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.

Pilot randomized controlled trial of a game-based intervention for teaching basketball in Chinese primary school physical education.

This study aimed to examine the preliminary efficacy and feasibility of implementing a tailored version of the MASTER coach education programme in Chinese primary schools to support physical education (PE) teachers' basketball lesson design and delivery. A total of 20 primary schools in Beijing, China were recruited, with one PE teacher and their class (N = 715 students aged 10-13 yrs) from each school included in the study and randomly allocated to the MASTER intervention (n = 10) or control group (n = 10). Compared to the control group, a significant difference was observed in the MASTER group for the proportion of playing-form activities delivered during PE (27.65, 95% CI [20.27, 35.03]) and for teachers' perceptions of confidence (23.92, 95% CI [15.87, 31.92]) and competence (24.12, 95% CI [10.28, 24.71]) to teach. Significant differences between groups were observed for students' perceived athletic competence (3.56%; 95% CI [3.15, 3.96]), enjoyment (11.83%; 95% CI [10.98, 12.69]), well-being (8.51%; 95% CI [7.02, 10.00]), intrinsic motivation (+0.74%; 95% CI [0.30, 1.17]), introjected motivation (-2.24%; 95% CI [-2.77, -1.70]), and external motivation (-0.49%; 95% CI [-0.90, -0.08]). The MASTER programme was effective in improving teaching practices in Chinese primary schools, and in facilitating improvements in teacher and student outcomes.

Mediating effects of sleep on mental health in older adolescents: Findings from the Burn 2 Learn randomized controlled trial.

PURPOSE: Our study explored the mediating effect of sleep-related variables on older adolescents' mental health in the context of a school-based physical activity intervention. METHODS: We evaluated the Burn 2 Learn (B2L) intervention using a cluster randomized controlled trial, which included two cohorts. Participants for this sub-study were from the second cohort, which included 292 older adolescents (16.0 ± 0.5 years) from 10 secondary schools in New South Wales, Australia. Teachers at intervention schools delivered two high-intensity activity breaks (approximately 10 mins) per week to students during academic lessons. Participants completed measures of mental health (i.e., perceived stress and internalizing problems) and hypothesized mediators (i.e., sleep duration, sleep latency, awakenings, and daytime sleepiness) at baseline (February-April 2019) and post-intervention (August-September 2019). Single mediation analyses were conducted to explore the potential mediating effects of sleep variables on mental health outcomes using a product-of-coefficient test. RESULTS: We observed a small statistically significant effect for perceived stress (ß = -0.11, SE = 0.034, p = 0.002), but not for internalizing problems (ß = 0.02, SE = 0.051, p = 0.760). There were no significant intervention effects for sleep-related variables. Several sleep-related variables were associated with mental health outcomes but no mediated effects were found. CONCLUSION: The B2L intervention had a small beneficial effect on perceived stress, however our mediation analyses suggest this was not explained by changes in sleep-related variables. Markers of sleep were associated with mental health constructs, highlighting the importance of sleep for good psychological health. However, in the context of a physical activity intervention, effects on mental health may be driven by other behavioral, neurobiological, or psychosocial mechanisms.

Investigating the direct and indirect effects of a school-based leadership program for primary school students: Rationale and study protocol for the 'Learning to Lead' cluster randomised controlled trial.

BACKGROUND: Leadership is a valuable skill that can be taught in school, and which may have benefits within and beyond the classroom. Learning to Lead (L2L) is a student-led, primary school-based leadership program whereby older 'peer leaders' deliver a fundamental movement skills (FMS) program to younger 'peers' within their own school. AIM: The aims of the study are to determine the efficacy of a peer-led FMS intervention on: (i) peer leaders' (aged 10 to 12 years) leadership effectiveness (primary outcome), leadership self-efficacy, well-being, and time on-task in the classroom; (ii) peers' (aged 8 to 10 years) physical activity levels, actual and perceived FMS competency, cardiorespiratory fitness, muscular power, and executive functioning; and (iii) teachers' (referred to as 'school champions') work-related stress and well-being. METHOD: L2L will be evaluated using a two-arm parallel group cluster randomised controlled trial. Twenty schools located within a two-hour drive of the University of Newcastle, Australia will be recruited. We will recruit 80 students (40 peer leaders and 40 peers) from each school (N = 1,600). L2L will be implemented in three phases: Phase 1 -school champions' training via a professional learning workshop; Phase 2 -school champions' delivery of leadership lessons to the peer leaders; and Phase 3 -peer leaders' delivery of the FMS program to their younger peers. The FMS program, consisting of 12 x 30-minute lessons, will be delivered over the course of one school term (10 weeks). Study outcomes will be assessed at baseline (between mid-March to June, Terms 1 and 2), intervention end (mid-August to September, Term 3), and follow-up (November to mid-December, Term 4. This trial was prospectively registered on the Australian New Zealand Clinical Trials Registry (ANZCTR); registration number: ACTRN12621000376842.

Sex moderates the associations between physical activity intensity and attentional control in older adolescents.

INTRODUCTION: The relationship between physical activity (PA) intensity and executive functions in older adolescents remains poorly understood. This study aimed to examine the associations between PA intensity, volume, attentional control, and working memory and the moderating effects of sex in older adolescents. METHOD: We analyzed baseline data from 418 participants (211 females, Mage  = 16.5 ± 0.40 years) from the Burn 2 Learn trial. Adolescents wore GT9X Link accelerometers on a non-dominant wrist for 7 days, 24-h·d-1 . PA intensity was expressed as intensity gradient (IG) and moderate-to-vigorous PA (MVPA, Hildebrand cut-points); PA volume was expressed as average acceleration (AvACC). Attentional control was measured with a standard deviation (SDRT) and a coefficient of variation (CVRT) of the reaction time on the incongruent trials of a flanker task. Working memory was expressed as a d prime (a signal discrimination index) on the 2-back task. The moderating effects of sex on the PA-executive functions associations, adjusting for age, BMI z-score, and cardiorespiratory fitness, were tested using multilevel random intercept models. RESULTS: After controlling for AvACC, sex moderated the relationships between IG and incongruent SDRT (B = 0.53, 95% CI: 0.12, 0.94) and CVRT (B = 0.63, 95% CI: 0.22, 1.05; ps ≤ 0.002). Only girls with higher IG showed smaller incongruent SDRT and CVRT (Bs ≤ -0.26, ps ≤ 0.01). IG was not related to working memory. AvACC and MVPA were not associated with attentional control or working memory. CONCLUSION: Our findings reveal a novel association between higher-intensity PA and superior attentional control among adolescent girls.

A systematic review and meta-analysis of the benefits of school-based, peer-led interventions for leaders.

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).

Time-efficient physical activity intervention for older adolescents with disability: rationale and study protocol for the Burn 2 Learn adapted (B2La) cluster randomised controlled trial.

INTRODUCTION: Physical activity declines during adolescence, with the lowest levels of activity observed among those with disability. Schools are ideal settings to address this issue; however, few school-based interventions have been specifically designed for older adolescents with disability. Our aim is to investigate the effects of a school-based physical activity programme, involving high-intensity interval training (HIIT), on physical, mental and cognitive health in older adolescents with disability. METHODS AND ANALYSIS: We will evaluate the Burn 2 Learn adapted (B2La) intervention using a two-arm, parallel group, cluster randomised controlled trial with allocation occurring at the school level (treatment or waitlist control). Secondary schools will be recruited in two cohorts from New South Wales, Australia. We will aim to recruit 300 older adolescents (aged 15-19 years) with disability from 30 secondary schools (10 in cohort 1 and 20 in cohort 2). Schools allocated to the intervention group will deliver two HIIT sessions per week during scheduled specialist support classes. The sessions will include foundational aerobic and muscle strengthening exercises tailored to meet student needs. We will provide teachers with training, resources, and support to facilitate the delivery of the B2La programme. Study outcomes will be assessed at baseline, 6 months (primary endpoint), and 9 months. Our primary outcome is functional capacity assessed using the 6 min walk/push test. Secondary outcomes include physical activity, muscular fitness, body composition, cognitive function, quality of life, physical literacy, and on-task behaviour in the classroom. We will also conduct economic and process evaluations to determine cost-effectiveness, programme acceptability, implementation, adaptability, and sustainability in schools. ETHICS AND DISSEMINATION: This study has received approval from the University of Newcastle (H-2021-0262) and the New South Wales Department of Education (SERAP: 2021257) human research ethics committees. Findings will be published in peer-reviewed journals, and key stakeholders will be provided with a detailed report following the study. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry Number: ACTRN12621000884808.

Physical Activity, Fitness, and Executive Functions in Youth: Effects, Moderators, and Mechanisms.

Over the last decade, a growing body of research has examined the link between physical activity, fitness, and cognitive function in children and adolescents. Physical activity experimental research conducted with children and adolescents has identified selectively greater effects for tasks requiring higher order executive functions. As such, the primary aim of our chapter is to provide an overview of findings from systematic reviews and meta-analyses that have examined the effects of physical activity on measures of executive function in child and adolescent populations. We begin our chapter with definitions of key concepts associated with physical activity, fitness and cognitive function. We then provide a synthesis of systematic reviews and meta-analyses that have examined the acute and chronic effect of physical activity on EFs. Following this, we discuss the quantitative (e.g., time, intensity) and qualitative (e.g., type) characteristics of physical activity that may moderate effects. The next section focuses on the neurobiological, psychosocial and behavioral mechanisms responsible for the effect of physical activity on executive functions. We conclude by highlighting the limitations of the existing evidence base and providing recommendations for future research.

Feasibility of a school-based physical activity intervention for adolescents with disability.

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 .

Cardiorespiratory and muscular fitness associations with older adolescent cognitive control.

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.

Process Evaluation of a School-Based High-Intensity Interval Training Program for Older Adolescents: The Burn 2 Learn Cluster Randomised Controlled Trial.

Process evaluations can help to optimise the implementation of school-based physical activity interventions. The purpose of this paper is to describe the process evaluation of a school-based high-intensity interval training (HIIT) program for older adolescent students, known as Burn 2 Learn (B2L). B2L was evaluated via a cluster randomised controlled trial in 20 secondary schools (10 intervention, 10 control) in New South Wales, Australia. Teachers (n = 22 (55% female)) from the 10 intervention schools, delivered the program over three phases (Phases 1 and 2, 6 months; Phase 3, 6 months) to older adolescent students (n = 337 (50% female); mean ± standard deviation (SD) age = 16.0 ± 0.4 years). Process evaluation data were collected across the 12-month study period. Teachers delivered 2.0 ± 0.8 and 1.7 ± 0.6 sessions/week in Phases 1 and 2 respectively (mean total 25.9 ± 5.2), but only 0.6 ± 0.7 sessions/week in Phase 3. Observational data showed that session quality was high, however heart rate (HR) data indicated that only half of the students reached the prescribed threshold of ≥85% predicted HRmax during sessions. Over 80% of teachers reported they intended to deliver the B2L program to future student cohorts. Almost 70% of students indicated they intended to participate in HIIT in the future. Teachers considered the program to be adaptable, and both students and teachers were satisfied with the intervention. B2L was implemented with moderate-to-high fidelity in Phases 1 and 2, but low in Phase 3. Our findings add to the relatively scant process evaluation literature focused on the delivery of school-based physical activity programs.

Time-efficient intervention to improve older adolescents' cardiorespiratory fitness: findings from the 'Burn 2 Learn' cluster randomised controlled trial.

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).

Feasibility of test administration and preliminary findings for cognitive control in the Burn 2 learn pilot randomised controlled trial.

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.

Review of High-Intensity Interval Training for Cognitive and Mental Health in Youth.

PURPOSE: High-intensity interval training (HIIT) has emerged as a time-efficient strategy to improve children's and adolescents' health-related fitness in comparison to traditional training methods. However, little is known regarding the effects on cognitive function and mental health. Therefore, the aim of this systematic review was to evaluate the effect of HIIT on cognitive function (basic information processing, executive function) and mental health (well-being, ill-being) outcomes for children and adolescents. METHODS: A systematic search was conducted, and studies were eligible if they 1) included a HIIT protocol, 2) examined cognitive function or mental health outcomes, and 3) examined children or adolescents (5-18 yr). Separate meta-analyses were conducted for acute and chronic studies, with potential moderators (i.e., study duration, risk of bias, participant age, cognitive demand, and study population) also explored. RESULTS: A total of 22 studies were included in the review. In acute studies, small to moderate effects were found for executive function (standardized mean difference [SMD], 0.50, 95% confidence interval [CI], 0.03-0.98; P = 0.038) and affect (SMD, 0.33; 95% CI, 0.05-0.62; P = 0.020), respectively. For chronic studies, small significant effects were found for executive function (SMD, 0.31; 95% CI, 0.15-0.76, P < 0.001), well-being (SMD, 0.22; 95% CI, 0.02-0.41; P = 0.029), and ill-being (SMD, -0.35; 95% CI, -0.68 to -0.03; P = 0.035). CONCLUSIONS: Our review provides preliminary review evidence suggesting that participation in HIIT can improve cognitive function and mental health in children and adolescents. Because of the small number of studies and large heterogeneity, more high-quality research is needed to confirm these findings.

Cardiorespiratory fitness, muscular fitness and mental health in older adolescents: A multi-level cross-sectional analysis.

Physical activity interventions that promote cardiorespiratory (CRF) and muscular fitness (MF) may improve mental health in young adolescents. However, less is known about the links between fitness and mental health in older adolescents, as they are an understudied population. In addition, the association between MF and adolescents' mental health is less clear than it is for CRF. Our primary aim was to investigate whether MF is independently associated with mental health in a sample of older adolescents. Our secondary aim was to determine if the association between fitness and mental health was moderated by sex, socio-economic status (SES) or weight status. Participants were 670 students (16.0 [0.4] years, 44.6% female) from 20 secondary schools in New South Wales, Australia. Mental health (well-being and internalizing problems) was self-reported using the Short Warwick-Edinburgh Mental Wellbeing Scale and the Strengths and Difficulties Questionnaire. We assessed CRF using the Progressive Aerobic Cardiovascular Endurance Run and MF using the push-up and standing long jump tests. After controlling for CRF, MF was not associated with mental health. CRF was associated with well-being (ß = 0.20, p < .001) and internalizing problems (ß = -0.27, p < .001). The strength of association between CRF and mental health was stronger in girls, than boys. No interaction effects were observed for SES or weight status. Although cross-sectional, our findings provide further evidence of the potential benefits of CRF for adolescents' mental health (i.e., well-being and internalizing problems), particularly girls. However, MF may be less relevant for mental health among this population.

School-based physical activity intervention for older adolescents: rationale and study protocol for the Burn 2 Learn cluster randomised controlled trial.

INTRODUCTION: This trial aims to investigate the impact of a school-based physical activity programme, involving high-intensity interval training (HIIT), on the physical, mental and cognitive health of senior school students. METHODS AND ANALYSIS: The Burn 2 Learn (B2L) intervention will be evaluated using a two-arm parallel group cluster randomised controlled trial with allocation occurring at the school level (to treatment or wait-list control). Schools will be recruited in two cohorts from New South Wales, Australia. The trial will aim to recruit ~720 senior school students (aged 16-18 years) from 20 secondary schools (ie, 10 schools per cohort). A range of implementation strategies will be provided to teachers (eg, training, equipment and support) to facilitate the delivery of HIIT sessions during scheduled classes. In phase I and II (3 months each), teachers will facilitate the delivery of at least two HIIT sessions/week during lesson-time. In phase III (6 months), students will be encouraged to complete sessions outside of lesson-time (teachers may continue to facilitate the delivery of B2L sessions during lesson-time). Study outcomes will be assessed at baseline, 6 months (primary end point) and 12 months. Cardiorespiratory fitness (shuttle run test) is the primary outcome. Secondary outcomes include: vigorous physical activity, muscular fitness, cognition and mental health. A subsample of students will (i) provide hair samples to determine their accumulated exposure to stressful events and (ii) undergo multimodal MRI to examine brain structure and function. A process evaluation will be conducted (ie, recruitment, retention, attendance and programme satisfaction). ETHICS AND DISSEMINATION: This study has received approval from the University of Newcastle (H-2016-0424) and the NSW Department of Education (SERAP: 2017116) human research ethics committees. TRIAL REGISTRATION NUMBER: ACTRN12618000293268; Pre-results.

Feasibility and Preliminary Efficacy of a Teacher-Facilitated High-Intensity Interval Training Intervention for Older Adolescents.

PURPOSE: This study was designed to assess the feasibility and preliminary efficacy of a teacher-facilitated high-intensity interval training intervention for older adolescents (ie, 16-18 y). METHODS: Two secondary schools from New South Wales, Australia were recruited, and participants (ie, grade 11 students; 16.2 [0.4] y) were randomized at the school level to the Burn 2 Learn intervention (n = 38), or a wait-list control group (n = 30). Teachers were trained to facilitate the delivery of the novel high-intensity interval training program, which involved 3 sessions per week (∼12-20 min) for 14 weeks. A range of process measures were used to assess intervention feasibility (ie, recruitment, retention, attendance, and program satisfaction). Primary (cardiorespiratory fitness, determined using the progressive aerobic cardiovascular endurance run shuttle run test) and secondary outcomes were assessed at baseline and posttest (14-wk). RESULTS: Sixty-eight grade 11 students were recruited at baseline (85% of target sample), 61 participants completed posttest assessments (90% retention) and on average, participants performed 1.9 sessions per week. Overall, teachers (4.0/5) and students (4.0/5) were satisfied with the Burn 2 Learn program. Group by time effects were observed for cardiorespiratory fitness (8.9 laps; 95% confidence intervals, 1.7-16.2) and a selection of secondary outcomes. CONCLUSION: This study provides evidence for the feasibility and preliminary efficacy of a teacher-facilitated high-intensity interval training intervention for older adolescents.