity. Improving resistance training skill competency may be an effective strategy for achieving improvements in body composition and muscular fitness in adolescent boys.

The primary aim of this study was to examine the association between the types of video games played by adolescent boys and their participation in physical activity and recreational screen-time. Participants were 320 boys (mean age=12.7, ±0.5 years) from 14 secondary schools located in low-income areas of New South Wales, Australia. Outcomes included height, weight, physical activity (accelerometers), total screen-time, and video game genre preference. Significant differences in both weekday and weekend screen-time were found between video game genre groups. In addition, significant differences in overall activity and moderate-to-vigorous physical activity were found between genre groups on weekdays. Between-group differences in physical activity on weekends were not statistically significant. This cross-sectional study has demonstrated that video game genre preference is associated with physical activity and screen-time in adolescent boys from low-income communities.

Objective: Self-determination theory is used as a framework for examining the relation between motivation and physical activity. The purpose of this review was to systematically review studies that assessed the association between self-determined motivation and physical activity levels in children and adolescents. Method: We searched electronic databases in April 2013. Included studies assessed the relation between motivation (as outlined in self-determination theory) and physical activity in children and adolescents. Results: Forty-six studies ( n=15,984 participants) met the inclusion criteria. Meta-analysis indicated that overall levels of self-determined motivation had a weak to moderate, positive associations with physical activity ( ¿=.21 to .31). Autonomous forms of motivation (i.e., intrinsic motivation and identified regulation) had moderate, positive associations with physical activity ( ¿=.27 to .38), whereas controlled forms of motivation (i.e., introjection and external regulation) had weak, negative associations with physical activity ( ¿=.03 to 17). Amotivation had a weak, negative association with physical activity ( ¿=.11 to 21). Conclusions: Evidence provides some support for self-determination theory tenets. However, there was substantial heterogeneity in most associations and many studies had methodological shortcomings. © 2014.

The aim of this study was to describe the development and assess test-retest reliability and construct validity of the Resistance Training Skills Battery (RTSB) for adolescents. The RTSB provides an assessment of resistance training skill competency and includes 6 exercises (i.e., body weight squat, push-up, lunge, suspended row, standing overhead press, and front support with chest touches). Scoring for each skill is based on the number of performance criteria successfully demonstrated. An overall resistance training skill quotient (RTSQ) is created by adding participants' scores for the 6 skills. Participants (44 boys and 19 girls, mean age = 14.5 ± 1.2 years) completed the RTSB on 2 occasions separated by 7 days. Participants also completed the following fitness tests, which were used to create a muscular fitness score (MFS): handgrip strength, timed push-up, and standing long jump tests. Intraclass correlation (ICC), paired samples t-tests, and typical error were used to assess test-retest reliability. To assess construct validity, gender and RTSQ were entered into a regression model predicting MFS. The rank order repeatability of the RTSQ was high (ICC = 0.88). The model explained 39% of the variance in MFS (p = 0.001) and RTSQ (r = 0.40, p = 0.001) was a significant predictor. This study has demonstrated the construct validity and test-retest reliability of the RTSB in a sample of adolescents. The RTSB can reliably rank participants in regards to their resistance training competency and has the necessary sensitivity to detect small changes in resistance training skill proficiency. © 2014 National Strength and Conditioning Association.

Introduction: The negative consequences of unhealthy weight gain and the high likelihood of pediatric obesity tracking into adulthood highlight the importance of targeting youth who are 'at risk' of obesity. The aim of this paper is to report the rationale and study protocol for the 'Active Teen Leaders Avoiding Screen-time' (ATLAS) obesity prevention intervention for adolescent boys living in low-income communities. Methods/design: The ATLAS intervention will be evaluated using a cluster randomized controlled trial in 14 secondary schools in the state of New South Wales (NSW), Australia (2012 to 2014). ATLAS is an 8-month multi-component, school-based program informed by self-determination theory and social cognitive theory. The intervention consists of teacher professional development, enhanced school-sport sessions, researcher-led seminars, lunch-time physical activity mentoring sessions, pedometers for self-monitoring, provision of equipment to schools, parental newsletters, and a smartphone application and website. Assessments were conducted at baseline and will be completed again at 9- and 18-months from baseline. Primary outcomes are body mass index (BMI) and waist circumference. Secondary outcomes include BMI z-scores, body fat (bioelectrical impedance analysis), physical activity (accelerometers), muscular fitness (grip strength and push-ups), screen-time, sugar-sweetened beverage consumption, resistance training skill competency, daytime sleepiness, subjective well-being, physical self-perception, pathological video gaming, and aggression. Hypothesized mediators of behavior change will also be explored. Discussion: ATLAS is an innovative school-based intervention designed to improve the health behaviors and related outcomes of adolescent males in low-income communities. © 2013 Elsevier Inc.

OBJECTIVE: The goal of this study was to evaluate the impact of the Active Teen Leaders Avoiding Screen-time (ATLAS) intervention for adolescent boys, an obesity prevention intervention using smartphone technology.