Search

Purpose: This systematic review aimed to identify studies evaluating the impact of high-intensity interval training when delivered in school and sports training. Methods: A systematic search of 10 databases (September 2019) identified 24 eligible studies (including children and/or adolescents 5–18 years and reporting cardiometabolic health and/or health-related fitness outcomes), assessed for quality using the Cochrane Risk of Bias Tool (version 2.0). Outcomes were synthesized using a random-effects meta-analysis, and potential moderators were explored (i.e., study duration, risk of bias, age, and deliverer/instructor). Results: Standardized mean difference for the effects of high-intensity interval training were significant for body mass index g = −0.27 (p g = 0.27 (p g = 0.49 (p = .005), and upper body muscular fitness g = 0.37 (p = .002); but not for blood pressure (p > .05). Risk of bias results were variable (low = 8, some concerns = 9, and high = 7). Conclusion: Our findings suggest that embedding high-intensity interval training in schools and sports training can facilitate improvements in some aspects of cardiometabolic health and fitness in children and adolescents.

Objectives Participation in physical activity can improve mental health and well-being, but effects are mixed. This consensus statement from Sports Medicine Australia and the Australian Psychological Society aims to provide guidance to practitioners on the ways that physical activity can be promoted to maximise benefits to mental health. Method Following the Clinical Consensus Statement protocol, an expert group comprised of eight members with expertise in physical activity and mental health articulated recommendations regarding five physical activity contextual factors: type, physical environment, delivery, domain, and social environment. Results To optimise the mental health benefits of physical activity, we recommend: i) activity selection be guided by factors associated with adherence and enjoyment as opposed to any specific type (type); ii) facilitators (i.e., teachers, coaches, instructors, practitioners) deliver organised physical activity sessions using an instructional style that satisfies individuals' basic needs for autonomy, competence and social connection (delivery); iii) participation in physical activity with others who provide support, facilitate positive interactions, or make people feel valued, so long as it does not undermine a preference to be active alone (social environment); iv) where possible and appropriate, some physical activity should be undertaken outside in pleasant natural environments (physical environment); and, v) at least some physical activity be undertaken during leisure-time or via active travel, where possible prioritising activities one personally chooses to undertake (domain). Conclusions The type, domain, physical and social environment of physical activity, as well as the way in which it is delivered, will determine mental health outcomes. Practitioners can use these recommendations to optimise the effects of physical activity on mental health. peerReviewed

Schools are key settings for the promotion of students' physical activity, fitness, and motor competence. The purpose of our study was to investigate the efficacy of a 5-month-long intervention program that aimed to increase students' motor competence and health-related fitness during school days. We conducted a quasi-experimental study with 325 Finnish Grade 5 (Mage = 11.26, SD = 0.33) students from five schools. Two schools were allocated to the intervention group and three schools to the control group. The intervention consisted of three components: (a) weekly 20 min session during regular PE lessons, (b) weekly 20 min session during recess, and (c) daily 5-minute-long classroom activity breaks. All activities were designed to systematically develop different elements of motor competence and fitness. The following assessments were conducted at baseline and 5-months: cardiorespiratory fitness levels were measured by 20-meter shuttle run test, muscular fitness by curl-up and push-up tests, and motor competence by 5-leaps and throwing–catching combination tests. We analyzed the data using a multi-group latent change score modeling. Results showed that students in the intervention group developed significantly better in 20-meter shuttle run test (β = 0.269, p = 0.000, 95% CI [0.141, 0.397]; +5.0 laps), push-up (β = 0.442, p = 0.000, 95% CI [0.267, 0.617]; +6.5 repetitions), curl-up (β = 0.353, p = 0.001, 95% CI [0.154, 0.552]; +7.8 repetitions), and throwing–catching combination tests (β = 0.195, p = 0.019, 95% CI [0.033, 0.356]; +1.1 repetitions) than students in the control group. The intervention program appeared to be feasible and effective in increasing students' cardiorespiratory fitness, muscular fitness, and object control skills. This indicates that guided school-based physical activity programs can be influential in promoting physical fitness and motor competence among early adolescent students. peerReviewed

Background: The COVID-19 global pandemic greatly impacted lifestyles and physical activity routines. This study explored how the COVID-19 pandemic impacted participant experience and motivation in ecofit, a large, community-based, multicomponent intervention that supports aerobic and resistance-based physical activity using publicly available, outdoor exercise facilities and smartphone technology. Methods: Fifteen participants from the intervention arm of the study were interviewed. Audiotaped telephone interviews were transcribed verbatim and analyzed by a researcher uninvolved in the intervention. Through an inductive thematic approach, data were coded and organized into themes. The quantitative measure of participant smartphone application engagement was used as a classification during analysis. Results: Several themes representing participants’ experience of the COVID-19 pandemic in their engagement with ecofit, overall physical activity levels, motivation to exercise, and perception and usage of outdoor gym facilities were identified. Conclusion: The impact of the COVID-19 pandemic on clinical trials is beginning to emerge. Although the present study showed a mixed impact of the pandemic on participation in the ecofit program, the overall implications for the intervention are yet to be determined. Interestingly, although a large review found a negative impact of COVID-19 on physical activity, this sample reported an overall increase.

High-intensity interval training (HIIT) has become a polarizing form of exercise. In this article, we argue that adolescent HIIT programs can have population health impact if they are (i) integrated into existing opportunities, (ii) designed to develop physical literacy, (iii) delivered in an engaging manner, and (iv) guided and supported by an implementation framework that addresses relevant barriers and facilitators.

Background The primary aim of this pilot study was to evaluate the feasibility and preliminary efficacy of a school-based health and well-being program (Health and Well-being for Girls: HWBG) on adolescent girls’ well-being, mindfulness, screen-time, and physical activity. Method The HWBG program was evaluated using a group randomized controlled trial (RCT) in one secondary school. A convenience sample of female students in Grade 8 (mean age 14 ± 0.5 years) was recruited for the study (n=4 classes; 89 girls). The 20-week multi-component HWBG program, guided by Self-Determination Theory and Acceptance and Commitment Therapy, was designed and delivered by a member of the research team. Randomization occurred prior to baseline assessments at the class level (n=4 classes) into dose-matched treatment conditions (i.e., two classes received the HWBG intervention and two classes received an alternate elective course as a wait-list control group). Process evaluation measures of recruitment, retention, adherence, and satisfaction were used to determine program feasibility. This study was designed to assess feasibility (primary outcome) and preliminary efficacy (secondary outcomes), rather than effectiveness. Preliminary efficacy of HWBG for improving mental and social health, screen-time, and physical activity were measured and analyzed using linear mixed-models. Results “The health and well-being program” targeting adolescent girls was found to be feasible for implementation as an elective course in a secondary school setting. Participants in the HWBG program reported high levels of satisfaction, the majority of lessons (45 out of 50), were implemented as planned and adherence to the planned HWBG program content was very high. Medium positive effects on mental health (d=0.45) and social health (d=0.50) were observed. Small effects were observed for physical activity, and no significant intervention effects were found for levels of recreational screen time. Participant ratings showed high levels of perceived benefit and enjoyment as indicated in the evaluation data (mean rating of 4.44 out of a possible 5.0) when asked whether the program was enjoyable. Conclusion The study provides preliminary support for HWBG as a potentially feasible and enjoyable program suitable for use with adolescent girls in the secondary school setting. Potential of the study for facilitating improvements in pro-social and psychological well-being is also supported. Trial registration ACTRN12617000157370. The trial was registered with the Australian New Zealand Clinical Trials Registry.

Abstract Background In 2018, the Australian Government updated the Australian Physical Activity and Sedentary Behaviour Guidelines for Children and Young People. A requirement of this update was the incorporation of a 24-hour approach to movement, recognising the importance of adequate sleep. The purpose of this paper was to describe how the updated Australian 24-Hour Movement Guidelines for Children and Young People (5 to 17 years): an integration of physical activity, sedentary behaviour and sleep were developed and the outcomes from this process. Methods The GRADE-ADOLOPMENT approach was used to develop the guidelines. A Leadership Group was formed, who identified existing credible guidelines. The Canadian 24-Hour Movement Guidelines for Children and Youth best met the criteria established by the Leadership Group. These guidelines were evaluated based on the evidence in the GRADE tables, summaries of findings tables and recommendations from the Canadian Guidelines. We conducted updates to each of the Canadian systematic reviews. A Guideline Development Group reviewed, separately and in combination, the evidence for each behaviour. A choice was then made to adopt or adapt the Canadian recommendations for each behaviour or create de novo recommendations. We then conducted an online survey (n=237) along with three focus groups (n=11 in total) and 13 key informant interviews. Stakeholders used these to provide feedback on the draft guidelines. Results Based on the evidence from the Canadian systematic reviews and the updated systematic reviews in Australia, the Guideline Development Group agreed to adopt the Canadian recommendations and, apart from some minor changes to the wording of good practice statements, maintain the wording of the guidelines, preamble, and title of the Canadian Guidelines. The Australian Guidelines provide evidence-informed recommendations for a healthy day (24-hours), integrating physical activity, sedentary behaviour (including limits to screen time), and sleep for children (5-12 years) and young people (13-17 years). Conclusions To our knowledge, this is only the second time the GRADE-ADOLOPMENT approach has been used to develop movement behaviour guidelines. The judgments of the Australian Guideline Development Group did not differ sufficiently to change the directions and strength of the recommendations and as such, the Canadian Guidelines were adopted with only very minor alterations. This allowed the Australian Guidelines to be developed in a shorter time frame and at a lower cost. We recommend the GRADE-ADOLOPMENT approach, especially if a credible set of guidelines that was developed using the GRADE approach is available with all supporting materials. Other countries may consider this approach when developing and/or revising national movement guidelines.

Background The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts. Objective This study aimed to produce a list of the top 10 international priorities for research and surveillance on physical fitness among children and adolescents. Methods Using a twin-panel Delphi method, two independent panels consisting of 46 international experts were identified (panel 1 = 28, panel 2 = 18). The panel participants were asked to list up to five priorities for research or surveillance (round 1), and then rated the items from their own panel on a 5-point Likert scale of importance (round 2). In round 3, experts were asked to rate the priorities identified by the other panel. Results There was strong between-panel agreement (panel 1: rs = 0.76, p rs = 0.77, p Conclusions The priorities identified in this study provide guidance for future international collaborations and research efforts on the physical fitness of children and adolescents over the next decade and beyond.

Purpose The purpose of this research was to develop, implement, and test the efficacy of a theory-driven, evidence-informed peer leadership program for elementary school students (Grade 6 and 7; age 11–12 years) and the Grade 3/4 students with whom they were partnered. The primary outcome was teacher ratings of their Grade 6/7 students’ transformational leadership behaviors. Secondary outcomes included: Grade 6/7 students’ leadership self-efficacy, as well as Grade 3/4 motivation, perceived competence, general self-concept, fundamental movement skills, school-day physical activity, and program adherence, and program evaluation. Methods We conducted a two-arm cluster randomized controlled trial. In 2019, 6 schools comprising 7 teachers, 132 leaders, and 227 grade 3 and 4 students were randomly allocated to the intervention or waitlist control conditions. Intervention teachers took part in a half-day workshop (January 2019), delivered 7 x 40 minute lessons to Grade 6/7 peer leaders (February and March 2019), and these peer leaders subsequently ran a ten-week physical literacy development program for Grade 3/4 students (2x30 minutes sessions per week). Waitlist-control students followed their usual routines. Assessments were conducted at baseline (January 2019) and immediately post-intervention (June 2019). Results The intervention had no significant effect on teacher ratings of their students’ transformational leadership (b = 0.201, p = .272) after controlling for baseline and gender. There was no significant condition effect for Grade 6/7 student rated transformation leadership (b = 0.077, p = .569) or leadership self-efficacy (b = 3.747, p = .186) while controlling for baseline and gender. There were null findings for all outcomes related to Grade 3 and 4 students. Discussion Adaptions to the delivery mechanism were not effective in increasing leadership skills of older students or components of physical literacy in younger Grade 3/4 students. However, teacher self-reported adherence to the intervention delivery was high. Trial registration This trial was registered on December 19th, 2018 with Clinicaltrials.gov (NCT03783767), https://clinicaltrials.gov/ct2/show/NCT03783767.

Background Physical Activity 4 Everyone (PA4E1) is an evidence-based program effective at increasing adolescent physical activity (PA) and improving weight status. This study aimed to determine a) the effectiveness of an adapted implementation intervention to scale-up PA4E1 at 24-month follow-up, b) fidelity and reach, and c) the cost and cost-effectiveness of the implementation support intervention. Methods A cluster randomised controlled trial using a type III hybrid implementation-effectiveness design in 49 lower socio-economic secondary schools, randomised to a program (n = 24) or control group (n = 25). An adapted implementation intervention consisting of seven strategies was developed to support schools to implement PA4E1 over 24-months. The primary outcome was the proportion of schools implementing at least four of the 7 PA practices, assessed via computer assisted telephone interviews (CATI) with Head Physical Education Teachers. Secondary outcomes included the mean number of PA practices implemented, fidelity and reach, cost and cost-effectiveness. Logistic regression models assessed program effects. Results At baseline, no schools implemented four of the 7 PA practices. At 24-months, significantly more schools in the program group (16/23, 69.6%) implemented at least four of the 7 PA practices than the control group (0/25, 0%) (p P 75%). The total cost of the program was $415,112 AUD (2018) ($17,296 per school; $117.30 per student). Conclusions The adapted implementation intervention provides policy makers and researchers with an effective and potentially cost-effective model for scaling-up the delivery of PA4E1 in secondary schools. Further assessment of sustainability is warranted. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12617000681358 prospectively registered 12th May 2017.

The relationship between physical activity (PA) intensity and executive functions in older adolescents remain 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.We analyzed baseline data from 418 participants (211 females, MAfter 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 related to attentional control or working memory.Our findings reveal a novel association between higher-intensity PA and superior attentional control among adolescent girls.

Physical fitness is an important marker of current and future health status, yet the association between physical fitness and indicators of mental health in youth has not been systematically reviewed and meta-analyzed. The aim of this work was to systematically review and meta-analyze the association between physical fitness components (i.e. cardiorespiratory fitness, muscular fitness, speed-agility, flexibility and fitness composite) and mental health indicators (i.e. psychological well-being and psychological ill-being) in preschoolers, children and adolescents. Systematic review and meta-analysis. Systematic searches were conducted in PubMed, Web of Science and Scopus from database inception to May 2020. Studies (cross-sectional, longitudinal and intervention designs) were included if they measured at least one physical fitness component and one mental health indicator in healthy youth (2–18 years). A total of 58 unique studies (52 cross-sectional, 4 longitudinal and 4 intervention studies) met all eligibility criteria and were included. There was a significant positive overall association between physical fitness and mental health in children and adolescents (pooled r = 0.206, p

ObjectiveTo 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.DesignA systematic review and meta-analysis.Data sourcesStudies from electronic databases from inception to 3 January 2021 were identified.Eligibility criteria for selecting studiesExperimental 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.Results19 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; I2=83.70%), mainly in primary education settings (g=0.48, 95% CI 0.07 to 0.89; I2=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; I2=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; I2=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; I2=48.48%). Finally, there were no differences between the three PE interventions (ie, quantity, quality, and combined PE interventions) in regard to academic performance.ConclusionImproving 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.

Organized sport is a context in which to promote positive youth development (PYD). Interventions with a PYD lens are often implemented to promote a wide range of physical or psychosocial benefits t...

Highlights • Cardiorespiratory fitness was associated with older adolescents’ cognitive control. • Muscular fitness was not associated with older adolescents’ cognitive control. • Cardiorespiratory fitness selectively influences cognition in late adolescence., 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., Graphical Abstract Image, graphical abstract

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 Physical inactivity is a preventable risk factor for several chronic diseases and one of the driving forces behind the growing global burden of disease. Recent evidence has shown that interventions using mobile smartphone applications (apps) can promote a significant increase in physical activity (PA) levels. However, the accuracy and reliability of using apps is unknown. OBJECTIVE The aim of our review is to determine the accuracy and reliability of using mobile apps to measure PA levels in young people. We conducted a systematic review guided by PRISMA. METHODS Studies published from 2007 to 2020 were sourced from eight databases (Ovid MEDLINE, Embase (Elsevier), Cochrane Library (Wiley), PsychINFO (EBSCOhost), CINAHL (EBSCOHost), Web of Science (Clarivate), SPORTDiscus (EBSCOhost), and IEEE Xplore Digital Library database). Studies conducted in young people, aged 10-24 years without chronic illness that evaluated a mobile app’s ability to measure PA. Primary outcomes include validity, reliability and/or responsiveness of the measurement approach. Duplicate screening was conducted for eligibility, data extraction and assessing the risk of bias. Results are reported as a systematic review. The main outcome measures assessed were: total PA time (mins/day or mins/week), total moderate-vigorous PA per week, daily step count, intensity measure (heart rate), and frequency measure (days per week). RESULTS Of the 149 identified studies, five met inclusion criteria (n=322 participants, 58% female; mean age 14±3 years). Three studies measured criterion validity and compared PA measured via apps against an Actigraph accelerometer. The two studies that reported on construct validity reported a significant difference between self-reported PA and the objective measure. Only one of the five apps examined is available to the public, and though this app was highly accepted by young people, the app recorded PA to be significantly different to participants’ self-reported PA. CONCLUSIONS Overall, few studies assess the reliability, validity and responsiveness of mobile apps to measure PA in healthy young people, with studies typically only reporting on one measurement property. Of the three studies that measured validity, all concluded mobile phones to be an acceptable and valid tool. More research is needed into the validity and reliability of smart-phone apps to measure PA levels in this population, as well as populations with other characteristics, including age groups and those with chronic disease. CLINICALTRIAL Systematic review registration: PROSPERO CRD42019122242.

Background: The construct of physical literacy is gaining traction internationally and yet measurement of physical literacy is in its infancy. This paper describes the development of a pictorial child report scale of perceived physical literacy based on the comprehensive Australian Physical Literacy Framework, which includes 30 elements within four domains (physical, psychological, cognitive and social). Methods: An expert reference committee with academic and industry representatives from physical education, sport and education was formed to provide input to each stage of the process. Qualitative research methods were used to (a) determine a character that was gender neutral, not representative of a particular race or ethnicity and appealing to children, and (b) the content (i.e. relationship between item images, wording and format with the intended construct) and response processes (i.e. interpretation of items) of the Physical Literacy in Children Questionnaire (PL-C Quest). A total of 17 children aged 4–12 years were interviewed as part of the study. Results: A ‘bunny’ character was preferred by children. Overall, children interpreted most images as intended by the researchers, and, in many cases, without having to hear the words that went with the images. Some of the image scenarios were amended and redrawn according to the suggestions received from children and the expert reference group. Discussion: This study has provided qualitative evidence based on the content of the PL-C Quest elements and domains, on the ways respondents understand, and interpret the items. This is the first step towards the development and testing of a pictorial instrument to comprehensively measure children’s self-perceived physical literacy. Refereed/Peer-reviewed

Most family-based physical activity interventions have been modestly successful and failed to engage fathers. Also, program impact on family functioning and psychosocial outcomes are rarely measured. We explored the impact of an innovative father–daughter physical activity program on family functioning and psychosocial outcomes for girls using qualitative methods. Of the 115 fathers who participated in the ‘Dads And Daughters Exercising and Empowered’ (DADEE) pilot study, a random sample (stratified by baseline physical activity status) of 23 fathers (mean (SD) age: 41.4 (4.8) years) participated in semi-structured telephone interviews. Audio recordings were transcribed and analyzed by an independent researcher using a mixed inductive and deductive thematic approach. Seven themes were identified highlighting improvements in: (i) daughters’ social-emotional well-being, (ii) father involvement and engagement with their daughter, (iii) fathers’ parenting skills, (iv) the father–daughter relationship, (v) co-parenting, (vi) family relationship dynamics, and (vii) knowledge and understanding of gender stereotypes and gender bias. A number of strategies were also identified as to how the program improved these outcomes. Engaging fathers and daughters in physical activity programs may have substantive benefits for daughters’ mental health as well as broader outcomes for fathers and families. Enhancing fathers’ and daughters’ knowledge and skills through evidence-based strategies may be a useful approach to optimize the well-being of families.

The purpose of this study was to assess the feasibility and preliminary efficacy of a high-intensity interval training (HIIT) intervention integrated into the workplace on physical and mental health outcomes in a sample of adults. The Work-HIIT intervention was evaluated at the University of Newcastle (March-July 2019). University employees (18+ years) who self-identified as predominantly sedentary at work (n = 47, 43.0 ± 10.7 years; 41 female) were recruited, screened, and randomized after baseline assessments into Work-HIIT (n = 24) or wait-list control (n = 23) conditions. Participants were asked to attend 2-3 researcher-facilitated HIIT sessions/week (weeks 1-8). Sessions included a 2-minute gross-motor warm-up, followed by various combinations of aerobic and muscular fitness exercises lasting 8 minutes (using 30:30 second work: rest intervals). Program feasibility was assessed using measures of satisfaction, compliance, adherence, fidelity, and retention. Physiological and psychological outcomes were measured at baseline and 9 weeks. Feasibility data were investigated using descriptive statistics and efficacy outcomes determined using linear mixed models and Cohen's d effect sizes. Participant ratings showed high levels of satisfaction (4.6/5); 71% of participants attended ≥2 sessions/wk and averaged 85.9% HRmax across all sessions (including rest and work intervals). Small-to-medium positive effects resulted for cardiorespiratory fitness [+2.9 laps, 95% CI (-4.19-10.14); d = 0.34] and work productivity [+0.26, d = 0.47]. Large positive effects resulted for muscular fitness [push-ups +3.5, d = 0.95; standing jump +10.1 cm, d = 1.12]; HIIT self-efficacy [+16.53, d = 1.57]; sleep [weekday +0.76 hours, d = 1.05]; and autonomous motivation [+0.23, d = 0.76]. This study supports the feasibility and preliminary efficacy of facilitator-led Work-HIIT as a time-efficient, enjoyable, and convenient workplace exercise option for adults.

Background Six core behavioural risk factors (poor diet, physical activity, sedentary behaviour, alcohol misuse, smoking and unhealthy sleep patterns) have been identified as strong determinants of chronic disease, such as cardiovascular disease, diabetes and cancers. Smartphones have the potential to provide a real-time, pervasive, unobtrusive and cost-effective way to measure health behaviours and deliver instant feedback to users. Despite this, validity of using smartphones to measure these six key behaviours is largely unknown. The proposed systematic review aims to address this gap by identifying existing smartphone-based approaches to measure these health behaviours and critically appraising, comparing and summarizing the quality of their measurement properties. Methods A systematic search of the Ovid MEDLINE, Embase (Elsevier), Cochrane Library (Wiley), PsychINFO (EBSCOhost), CINAHL (EBSCOHost), Web of Science (Clarivate), SPORTDiscus (EBSCOhost) and IEEE Xplore Digital Library databases will be conducted from January 2007 to March 2020. Eligible studies will be those written in English that measure at least one of the six health behaviours of interest via a smartphone and report on at least one measurement property. The primary outcomes will be validity, reliability and/or responsiveness of these measurement approaches. A secondary outcome will be the feasibility (e.g. user burden, usability and cost) of identified approaches. No restrictions will be placed on the participant population or study design. Two reviewers will independently screen studies for eligibility, extract data and assess the risk of bias. The study methodological quality (or bias) will be appraised using an appropriate tool. Our results will be described in a narrative synthesis. If feasible, random effects meta-analysis will be conducted where appropriate. Discussion The results from this review will provide important information about the types of smartphone-based approaches currently available to measure the core behavioural risk factors for chronic disease and the quality of their measurement properties. It will allow recommendations on the most suitable and effective measures of these lifestyle behaviours using smartphones. Valid and reliable measurement of these behaviours and risk factor opens the door to targeted and real-time delivery of health behaviour interventions, providing unprecedented opportunities to offset the trajectory toward chronic disease. Systematic review registration PROSPERO: CRD42019122242

Objectives: Examining mediators of intervention efficacy in an m-health intervention targeting physical activity and sleep in 160 Australian adults.Design: Nationwide randomised controlled trial.Ma...

The population of adults living with congenital heart disease (CHD) has grown rapidly in recent decades due to major advances in surgical and medical care. Although the benefits of physical activity (PA) and exercise are well recognised in the management of chronic diseases, the therapeutic role of exercise for the CHD population has been under-studied and under-recognised. In fact, people living with complex CHD have traditionally been advised against participation in moderate or vigorous PA due to safety concerns. However, a small but growing body of literature has demonstrated that PA and exercise are safe and beneficial for the vast majority of people with CHD following appropriate screening. Exercise training (ET) is a potent therapy to improve well-being and cardiorespiratory fitness, which likely has important implications for prognosis. This has led to ET becoming an increasingly important adjunct to medical therapy in the management of this group who frequently have significant exercise limitation and complex medical issues. However, there is currently limited evidence-based guidance that has been published regarding appropriate exercise prescription in adults with CHD. This article aims to provide an overview of different congenital heart conditions, their impact on the exercise response, and to provide considerations and recommendations for ET in adolescents and adults living with CHD based on the available literature.

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.

Background A healthy lifestyle program that appeals to, and supports, obese New Zealand (NZ) European, Māori (indigenous) and Pasifika men to achieve weight loss is urgently needed. In Scotland, Football Fans in Training (FFIT), a weight management and healthy lifestyle program for overweight and obese men aged 35–65 years , delivered by community coaching staff at professional football clubs, has been shown to be beneficial and cost-effective. A pilot program inspired by FFIT but delivered by professional rugby clubs in NZ (n = 96) was shown to be effective in weight loss, improved physiological outcomes, and adherence to healthy lifestyle behaviors in overweight and obese men. The objective of this trial is to determine the effectiveness and cost-effectiveness of the Rugby Fans in Training New Zealand (RUFIT-NZ) program. Methods A pragmatic, two-arm, multi-center, randomized controlled trial involving 308 overweight and obese men aged 30–65 years, randomized to either an intervention group (n = 154) or a wait-list control group (n = 154). The intervention-group participated in the 12-week RUFIT-NZ program, a gender-sensitized, healthy lifestyle intervention adapted to the environment and cultural diversity of NZ and delivered through professional rugby clubs. Participants in the intervention group undergo physical training sessions, in addition to workshop-based sessions to learn about nutrition, physical activity, sleep, sedentary behavior, and a range of behavior-change strategies for sustaining a healthier lifestyle. The control group receives the program after 52 weeks. The primary outcome is change in body weight from baseline to 52 weeks. Secondary outcomes include change in body weight at 12 weeks; waist circumference, blood pressure, fitness, and lifestyle behaviors at 12 and 52 weeks; and cost-effectiveness. A process evaluation informed by the RE-AIM framework will evaluate potential implementation of RUFIT-NZ as an ongoing program in NZ after the trial. Discussion This trial will investigate the effectiveness and cost-effectiveness of the RUFIT-NZ program in overweight and obese NZ men. Trial registration Australia New Zealand Clinical Trials Registry, ACTRN12619000069156. Registered on 18 January 2019, according to the World Health Organization Trial Registration Data Set. Universal Trial Number, U1111-1245-0645.

IntroductionPersistent 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 synthesize evidence focused on the mechanisms through which physical activity might reduce psychiatric symptoms across all ages.Methods and analysisWith 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 disseminationOnly data that has 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 (e.g., through regular channels, including social media).PROSPERO registration numberCRD42021239440Strengths and limitations of this studyThis protocol has been designed according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses for Protocols (PRISMA-P) guidelines and guidelines of the Cochrane Effective Practice and Organisation of Care.This protocol presents a cautiously designed search strategy, inclusion and exclusion criteria, and timespan and age-range coverage.A possible limitation is that included studies might be heterogeneous in the study design, data collection methods, and data analysis which might limit the ability to synthesize the results using a meta-analysis.The value of this systematic review depends on the quality and availability of the evidence on the topic.

IntroductionPhysical 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 analysisWe 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 disseminationThis 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 numberAustralian New Zealand Clinical Trials Registry Number: ACTRN12621000884808.

Aim: Participation in classroom physical activity breaks may improve children’s cognition, but few studies have involved adolescents. The primary aim of this study was to examine the effects of classroom-based resistance training with and without cognitive training on adolescents’ cognitive function.Methods: Participants were 97 secondary school students (45.4% females, mean age 15.78 ± 0.44). Four-year 10 classes from one school were included in this four-arm cluster randomized controlled trial. Classes were randomly assigned to the following groups: sedentary control with no cognitive training, sedentary with cognitive training, resistance training without cognitive training, and resistance training with cognitive training. Sessions varied in levels of both cognitive demand and resistance training (i.e., high vs. low) and were administered three times per week for 4 weeks (12 sessions). Inhibition, cognitive flexibility, episodic memory, on-task behavior, and muscular fitness were assessed at baseline and post-test. Linear mixed models were used to examine changes within and between groups.Results: In comparison with the control group, episodic memory improved significantly in the resistance training without cognitive training group (−9.87 units, 95% CI: −17.71 to −2.03, p = 0.014, d = 0.72). There were no group-by-time effects for inhibition or cognitive flexibility. Classroom activity breaks both with and without cognitive demand improved participants’ on-task behavior in comparison with the control and sedentary group. The resistance training programs did not lead to improvements in muscular fitness.Conclusion: Participation in body weight resistance training without cognitive training led to selective improvements in episodic memory. No training effects were found for inhibition or cognitive flexibility. A longer study period may be necessary to induce improvements in muscular fitness and associated changes in inhibition and cognitive flexibility.Clinical Trial Registration:https://www.anzctr.org.au/ACTRN12621001341819.aspx, Australian New Zealand Clinical Trials Registry—ACTRN12621001341819.

Background: Achieving system-level, sustainable ‘scale-up’ of interventions is the epitome of successful translation of evidence-based approaches in population health. In physical activity promotion, few evidence-based interventions reach implementation at scale or become embedded within systems for sustainable health impact. This is despite the vast published literature describing efficacy studies of small-scale physical activity interventions. Research into physical activity scale-up (through case-study analysis; evaluations of scale-up processes in implementation trials; and mapping the processes, strategies, and principles for scale-up) has identified barriers and facilitators to intervention expansion. Many interventions are implemented at scale by governments but have not been evaluated or have unpublished evaluation information. Further, few public health interventions have evaluations that reveal the costs and benefits of scaled-up implementation. This lack of economic information introduces an additional element of risk for decision makers when deciding which physical activity interventions should be supported with scarce funding resources. Decision-makers face many other challenges when scaling interventions which do not relate to formal research trials of scale-up; Methods: To explore these issues, a multidisciplinary two-day workshop involving experts in physical activity scale-up was convened by the University of Newcastle, Australia, and the University of Ottawa, Canada (February 2019); Results: In this paper we discuss some of the scale-up tensions (challenges and conflicts) and paradoxes (things that are contrary to expectations) that emerged from this workshop in the context of the current literature and our own experiences in this field. We frame scale-up tensions according to epistemology, methodology, time, and partnerships; and paradoxes as ‘reach without scale’, ‘planned serendipity’ and ‘simple complexity’. We reflect on the implications of these scale-up tensions and paradoxes, providing considerations for future scale-up research and practice moving forward; Conclusions: In this paper, we delve deeper into stakeholders’ assumptions, processes and expectations of scaling up, and challenge in what ways as stakeholders, we all contribute to desired or undesired outcomes. Through a lens of ‘tensions’ and ‘paradoxes’, we make an original contribution to the scale-up literature that might influence current perspectives of scaling-up, provide future approaches for physical activity promotion, and contribute to understanding of dynamic of research-practice partnerships.

Background: Despite developments in surgical techniques and medical care, people with a Fontan circulation still experience long-term complications; non-invasive therapies to optimize the circulation have not been established. Exercise intolerance affects the majority of the population and is associated with worse prognosis. Historically, people living with a Fontan circulation were advised to avoid physical activity, but a small number of heterogenous, predominantly uncontrolled studies have shown that exercise training is safe—and for unique reasons, may even be of heightened importance in the setting of Fontan physiology. The mechanisms underlying improvements in aerobic exercise capacity and the effects of exercise training on circulatory and end-organ function remain incompletely understood. Furthermore, the optimal methods of exercise prescription are poorly characterized. This highlights the need for large, well-designed, multi-center, randomized, controlled trials.Aims and Methods: The Fontan Fitness Intervention Trial (F-FIT)—a phase III clinical trial—aims to optimize exercise prescription and delivery in people with a Fontan circulation. In this multi-center, randomized, controlled study, eligible Fontan participants will be randomized to either a 4-month supervised aerobic and resistance exercise training program of moderate-to-vigorous intensity followed by an 8-month maintenance phase; or usual care (control group). Adolescent and adult (≥16 years) Fontan participants will be randomized to either traditional face-to-face exercise training, telehealth exercise training, or usual care in a three-arm trial with an allocation of 2:2:1 (traditional:telehealth:control). Children (

This trial aims to investigate the effects of the ActTeens physical activity program, on adolescents’ physical activity level, health-related fitness, cardiometabolic and mental health. The trial will aim to recruit ~140 adolescents (aged 13–14 years). Participants will be randomized into either intervention or control groups. The intervention will be guided by social cognitive theory and self-determination theory and implemented over one school term (24-weeks). The ActTeens Program will include: (1) structured physical activity sessions delivered within physical education, including movement-based games and dynamic stretching warm-ups; resistance training skill development; high-intensity training workouts; and cool-downs; (2) self-monitoring plus goal setting for physical activity by pedometer-smart wearable; and (3) healthy lifestyle guidance (social support) by WhatsApp® messages about healthy eating and regular physical activity for the intervention and parents groups. Study outcomes will be assessed at baseline, 24-weeks from baseline, and 12-months from baseline. Physical activity (accelerometer) is the primary outcome. Secondary outcomes include muscular and cardiorespiratory fitness, cardiometabolic profile, and mental health. A process evaluation will be conducted (i.e., recruitment, retention, attendance, and program satisfaction). This project will have the potential to address many questions and debates regarding the implementation of physical activity interventions in low-and- middle-income countries. Trial registration: ClinicalTrials.gov NCT05070377. Registered on 7 October 2021.

Funder: Sue and Bob O'Donnell, Summary: Biases introduced in early���stage studies can lead to inflated early discoveries. The risk of generalizability biases (RGBs) identifies key features of feasibility studies that, when present, lead to reduced impact in a larger trial. This meta���study examined the influence of RGBs in adult obesity interventions. Behavioral interventions with a published feasibility study and a larger scale trial of the same intervention (e.g., pairs) were identified. Each pair was coded for the presence of RGBs. Quantitative outcomes were extracted. Multilevel meta���regression models were used to examine the impact of RGBs on the difference in the effect size (ES, standardized mean difference) from pilot to larger scale trial. A total of 114 pairs, representing 230 studies, were identified. Overall, 75% of the pairs had at least one RGB present. The four most prevalent RGBs were duration (33%), delivery agent (30%), implementation support (23%), and target audience (22%) bias. The largest reductions in the ES were observed in pairs where an RGB was present in the pilot and removed in the larger scale trial (average reduction ES ���0.41, range ���1.06 to 0.01), compared with pairs without an RGB (average reduction ES ���0.15, range ���0.18 to ���0.14). Eliminating RGBs during early���stage testing may result in improved evidence.

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.

Background The development of physical literacy (PL) early in life may influence children's subsequent physical activity (PA) participation and consequent health benefits across the life course. Interventions designed for parents are lacking, but such efforts can potentially enhance the PL of parents and their children’s PA participation. Additionally, there is insufficient evidence to support the feasibility of delivering a PL intervention using an online format. Therefore, the purpose of this study was to examine the feasibility and effectiveness of a parent-focused, theory-driven, online-delivered intervention designed to improve the parents’ PL and children’s PA behaviors. Methods A non-randomized trial was conducted to evaluate the effects of the program. 224 Hong Kong families (primary school-aged children and their parents) registered to the program were considered the experimental group and were exposed to an online intervention over three months. Another 220 families in Hong Kong were considered the comparison group and did not receive any intervention. Outcome measures included PA behaviors (daily steps and moderate-to-vigorous PA), parent–child co-activity behaviors, family PA routines, and parent perceived PL. Linear mixed models were used to analyze the differences in terms of changes in measured outcomes between groups over time. Results No significant group-by-time effects were found for children’s or parents’ PA behaviors. In terms of the family Co-PA routines, a small positive effect size in favor of the experimental group was found (p = .44, d = 0.2). Group-by-time effects favorable to the experimental group was detected for parent–child co-activity (p d = 0.7) and parental PL (p d = 0.9) at post-intervention. The results demonstrated that the intervention was acceptable and that there was potential for scale up. Conclusions Findings indicated that the intervention was effective in increasing parent–child co-activity and parent perceived PL. During the pandemic, online intervention delivery was found to be feasible. Using this mode of delivery, the intervention has the potential to reach a wide population in the local context. Trial registration The study was prospectively registered at the Chinese Clinical Trial Registry, Registration number: ChiCTR2100041903, Registered 09 January 2021.

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.

Background Physical inactivity, poor diet, sedentary recreational screen time, poor sleep, alcohol use and smoking (the “Big 6”) are key lifestyle risk factors for chronic disease. The Big 6 typically emerge during adolescence, co-occur and continue into adulthood. To improve short- and long-term health, early and effective prevention is critical. Methods A cluster randomised controlled trial (ACTRN12619000431123) is being conducted in 71 schools across NSW, QLD and WA. Schools are randomised to the Health4life intervention or health education as usual. The intervention has three components: 1) An online, school-based program delivered to all Year 7 students; 2) An accompanying smartphone application (all students); 3) Booster content, delivered to at-risk students in Years 8 and 9. Students complete questionnaires on five occasions over three years. Results Preliminary analyses including 6716 students (49% female) indicated that 22% of participants met national guidelines for physical activity, 27% reported drinking 2+ cups of sugar-sweetened beverages/week, 3% had consumed a standard alcoholic drink in the prior 6 months, 2% had tried smoking, 86% engaged in excessive recreational screen time, and 32% had inadequate sleep. The final dataset will be analysed for the conference. Conclusions Many Australian adolescents are engaging in lifestyle behaviours that put them at risk of chronic disease. Effective and scalable preventive interventions that simultaneously target these behaviours are needed. Key messages This is the first trial of an eHealth intervention to concurrently target the Big 6 among adolescents. Health4Life has the potential to improve physical and mental health in adolescence and beyond.