A collaborative approach to adopting/adapting guidelines. The Australian 24-hour movement guidelines for children (5-12 years) and young people (13-17 years): An integration of physical activity, sedentary behaviour, and sleep.

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.

The feasibility of fundamental movement skill assessments for pre-school aged children.

Fundamental movement skill (FMS) assessment in preschools allows for early intervention; however it is unclear what assessments are feasible. The purpose of this review is to systematically review the feasibility of FMS assessments for pre-school aged children. The search was conducted across four databases, MEDLINE, Scopus, ERIC and SportsDiscus. Search terms included synonyms of "fundamental movement skills" and "pre-school children". Inclusion criteria were: (i) FMS assessment; (ii) feasibility data; (iii) assessment of children aged three to six years; (iv) assessment of typically developing children; and (v) peer reviewed full text publications in English. Feasibility concepts (administration time, equipment, space, assessment type, item, training, qualification) were each coded as 'poor = 1', 'average = 2' and 'good = 3'; potential total of 21. A total of 330 full text articles were considered but a quarter (n = 86) were excluded due to no feasibility data. Sixty-five studies using 13 different FMS assessments were included. The Athletic Skills Track and DEMOST-PRE assessments were most feasible (18/21) and the Test of Gross Motor Development and Movement Assessment Battery for Children were common but among the least feasible (12-14/21). This review allows pre-school staff to choose a FMS assessment based on feasibility. Future studies need to present feasibility of assessments.

Validity and feasibility of an obstacle course to assess fundamental movement skills in a pre-school setting.

Failure to master age-appropriate fundamental movement skills (FMS) at a young age can limit motor skill competence affecting health. Assessments often have issues with feasibility and implementation in a field setting. As such, the purpose of this study was to investigate the validity and feasibility of the Athletic Skills Track (AST), in a pre-school setting. For the validation study sixty-five 3-6 year old children (25 boys and 40 girls) from five pre-schools across Adelaide, Australia participated. Correlations and linear regression analysis (adjusted for age and gender) were used to investigate the association between the time to complete the AST and the raw score of the Test of Gross Motor Development 2 (TGMD-2). For the feasibility study pre-school staff completed a semi-structured interview regarding the feasibility of the AST. The AST took less than a minute per child and the TGMD-2 around 20 minutes for two children. There was a strong negative correlation (r = -0.63, p < 0.01) between the AST scores and the TGMD-2 scores. All five staff reported strengths of the AST to be its short administration time, setup and appropriateness. These results suggest that the AST could be a feasible and valid method of FMS assessment in Australian pre-schools.

Relationships between digit ratio (2D:4D) and female competitive rowing performance.

BACKGROUND: Digit ratio (2D:4D), a measure of prenatal testosterone exposure, is weakly-to-moderately associated with increased physical performance, although the evidence is far stronger for males than females. OBJECTIVE: To examine the relationship between 2D:4D and measured on-water rowing performance in young females competing at the Australian Rowing Championships. METHODS: Using an observational, cross-sectional design, female rowers (n = 69, aged 12-30 years) who competed in single sculls events at the Australian Rowing Championships in 2007 and 2008 had numerous physical and digital anthropometric measurements taken, including 2D:4D measurements. Relationships between 2D:4Ds and race times were examined using Pearson's correlations, partial correlations and multiple regression. Partial Least Squares regression analysis determined the strength of the 2D:4D as a predictor of race time relative to 78 body dimensions plus age. RESULTS: Overall, weak to strong positive correlations between 2D:4D and race time were found; that is, females with smaller 2D:4Ds had faster race times than females with larger 2D:4Ds. Relationships were weak to moderate for all females (r = 0.29-0.32), moderate-to-strong for senior rowers (aged ≥20 years; r = 0.42-0.55), and weak for junior rowers (aged <20 years; r = 0.13-0.18), with all relationships persisting following adjustment for age. Partial Least Squares regression analysis showed that 2D:4Ds had high predictive importance relative to other body dimensions. CONCLUSIONS: Females with smaller 2D:4Ds rowed substantially faster than females with larger 2D:4Ds, with the 2D:4D possibly linked to underlying characteristics that have been optimized over time resulting in better rowing performance.

Can resistance training change the strength, body composition and self-concept of overweight and obese adolescent males? A randomised controlled trial.

BACKGROUND/AIM: Resistance training is an exercise modality at which overweight and obese adolescents can excel and which can therefore positively affect their psychological well-being. The aim of this study was to determine the effect of a 6-month resistance training intervention on the self-concept strength and body composition of overweight and obese adolescent males. METHODS: 56 overweight and obese males aged 13-17 years were randomly allocated to an Intervention (n=30) or Control (n=26) group. Primary (psychological) and secondary (strength and body composition) outcomes were assessed at baseline as well as at 3 (halfway through the intervention), 6 (immediately postintervention) and 12 months follow-up. Random effects mixed modelling was used to determine the effects of the intervention. RESULTS: Statistically significant differences between the Intervention and Control groups were observed at 3-month and 6-month assessments for exercise self-efficacy, resistance training confidence and self-esteem. Large increases in strength for the Intervention group, relative to Controls, were also observed with no substantial changes in body composition shown for either group. Values for all variables returned to baseline following completion of the programme. CONCLUSIONS: A 6-month resistance training intervention can positively affect the self-concept and strength of overweight and obese adolescent boys.

Is three-dimensional anthropometric analysis as good as traditional anthropometric analysis in predicting junior rowing performance?

With the use of three-dimensional whole body scanning technology, this study compared the 'traditional' anthropometric model [one-dimensional (1D) measurements] to a 'new' model [1D, two-dimensional (2D), and three-dimensional (3D) measurements] to determine: (1) which model predicted more of the variance in self-reported best 2000-m ergometry rowing performance; and (2) what were the best anthropometric predictors of ergometry performance, for junior rowers competing at the 2007 and 2008 Australian Rowing Championships. Each rower (257 females, 16.3 ± 1.4 years and 243 males, 16.6 ± 1.5 years) completed a performance and demographic questionnaire, had their mass, standing and sitting height physically measured and were landmarked and scanned using the Vitus Smart® 3D whole body scanner. Absolute and proportional anthropometric measurements were extracted from the scan files. Partial least squares regression analysis, with anthropometric measurements and age as predictor variables and self-reported best 2000-m ergometer time as the response variable, was used to first compare the two models and then to determine the best performance predictors. The variance explained by each model was similar for both male [76.1% (new) vs. 73.5% (traditional)] and female [72.3% (new) vs. 68.6% (traditional)] rowers. Overall, absolute rather than proportional measurements, and 2D and 3D rather than 1D measurements, were the best predictors of rowing ergometry performance, with whole body volume and surface area, standing height, mass and leg length the strongest individual predictors.

Player Profiling and Monitoring in Basketball: A Delphi Study of the Most Important Non-Game Performance Indicators from the Perspective of Elite Athlete Coaches.

BACKGROUND: Little is known about which indicators of performance elite athlete coaches (i.e., professional coaches who coach at the national or international levels) consider to be important for basketball. OBJECTIVE: Using a Delphi procedure, the aim of this study was to identify the non-game performance indicators elite athlete coaches consider to be important for the recruitment/selection of basketball players. METHODS: Ninety elite athlete coaches (basketball coaches (n = 71) and strength/conditioning coaches (n = 19) who coached men (n = 60), women (n = 23), or both (n = 7)), employed in 23 countries across six continents, participated in a three-round online Delphi survey. Round 1 asked coaches to identify the non-game performance indicators (i.e., measures other than game statistics) they currently used (or would like to use) for player recruitment/selection, with common indicators combined into single indicators. Round 2 asked coaches to rate the importance of each performance indicator using a Likert scale (range: 0 = no importance whatsoever to 10 = extremely important). Round 3 asked coaches to identify the single best test measure for each indicator rated ≥ 6 (i.e., important to extremely important) in Round 2. Results were reported descriptively. RESULTS: A total of 608 responses (344 after removal of duplicates) were reported in Round 1, which were collapsed into 35 indicators, all of which were rated as 'important' in Round 2. Psychological and game intelligence indicators were typically rated as very important to extremely important (i.e., median = 9), with physical fitness and movement skills typically rated as very important (i.e., median = 8). For most indicators, coach observation was identified as the best test measure, with unique objective performance/anthropometric tests identified for all physical fitness indicators. CONCLUSION: This study identified a range of psychological, game intelligence, physical fitness, and movement skill indicators that were considered by elite athlete coaches to be important to extremely important for the recruitment/selection of basketball players. These findings may inform the development of a basketball-specific test battery for recruiting/selecting and monitoring players.

Validation of the Physical Activity Questions in the World Health Organization Health Behavior in School-Aged Children Survey Using Accelerometer Data in Japanese Children and Adolescents.

BACKGROUND: An international physical activity (PA) questionnaire is beneficial to make cross-country comparisons among children and adolescents. This study assesses the validity of the PA questions in the World Health Organization Health Behavior in School-Aged Children (WHO HBSC) survey in Japanese children and adolescents. METHODS: Participants were fifth- to sixth-grade Japanese primary school students (67 students aged 10.8 [0.5] y) and first- to third-grade junior high school students (108 students aged 13.0 [0.7] y). The Japanese version of the PA questions in the WHO HBSC (WHO HBSC-J) was used. To assess the validity of the PA questions, the authors used a partial correlation adjusted for sex, age, and relative weight between the answers to the survey questions and objectively measured moderate to vigorous PA (MVPA) by an accelerometer. RESULTS: A significant positive correlation was found between accelerometer-measured MVPA and the number of reported days with at least 60 minutes/day of MVPA in primary school students (r = .39, P = .002) and junior high school students (r = .32, P < .001). CONCLUSION: The HBSC-J has moderate validity for evaluating MVPA in Japanese primary school and junior high school students.

Three-dimensional anthropometric analysis: differences between elite Australian rowers and the general population.

The aim of this study was to quantify the anthropometric differences between elite senior Australian rowers and the Australian adult population using three-dimensional (3D) whole-body scanning. The dimensions of senior rowers competing at the 2007-2008 Australian Rowing Championships were compared with those of an age-matched sample of Australian adults. Mass, height, and sitting height were measured before the participants underwent a 3D whole-body scan, with lengths, breadths, girths, cross-sectional and surface areas, and volumes extracted from each scan. Differences in means and variability between the two groups were expressed as standardized effect sizes and ratios of coefficients of variation. Heavyweight rowers were generally much larger than the general population in absolute size, with 3D dimensions and height and mass showing the largest effects. In contrast, lightweight rowers were generally similar or smaller in absolute and proportional size. The dimensions of rowers, especially the lightweights, were also generally less variable than those of the general population. The greatest differences between elite rowers and the general population were seen in dimensions that could not be captured without 3D scanning, such as segmental volumes and cross-sectional areas.

The International Impact of the Active Healthy Kids Global Alliance Physical Activity Report Cards for Children and Youth.

BACKGROUND: In response to growing concerns over high levels of physical inactivity among young people, the Active Healthy Kids Global Alliance developed a series of national Report Cards on physical activity for children and youth to advocate for the promotion of physical activity. This article provides updated evidence of the impact of the Report Cards on powering the movement to get children and youth moving globally. METHODS: This assessment was performed using quantitative and qualitative sources of information, including surveys, peer-reviewed publications, e-mails, gray literature, and other sources. RESULTS: Although it is still too early to observe a positive change in physical activity levels among children and youth, an impact on raising awareness and capacity building in the national and international scientific community, disseminating information to the general population and stakeholders, and on powering the movement to get kids moving has been observed. CONCLUSIONS: It is hoped that the Report Card activities will initiate a measurable shift in the physical activity levels of children and contribute to achieving the 4 strategic objectives of the World Health Organization Global Action Plan as follows: creating an active society, creating active environments, creating active lives, and creating active systems.

Report Card Grades on the Physical Activity of Children and Youth Comparing 30 Very High Human Development Index Countries.

BACKGROUND: To better understand the childhood physical inactivity crisis, Report Cards on physical activity of children and youth were prepared concurrently in 30 very high Human Development Index countries. The aim of this article was to present, describe, and compare the findings from these Report Cards. METHODS: The Report Cards were developed using a harmonized process for data gathering, assessing, and assigning grades to 10 common physical activity indicators. Descriptive statistics were calculated after converting letter grades to interval variables, and correlational analyses between the 10 common indicators were performed using Spearman's rank correlation coefficients. RESULTS: A matrix of 300 grades was obtained with substantial variations within and between countries. Low grades were observed for behavioral indicators, and higher grades were observed for sources of influence indicators, indicating a disconnect between supports and desired behaviors. CONCLUSION: This analysis summarizes the level and context of the physical activity of children and youth among very high Human Development Index countries, and provides additional evidence that the situation regarding physical activity in children and youth is very concerning. Unless a major shift to a more active lifestyle happens soon, a high rate of noncommunicable diseases can be anticipated when this generation of children reaches adulthood.

Global Matrix 3.0 Physical Activity Report Card Grades for Children and Youth: Results and Analysis From 49 Countries.

BACKGROUND: Accumulating sufficient moderate to vigorous physical activity is recognized as a key determinant of physical, physiological, developmental, mental, cognitive, and social health among children and youth (aged 5-17 y). The Global Matrix 3.0 of Report Card grades on physical activity was developed to achieve a better understanding of the global variation in child and youth physical activity and associated supports. METHODS: Work groups from 49 countries followed harmonized procedures to develop their Report Cards by grading 10 common indicators using the best available data. The participating countries were divided into 3 categories using the United Nations' human development index (HDI) classification (low or medium, high, and very high HDI). RESULTS: A total of 490 grades, including 369 letter grades and 121 incomplete grades, were assigned by the 49 work groups. Overall, an average grade of "C-," "D+," and "C-" was obtained for the low and medium HDI countries, high HDI countries, and very high HDI countries, respectively. CONCLUSIONS: The present study provides rich new evidence showing that the situation regarding the physical activity of children and youth is a concern worldwide. Strategic public investments to implement effective interventions to increase physical activity opportunities are needed.

Secular trends in the prevalence of childhood overweight and obesity across Australian states: A meta-analysis.

OBJECTIVE: To describe secular trends in the prevalence of overweight and obesity in Australian children in each state and territory. DESIGN: Systematic search and numerical meta-analysis. METHODS: A systematic search was conducted to identify all sources that objectively measured the height and weight of Australian children (aged 2-18 years) and had a sample size of at least 300. Raw and summary data were requested from authors and divided into age×sex×state×yearly slices to derive estimates of the prevalence of overweight and obesity. Following a double arcsine transformation to facilitate meta-analysis, all estimates were standardised for age, stratified by sex and analysed using sample-weighted non-linear regressions. RESULTS: The systematic search identified 73 eligible sources (47 raw and 26 summary datasets), with 72.8% of data sourced from Victoria and South Australia. Prevalence trends varied from state to state, with three states or territories showing a marked plateau, two showing a decline in the more recent years and three showing continued linear increases. Tasmania and Northern Territory generally had the highest prevalence (30.2% and 24.3% overweight and obesity respectively), and the Australian Capital Territory had the lowest (12.4% overweight and obesity). CONCLUSIONS: Prevalence, as well as prevalence trends, varied amongst Australian states and territories. At a national level, the prevalence trend has nearly plateaued for the past 15 years. However, upward prevalence trends appear to be persisting in Western Australia, South Australia and Tasmania. Findings highlight the need for ongoing efforts to address the issue of childhood obesity.

The ability of UK offshore workers of different body size and shape to egress through a restricted window space.

404 male offshore workers aged 41.4 ± 10.7 y underwent 3D body scanning and an egress task simulating the smallest helicopter window emergency exit size. The 198 who failed were older (P < 0.01), taller (P < 0.05) and heavier (P < 0.0001) than the 206 who passed. Using all extracted dimensions from the scans, binary logistic regression identified a model (refined using backward elimination) which predicted egress outcome with 75.2% accuracy. Using only weight, bideltoid breadth and maximum chest depth, the model achieved ∼70% accuracy. When anatomical dimensions categorise individuals for small window egress, 25% or more will be misclassified, with false positives (those predicted to fail, but pass) slightly outnumbering false negatives (those predicted to pass, but fail), highlighting the limitations of a predictive approach which treats the body as a rigid object. Differences in flexibility and technique may explain these observations, which may be important considerations for future research.

Australia and Other Nations Are Failing to Meet Sedentary Behaviour Guidelines for Children: Implications and a Way Forward.

BACKGROUND: Australia has joined a growing number of nations that have evaluated the physical activity and sedentary behavior status of their children. Australia received a "D minus" in the first Active Healthy Kids Australia Physical Activity Report Card. METHODS: An expert subgroup of the Australian Report Card Research Working Group iteratively reviewed available evidence to answer 3 questions: (a) What are the main sedentary behaviors of children? (b) What are the potential mechanisms for sedentary behavior to impact child health and development? and (c) What are the effects of different types of sedentary behaviors on child health and development? RESULTS: Neither sedentary time nor screen time is a homogeneous activity likely to result in homogenous effects. There are several mechanisms by which various sedentary behaviors may positively or negatively affect cardiometabolic, neuromusculoskeletal, and psychosocial health, though the strength of evidence varies. National surveillance systems and mechanistic, longitudinal, and experimental studies are needed for Australia and other nations to improve their grade. CONCLUSIONS: Despite limitations, available evidence is sufficiently convincing that the total exposure and pattern of exposure to sedentary behaviors are critical to the healthy growth, development, and wellbeing of children. Nations therefore need strategies to address these common behaviors.

The contribution of organised sports to physical activity in Australia: Results and directions from the Active Healthy Kids Australia 2014 Report Card on physical activity for children and young people.

Youth participation in organised sport and physical activity is important for healthy development, growth and wellbeing. In 2014, Active Healthy Kids Australia released its inaugural Report Card on Physical Activity for Children and Young People, which synthesised the best available national- and state-level data for children and young people (<18 years). This paper provides a more detailed examination of the evidence informing the grade for Organised Sport from the 2014 Report Card, compares Australia's Organised Sport grade with other countries, identifies future directions for research and surveillance, and explores possible beneficial strategies. The Report Card highlighted that between 64% and 85% of Australians aged 5-17 years participate in organised sports, a rate higher than alternate forms of physical activity such as active transportation, active play and school based physical activity. This finding reflects Australia's position as one of the global leaders for participating in organised sport. Future research and surveillance methodologies however, need to incorporate standardised metrics that aim to capture more detailed data regarding organised sport participation. Facilitating access for all children and preventing dropout from organised sports are important initiatives to improve current levels of sport participation. However, given that 80% of Australians aged 5-17 years are not sufficiently physically active to achieve the daily recommendation, participation in sport alone is not enough to ensure that children can accrue the health benefits associated with being physically active. As such, there is a pressing need to develop strategies that engage children in other forms of physical activity such as active transportation and active play.

Results From Australia's 2016 Report Card on Physical Activity for Children and Youth.

BACKGROUND: Two years on from the inaugural Active Healthy Kids Australia (AHKA) Physical Activity Report Card, there has been little to no change with the majority of Australian children still insufficiently active. METHODS: The 2016 AHKA Report Card was developed using the best available national- and state-based physical activity data, which were evaluated by the AHKA Research Working Group using predetermined weighting criteria and benchmarks to assign letter grades to the 12 Report Card indicators. RESULTS: In comparison with 2014, Overall Physical Activity Levels was again assigned a D- with Organized Sport and Physical Activity Participation increasing to a B (was B-) and Active Transport declining to a C- (was C). The settings and sources of influence again performed well (A- to a C+), however Government Strategies and Investments saw a decline (C+ to a D). The traits associated with physical activity were also graded poorly (C- to a D). CONCLUSIONS: Australian youth are insufficiently active and engage in high levels of screen-based sedentary behaviors. While a range of support structures exist, Australia lacks an overarching National Physical Activity Plan that would unify the country and encourage the cultural shift needed to face the inactivity crisis head on.

Results from Australia's 2014 Report Card on Physical Activity for Children and Youth.

BACKGROUND: Like many other countries, Australia is facing an inactivity epidemic. The purpose of the Australian 2014 Physical Activity Report Card initiative was to assess the behaviors, settings, and sources of influences and strategies and investments associated with the physical activity levels of Australian children and youth. METHODS: A Research Working Group (RWG) drawn from experts around Australia collaborated to determine key indicators, assess available datasets, and the metrics which should be used to inform grades for each indicator and factors to consider when weighting the data. The RWG then met to evaluate the synthesized data to assign a grade to each indicator. RESULTS: Overall Physical Activity Levels were assigned a grade of D-. Other physical activity behaviors were also graded as less than average (D to D-), while Organized Sport and Physical Activity Participation was assigned a grade of B-. The nation performed better for settings and sources of influence and Government Strategies and Investments (A- to a C). Four incompletes were assigned due to a lack of representative quality data. CONCLUSIONS: Evidence suggests that physical activity levels of Australian children remain very low, despite moderately supportive social, environmental and regulatory environments. There are clear gaps in the research which need to be filled and consistent data collection methods need to be put into place.

What is the effect of resistance training on the strength, body composition and psychosocial status of overweight and obese children and adolescents? A Systematic review and meta-analysis.

BACKGROUND: Overweight and obese children and adolescents face many physical and psychosocial hardships. Resistance training is a modality of exercise which allows this at-risk group to excel and therefore has the potential to positively affect not only their physical but also psychosocial health. OBJECTIVE: To systematically review and meta-analyse the peer-reviewed literature to determine the effect of resistance training on the strength, body composition and psychosocial status of overweight and/or obese children and/or adolescents. DATA SOURCES: Relevant databases (MEDLINE, Embase, Scopus, Web of Science, SPORTDiscus, CINAHL, PsycINFO, Cochrane library, ProQuest) were searched up to and including 30 January 2013. STUDY SELECTION: Included studies (n = 40, from the 2,247 identified) were randomised controlled trials (RCTs), non-randomised controlled trials (NRCTs) and uncontrolled trials (UCTs) which had run an exercise intervention, with a resistance training component, for overweight and/or obese children and/or adolescents, and which had examined the effect of resistance training on either strength, body composition or psychosocial outcomes. STUDY APPRAISAL AND SYNTHESIS METHODS: Studies were initially critically appraised for risk of bias by the lead author, following which both co-authors critically appraised five randomly selected studies to assess reliability. RESULTS: Randomised controlled trials and NRCTs were analysed separately from UCTs. To determine the overall intervention effect for each outcome variable for each study design group, standardised mean differences were calculated with each individual study/data set weighted by the inverse of the pooled variance. The overall intervention effect reported for RCTs and NRCTs was relative to the control group whereas the effect reported for UCTs shows an overall post-intervention effect. Subgroup analyses, which determined whether the overall intervention effect was influenced by intervention type, training volume, age, sex, risk of bias or study design (for RCT/NRCT group only), were run using the same summary measure. Typically, resistance training had very small to small effects on body composition and moderate to large effects on strength in favour of the intervention. However, the magnitude and direction of the effect of resistance training on psychological outcomes are still unclear given the limited number of studies which looked at psychosocial outcomes and the inconclusive results shown by this review. Uncontrolled trials typically showed larger intervention effects than RCTs and NRCTs; however, these results may be greatly influenced by maturational changes rather than the intervention itself. LIMITATIONS: The included studies employed a number of different exercise intervention types (e.g. resistance training, resistance plus aerobic training etc.) that ranged from 6 to 52 weeks in duration. Studies also employed a number of different methodologies to assess similar outcome measures (e.g. dual energy X-ray absorptiometry versus skinfolds to assess body composition; one-repetition maximum testing versus hand grip strength to assess strength). However, by completing subgroup analyses and using a standardised summary measure these limitations have been accounted for. CONCLUSION: While the effect of resistance training on the body composition and strength of overweight and obese children and adolescents is clear, given the paucity of conclusive data more studies are needed to fully understand the effect of resistance training on the psychosocial status of this population.