Is early activity resumption after paediatric concussion safe and does it reduce symptom burden at 2 weeks post injury? The Pediatric Concussion Assessment of Rest and Exertion (PedCARE) multicentre randomised clinical trial.

OBJECTIVE: Investigate whether resuming physical activity (PA) at 72 hours post concussion is safe and reduces symptoms at 2 weeks, compared with resting until asymptomatic. METHODS: Real-life conditions, multicentre, single-blinded randomised clinical trial, conducted in three Canadian paediatric emergency departments (ED). Children/youth aged 10-<18 years with acute concussion were recruited between March 2017 and December 2019, and randomly assigned to a 4-week stepwise return-to-PA protocol at 72 hours post concussion even if symptomatic (experimental group (EG)) or to a return-to-PA once asymptomatic protocol (control group (CG)). The primary outcome was self-reported symptoms at 2 weeks using the Health and Behaviour Inventory. Adherence was measured using accelerometers worn 24 hours/day for 14 days post injury. Adverse events (AE) (worsening of symptoms requiring unscheduled ED or primary care visit) were monitored. Multivariable intention-to-treat (ITT) and per-protocol analyses adjusting for prognostically important covariates were examined. Missing data were imputed for the ITT analysis. RESULTS: 456 randomised participants (EG: N=227; mean (SD) age=13.3 (2.1) years; 44.5% women; CG: N=229; mean (SD) age=13.3 (2.2) years; 43.7% women) were analysed. No AE were identified. ITT analysis showed no strong evidence of a group difference at 2 weeks (adjusted mean difference=-1.3 (95% CI:-3.6 to 1.1)). In adherent participants, initiating PA 72 hours post injury significantly reduced symptoms 2 weeks post injury, compared with rest (adjusted mean difference=-4.3 (95% CI:-8.4 to -0.2)). CONCLUSION: Symptoms at 2 weeks did not differ significantly between children/youth randomised to initiate PA 72 hours post injury versus resting until asymptomatic; however, many were non-adherent to the intervention. Among adherent participants, early PA was associated with reduced symptoms at 2 weeks. Resumption of PA is safe and may be associated with milder symptoms at 2 weeks. LEVEL OF EVIDENCE: 1b. TRIAL REGISTRATION NUMBER: NCT02893969. REGISTRY NAME: Pediatric Concussion Assessment of Rest and Exertion (PedCARE).

Variations in hemoglobin measurement and eligibility criteria across blood donation services are associated with differing low-hemoglobin deferral rates: a BEST Collaborative study.

BACKGROUND: Determination of blood donor hemoglobin (Hb) levels is a pre-requisite to ensure donor safety and blood product quality. We aimed to identify Hb measurement practices across blood donation services and to what extent differences associate with low-Hb deferral rates. METHODS: An online survey was performed among Biomedical Excellence for Safer Transfusion (BEST) Collaborative members, extended with published data. Multivariable negative-binomial regression models were built to estimate adjusted associations of minimum donation intervals, Hb cut-offs (high, ≥13.5 g/dL in men or ≥ 12.5 g/dL in women, vs. lower values), iron monitoring (yes/no), providing or prescribing iron supplementation (yes/no), post-versus pre-donation Hb measurement and geographical location (Asian vs. rest), with low-Hb deferral rates. RESULTS: Data were included from 38 blood services. Low-Hb deferral rates varied from 0.11% to 8.81% among men and 0.84% to 31.85% among women. Services with longer minimum donation intervals had significantly lower deferral rates among both women (rate ratio, RR 0.53, 95%CI 0.33-0.84) and men (RR 0.53, 95%CI 0.31-0.90). In women, iron supplementation was associated with lower Hb deferral rates (RR 0.47, 95%CI 0.23-0.94). Finally, being located in Asia was associated with higher low-Hb deferral rates; RR 9.10 (95%CI 3.89-21.27) for women and 6.76 (95%CI 2.45-18.68) for men. CONCLUSION: Differences in Hb measurement and eligibility criteria, particularly longer donation intervals and iron supplementation in women, are associated with variations in low-Hb deferral rates. These insights could help improve both blood donation service efficiency and donor care.

Multicentre, randomised clinical trial of paediatric concussion assessment of rest and exertion (PedCARE): a study to determine when to resume physical activities following concussion in children.

INTRODUCTION: Rest until symptom-free, followed by a progressive stepwise return to activities, is often prescribed in the management of paediatric concussions. Recent evidence suggests prolonged rest may hinder recovery, and early resumption of physical activity may be associated with more rapid recovery postconcussion. The primary objective is to determine whether the early reintroduction of non-contact physical activity beginning 72 hours postinjury reduces postconcussive symptoms at 2 weeks in children following an acute concussion as compared with a rest until asymptomatic protocol. METHODS AND ANALYSIS: This study is a randomised clinical trial across three Canadian academic paediatric emergency departments. A total of 350 participants, aged 10-17.99 years, who present within 48 hours of an acute concussion, will be recruited and randomly assigned to either the study intervention protocol (resumption of physical activity 72 hours postconcussion even if experiencing symptoms) or physical rest until fully asymptomatic. Participants will document their daily physical and cognitive activities. Follow-up questionnaires will be completed at 1, 2 and 4 weeks postinjury. Compliance with the intervention will be measured using an accelerometer (24 hours/day for 14 days). Symptoms will be measured using the validated Health and Behaviour Inventory. A linear multivariable model, adjusting for site and prognostically important covariates, will be tested to determine differences between groups. The proposed protocol adheres to the RCT-CONSORT guidelines. DISCUSSION: This trial will determine if early resumption of non-contact physical activity following concussion reduces the burden of concussion and will provide healthcare professionals with the evidence by which to recommend the best timing of reintroducing physical activities. TRIAL REGISTRATION NUMBER: Trial identifier (Clinicaltrials.gov) NCT02893969.

Relationships Between Outdoor Time, Physical Activity, Sedentary Time, and Body Mass Index in Children: A 12-Country Study.

PURPOSE: This study investigated the relationship between outdoor time and physical activity (PA), sedentary time (SED), and body mass index z scores among children from 12 lower-middle-income, upper-middle-income, and high-income countries. METHODS: In total, 6478 children (54.4% girls) aged 9-11 years participated. Outdoor time was self-reported, PA and SED were assessed with ActiGraph GT3X+ accelerometers, and height and weight were measured. Data on parental education, neighborhood collective efficacy, and accessibility to neighborhood recreation facilities were collected from parent questionnaires. Country latitude and climate statistics were collected through national weather data sources. Gender-stratified multilevel models with parental education, climate, and neighborhood variables as covariates were used to examine the relationship between outdoor time, accelerometry measures, and body mass index z scores. RESULTS: Each additional hour per day spent outdoors was associated with higher moderate- to vigorous-intensity PA (boys: +2.8 min/d; girls: +1.4 min/d), higher light-intensity PA (boys: +2.0 min/d; girls: +2.3 min/d), and lower SED (boys: -6.3 min/d; girls: -5.1 min/d). Effect sizes were generally weaker in lower-middle-income countries. Outdoor time was not associated with body mass index z scores. CONCLUSIONS: Outdoor time was associated with higher PA and lower SED independent of climate, parental education, and neighborhood variables, but effect sizes were small. However, more research is needed in low- and middle-income countries.

A cross-sectional study exploring the relationship between age, gender, and physical measures with adequacy in and predilection for physical activity.

BACKGROUND: Physical literacy is a complex construct influenced by a range of physical, behavioural, affective, and cognitive factors. Researchers are interested in relationships among these constituent factors. The purpose of this study was to investigate how age, gender, and physical competence components of physical literacy relate to a child's adequacy in and predilection for physical activity. METHODS: A sample of 8530 Canadian youth (50% girl) aged 8.0 to 12.9 years participated in the study. Participants completed the Canadian Assessment of Physical Literacy (CAPL) protocol, which assesses physical literacy in four domains: Physical Competence, Daily Behaviour, Motivation and Confidence, and Knowledge and Understanding. Stepwise multiple regression analyses were conducted to investigate the relationship between physical competence components of physical literacy (Progressive Aerobic Cardiovascular Endurance Run [PACER], Canadian Agility and Movement Skill Assessment [CAMSA], sit and reach, handgrip, plank, and body mass index) and children's perceived adequacy and predilection toward physical activity as measured by subscales from the Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity scale (CSAPPA). RESULTS: The variable most strongly associated with adequacy and predilection was the PACER shuttle run score. The PACER accounted for 10.9% of the variance in adequacy and 9.9% of the variance in predilection. Participants' age was inversely related to adequacy (ß = - 0.374) and predilection (ß = - 0.621). The combination of other variables related to adequacy brought the total variance explained to 14.7%, while the model for predilection explained a total of 13.7%. CONCLUSIONS: Results indicate an association between cardiorespiratory fitness and measures of physical activity adequacy and predilection. These findings suggest that practitioners should consider the physiological and psychological makeup of the child, and ways to enhance adequacy and predilection among children with limited cardiorespiratory fitness, in order to create the best possible environment for all children to participate in physical activity.

Refining the Canadian Assessment of Physical Literacy based on theory and factor analyses.

BACKGROUND: The Canadian Assessment of Physical Literacy (CAPL) is a 25-indicator assessment tool comprising four domains of physical literacy: (1) Physical Competence, (2) Daily Behaviour, (3) Motivation and Confidence, and (4) Knowledge and Understanding. The purpose of this study was to re-examine the factor structure of CAPL scores and the relative weight of each domain for an overall physical literacy factor. Our goal was to maximize content representation, and reduce construct irrelevant variance and participant burden, to inform the development of CAPL-2 (a revised, shorter, and theoretically stronger version of CAPL). METHODS: Canadian children (n = 10,034; Mage = 10.6, SD = 1.2; 50.1% girls) completed CAPL testing at one time point. Confirmatory factor analysis was used. RESULTS: Based on weak factor loadings (λs < 0.32) and conceptual alignment, we removed body mass index, waist circumference, sit-and-reach flexibility, and grip strength as indicators of Physical Competence. Based on the factor loading (λ < 0.35) and conceptual alignment, we removed screen time as an indicator of Daily Behaviour. To reduce redundancy, we removed children's activity compared to other children as an indicator of Motivation and Confidence. Based on low factor loadings (λs < 0.35) and conceptual alignment, we removed knowledge of screen time guidelines, what it means to be healthy, how to improve fitness, activity preferences, and physical activity safety gear indicators from the Knowledge and Understanding domain. The final refined CAPL model was comprised of 14 indicators, and the four-factor correlated model fit the data well (r ranged from 0.08 to 0.76), albeit with an unexpected cross-loading from Daily Behaviour to knowledge of physical activity guidelines (mean- and variance-adjusted weighted least square [WLSMV] χ2(70) = 1221.29, p < 0.001, Comparative Fit Index [CFI] = 0.947, root mean square error of approximation [RMSEA] = 0.041[0.039, 0.043]). Finally, our higher-order model with Physical Literacy as a factor with indicators of Physical Competence (λ = 0.68), Daily Behaviour (λ = 0.91), Motivation and Confidence (λ = 0.80), and Knowledge and Understanding (λ = 0.21) fit the data well. CONCLUSIONS: The scores from the revised and much shorter 14-indicator model of CAPL can be used to assess the four correlated domains of physical literacy and/or a higher-order aggregate physical literacy factor. The results of this investigation will inform the development of CAPL-2.

Canadian Assessment of Physical Literacy Second Edition: a streamlined assessment of the capacity for physical activity among children 8 to 12 years of age.

BACKGROUND: The Canadian Assessment of Physical Literacy (CAPL) assesses the capacity of children to lead a physically active lifestyle. It is comprised of a battery of standardized assessment protocols that reflect the Canadian consensus definition of physical literacy. The Royal Bank of Canada Learn to Play - Canadian Assessment of Physical Literacy study implemented the CAPL with 10,034 Canadian children (50.1% female), 8 to 12 years of age. Feedback during data collection, necessary changes identified by the coordinating centre, and recent data analyses suggested that a streamlined, second edition of the CAPL was required. The purpose of this paper is to describe the methods used to develop the CAPL second edition (CAPL-2). METHODS: The larger dataset created through the RBC-Learn to Play CAPL study enabled the re-examination of the CAPL model through factor analyses specific to Canadian children 8 to 12 years of age from across Canada. This comprehensive database was also used to examine the CAPL protocols for redundancy or variables that did not contribute significantly to the overall assessment. Removing redundancy had been identified as a priority in order to reduce the high examiner and participant burden. The "lessons learned" from such a large national surveillance project were reviewed for additional information regarding the changes that would be required to optimize the assessment of children's physical literacy. In addition, administrative changes, improvements, and corrections were identified as necessary to improve the quality and accuracy of the CAPL manual and training materials. RESULTS: For each domain of the CAPL, recommended changes based on the factor analyses, qualitative feedback and theoretical considerations significantly reduced the number of protocols. Specific protocol combinations were then evaluated for model fit within the overarching concept of physical literacy. The CAPL-2 continues to reflect the four components of the Canadian consensus definition of physical literacy: Motivation and Confidence, Physical Competence, Knowledge and Understanding, and engagement in Physical Activity Behaviour. The CAPL-2 is comprised of three Physical Competence protocols (plank, Progressive Aerobic Cardiovascular Endurance Run [PACER], Canadian Agility and Movement Skill Assessment [CAMSA]), two Daily Behaviour protocol (pedometer steps, self-reported physical activity), and a 22-item questionnaire assessing the physical literacy domains of Motivation and Confidence, and Knowledge and Understanding. Detailed information about the CAPL-2 is available online ( www.capl-eclp.ca ). CONCLUSIONS: The CAPL-2 dramatically reduces examiner and participant burden (three Physical Competence protocols, two Daily Behaviour protocols, and a 22-response questionnaire; versus eight Physical Competence protocols, three Daily Behaviour protocols and a 72-response questionnaire for the original CAPL), while continuing to be a comprehensive assessment of all aspects of children's physical literacy using the Canadian consensus definition of this term. Like the original, the CAPL-2 continues to offer maximum flexibility to practitioners, who can choose to complete the entire CAPL-2 assessment, only one or more domains, or select individual protocols. Regardless of the assessment selected, scores are available to interpret the performance of each child relative to Canadian children of the same age and sex. All of the protocols included in the CAPL-2 have published reports of validity and reliability for this age group (8 to 12 years). The detailed manual for CAPL-2 administration, along with training materials and other resources, are available free of charge on the CAPL-2 website ( www.capl-eclp.ca ). All CAPL-2 materials and resources, including the website, are available in both English and French.

Associations between teacher training and measures of physical literacy among Canadian 8- to 12-year-old students.

BACKGROUND: Quality physical education (PE) contributes to the development of physical literacy among children, yet little is known about how teacher training relates to this development. We assessed the association between teacher training, and the likelihood that children met recommended achievement levels for components of physical literacy as defined by the Canadian Assessment of Physical Literacy (CAPL). METHODS: Canadian children (n = 4189; M = 10.72 years, SD = 1.19) from six provinces completed the CAPL. Logistic regression was used to examine the relationship between teacher training (generalist/PE specialist), adjusting for children's age and gender, and physical competence protocols (sit and reach, handgrip, plank, Progressive Aerobic Cardiovascular Endurance Run [PACER], body mass index [BMI], waist circumference, Canadian Agility and Movement Skill Assessment [CAMSA]), the four CAPL domain scores, and the total CAPL score. RESULTS: Teacher training, in addition to children's age and gender, explained only a very small proportion of variance in each model (all R2 < 0.03). Children taught by a generalist were less likely to reach recommended levels of motivation and confidence (OR = 0.83, 95% CI, 0.72-0.95) or CAMSA scores (OR = 0.77, 95% CI, 0.67-0.90), even when accounting for a significant increase in CAMSA score with age (OR = 1.18, 95% CI, 1.12-1.26). All other associations between measures of components of physical literacy and teacher training were not significant. CONCLUSIONS: While teacher training is hypothesized to contribute to the development of physical literacy among elementary school students, the observed effects in this study were either small or null. Children taught by PE specialists were more likely than those taught by generalists to demonstrate recommended levels of motivation and confidence, and to have better movement skills, which are hypothesized to be critical prerequisites for the development of a healthy lifestyle. Further research with more robust designs is merited to understand the impact of teachers' training on the various components of physical literacy development.

Cardiorespiratory fitness is associated with physical literacy in a large sample of Canadian children aged 8 to 12 years.

BACKGROUND: The associations between cardiorespiratory fitness (CRF) and physical literacy in children are largely unknown. The aim of this study was to assess the relationships between CRF, measured using the 20-m shuttle run test (20mSRT), and components of physical literacy among Canadian children aged 8-12 years. METHODS: A total of 9393 (49.9% girls) children, with a mean (SD) age of 10.1 (±1.2) years, from a cross-sectional surveillance study were included for this analysis. The SRT was evaluated using a standardized 15 m or 20 m protocol. All 15 m SRTs were converted to 20mSRT values using a standardized formula. The four domains of physical literacy (Physical Competence, Daily Behaviour, Motivation and Confidence, and Knowledge and Understanding) were measured using the Canadian Assessment of Physical Literacy. Tertiles were identified for 20mSRT laps, representing low, medium, and high CRF for each age and gender group. Cohen's d was used to calculate the effect size between the low and high CRF groups. RESULTS: CRF was strongly and favourably associated with all components of physical literacy among school-aged Canadian children. The effect size between low and high CRF tertile groups was large for the Physical Competence domain (Cohen's d range: 1.11-1.94) across age and gender groups, followed by moderate to large effect sizes for Motivation and Confidence (Cohen's d range: 0.54-1.18), small to moderate effect sizes for Daily Behaviour (Cohen's d range: 0.25-0.81), and marginal to moderate effect sizes for Knowledge and Understanding (Cohen's d range: 0.08-0.70). CONCLUSIONS: This study identified strong favourable associations between CRF and physical literacy and its constituent components in children aged 8-12 years. Future research should investigate the sensitivity and specificity of the 20mSRT in screening those with low physical literacy levels.

Physical literacy levels of Canadian children aged 8-12 years: descriptive and normative results from the RBC Learn to Play-CAPL project.

BACKGROUND: The current physical literacy level of Canadian children is unknown. The Royal Bank of Canada (RBC) Learn to Play - Canadian Assessment of Physical Literacy (CAPL) project, which is anchored in the Canadian consensus statement definition of physical literacy, aimed to help establish the current physical literacy level of Canadian children. METHODS: The CAPL was used to assess the physical literacy (and component domains: Daily Behaviour, Physical Competence, Knowledge and Understanding, and Motivation and Confidence) of Canadian children aged 8-12 years. Data were collected from 11 sites across Canada, yielding a sample of 10,034 participants (5030 girls). Descriptive statistics by age and gender were calculated and percentile distributions of physical literacy scores, including each domain and individual measure, were derived. RESULTS: The mean age of participants was 10.1 ± 1.2 years. Total physical literacy scores (out of 100) were on average 63.1 ± 13.0 for boys and 62.2 ± 11.3 for girls. For boys and girls respectively, domain scores were 19.9 ± 4.7 and 19.3 ± 4.1 (out of 32) for Physical Competence; 18.6 ± 7.9 and 18.5 ± 7.4 (out of 32) for Daily Behaviour; 12.7 ± 2.8 and 12.2 ± 2.6 (out of 18) for Motivation and Confidence; and 11.8 ± 2.8 and 12.2 ± 2.6 (out of 18) for Knowledge and Understanding. Physical Competence measures were on average 28.1 ± 8.4 cm (sit-and-reach flexibility), 33.5 ± 9.4 kg (grip strength, right + left), 23.4 ± 14.1 laps (Progressive Aerobic Cardiovascular Endurance Run [PACER] shuttle run), 61.8 ± 43.8 s (isometric plank), 19.0 ± 3.8 kg/m2 (body mass index), 67.3 ± 10.8 cm (waist circumference), and 20.6 ± 3.9 out of 28 points for the Canadian Agility and Movement Skill Assessment (CAMSA), with scores for boys higher than girls and older children higher than younger children for grip strength, PACER, plank, and CAMSA score. Girls and younger children had better scores on the sit-and-reach flexibility than boys and older children. Daily pedometer step counts were higher in boys than girls (12,355 ± 4252 vs. 10,779 ± 3624), and decreased with age. CONCLUSIONS: These results provide the largest and most comprehensive assessment of physical literacy of Canadian children to date, providing a "state of the nation" baseline, and can be used to monitor changes and inform intervention strategies going forward.

The relationship between sedentary behaviour and physical literacy in Canadian children: a cross-sectional analysis from the RBC-CAPL Learn to Play study.

BACKGROUND: Physical literacy is the foundation of a physically active lifestyle. Sedentary behaviour displays deleterious associations with important health indicators in children. However, the association between sedentary behaviour and physical literacy is unknown. The purpose of this study was to identify the aspects of physical literacy that are associated with key modes of sedentary behaviour among Canadian children participating in the RBC-CAPL Learn to Play study. METHODS: A total of 8,307 children aged 8.0-12.9 years were included in the present analysis. Physical literacy was assessed using the Canadian Assessment of Physical Literacy, which measures four domains (Physical Competence, Daily Behaviour, Motivation and Confidence, Knowledge and Understanding). Screen-based sedentary behaviours (TV viewing, computer and video game use), non-screen sedentary behaviours (reading, doing homework, sitting and talking to friends, drawing, etc.) and total sedentary behaviour were assessed via self-report questionnaire. Linear regression models were used to determine significant (p<0.05) correlates of each mode of sedentary behaviour. RESULTS: In comparison to girls, boys reported more screen time (2.7±2.0 vs 2.2±1.8 hours/day, Cohen's d=0.29), and total sedentary behaviour (4.3±2.6 vs 3.9±2.4 hours/day, Cohen's d=0.19), but lower non-screen-based sedentary behaviour (1.6±1.3 vs 1.7±1.3 hours/day, Cohen's d=0.08) (all p< 0.05). Physical Competence (standardized ß's: -0.100 to -0.036, all p<0.05) and Motivation and Confidence (standardized ß's: -0.274 to -0.083, all p<0.05) were negatively associated with all modes of sedentary behaviour in fully adjusted models. Knowledge and Understanding was negatively associated with screen-based modes of sedentary behaviour (standardized ß's: -0.039 to -0.032, all p<0.05), and positively associated with non-screen sedentary behaviour (standardized ß: 0.098, p<0.05). Progressive Aerobic Cardiovascular Endurance Run score and log-transformed plank score were negatively associated with all screen-based modes of sedentary behaviour, while the Canadian Agility and Movement Skill Assessment score was negatively associated with all modes of sedentary behaviour other than TV viewing (all p<0.05). CONCLUSIONS: These results highlight differences in the ways that screen and non-screen sedentary behaviours relate to physical literacy. Public health interventions should continue to target screen-based sedentary behaviours, given their potentially harmful associations with important aspects of physical literacy.

The relationship between physical literacy scores and adherence to Canadian physical activity and sedentary behaviour guidelines.

BACKGROUND: Physical literacy is an emerging construct in children's health promotion, and may impact their lifelong physical activity habits. However, recent data reveal that only a small portion of Canadian children are regularly physically active and/or meet sedentary behaviour guidelines. To our knowledge, no study has investigated the association between physical literacy and movement behaviour guidelines. Therefore, the purpose of this study was to examine the relationship between physical literacy scores in Canadian children who meet or do not meet physical activity and sedentary behaviour guidelines. METHODS: Children (n = 2956; 56.6% girls) aged 8-12 years from 10 Canadian cities had their physical literacy levels measured using the Canadian Assessment of Physical Literacy, which consists of four domains (Physical Competence; Daily Behaviour; Knowledge and Understanding; and Motivation and Confidence) that are aggregated to provide a composite physical literacy score. Physical activity levels were measured by pedometers, and sedentary behaviour was assessed through self-report questionnaire. Analyses were conducted separately for each guideline, comparing participants meeting versus those not meeting the guidelines. Comparisons were performed using MANOVA and logistic regression to control for age, gender, and seasonality. RESULTS: Participants meeting physical activity guidelines or sedentary behaviour guidelines had higher physical literacy domain scores for Physical Competence and for Motivation and Confidence compared to those not meeting either guideline (both p < 0.0001). Participants had increased odds of meeting physical activity guidelines and sedentary behaviour guidelines if they met the minimum recommended level of the Physical Competence and Motivation and Confidence domains. Significant age (OR 0.9; 95% CI: 0.8, 0.9), gender (OR 0.4; 95% CI: 0.3, 0.5) and seasonality effects (OR 1.6; 95% CI: 1.2, 2.2 spring and OR 1.7; 95% CI: 1.2, 2.5 summer, reference winter) were seen for physical activity guidelines, and age (OR 0.8; 95% CI: 0.7, 0.8) and gender effects (OR 1.7; 95% CI: 1.4, 2.0) for sedentary behaviour guidelines. Knowledge and Understanding of physical activity principles was not related to guideline adherence in either model. CONCLUSIONS: These cross-sectional findings demonstrate important associations between physical literacy and guideline adherence for physical activity and sedentary behaviour. Future research should explore the causality of these associations.

Influence of the relative age effect on children's scores obtained from the Canadian assessment of physical literacy.

BACKGROUND: Age grouping by the imposition of a cut-off date, common in sports and education, promotes a relative age difference that is associated with developmental advantages for children who are born on the "early side" of the cut-off date and disadvantages to those born later in the same year, which is known as the relative age effect (RAE) bias. Acquiring an adequate level of physical literacy is important for children to remain active for life. The Canadian Assessment of Physical Literacy (CAPL) is an assessment protocol that encompasses measures in the domains of children's Daily Behaviours, Physical Competence, Motivation and Confidence, and Knowledge and Understanding. The purpose of this study was to ascertain whether the CAPL scores were susceptible to the RAE, which could affect our interpretation of the CAPL findings. METHODS: This cross-sectional study examined if scores obtained in the CAPL (i.e., the four domains individually and the total CAPL score) were susceptible to the RAE in children aged 8 to 12 years and, if so, which physical competence assessments (movement skills, cardiorespiratory, strength, muscular endurance, flexibility, and body composition measurements) were more susceptible. Participants (n = 8233, 49.8% boys) from the Royal Bank of Canada-CAPL Learn to Play project from 11 sites in seven Canadian provinces were tested using the CAPL protocol. RESULTS: Among boys and girls, the RAE was significantly associated with two and three of the four domain scores, respectively, after controlling for covariates. However, effect sizes were negligible for the comparisons between quarters of the year and physical literacy domains and overall scores. For the main effect of the relative age, boys and girls born in the first three months of the year were taller (F(3, 4074) = 57.0, p < 0.001, ƒ2 = 0.04 and F(3, 4107) = 58.4, p < 0.001, ƒ2 = 0.04, respectively) and demonstrated greater muscular strength (F(3, 4037) = 29.2, p < 0.001, ƒ2 = 0.02 and F(3, 4077) = 25.1, p < 0.001, ƒ2 = 0.02, respectively) compared with those born later in the same year. CONCLUSIONS: Collectively, our results suggest that the RAE bias is mainly negligible with regard to the domain scores and overall CAPL scores in this large sample of children.

Revising the motivation and confidence domain of the Canadian assessment of physical literacy.

BACKGROUND: The Motivation and Confidence domain questionnaire in the Canadian Assessment of Physical Literacy (CAPL) was lengthy (36 single items that aggregate to five subscales), and thus burdensome to both participants and practitioners. The purpose of this study was to use factor analysis to refine the Motivation and Confidence domain to be used in the CAPL-Second Edition (CAPL-2). METHODS: Children, primarily recruited through free-of-charge summer day camps (n = 205, Mage = 9.50 years, SD = 1.14, 50.7% girls), completed the CAPL-2 protocol, and two survey versions of the Motivation and Confidence questionnaire. Survey 1 contained the Motivation and Confidence questionnaire items from the original CAPL, whereas Survey 2 contained a battery of items informed by self-determination theory to assess motivation and confidence. First, factor analyses were performed on individual questionnaires to examine validity evidence (i.e., internal structure) and score reliability (i.e., coefficient H and omega total). Second, factor analyses were performed on different combinations of questionnaires to establish the least burdensome yet well-fitted and theoretically aligned model. RESULTS: The assessment of adequacy and predilection, based on 16 single items as originally conceptualized within the CAPL, was not a good fit to the data. Therefore, a revised and shorter version of these scales was proposed, based on exploratory factor analysis. The self-determination theory items provided a good fit to the data; however, identified, introjected, and external regulation had low score reliability. Overall, a model comprising three single items for each of the following subscales was proposed for use within the CAPL-2: adequacy, predilection, intrinsic motivation, and perceived competence satisfaction. This revised domain fit well within the overall CAPL-2 model specifying a higher-order physical literacy factor (MLRχ2(63) = 81.45, p = 0.06, CFI = 0.908, RMSEA = 0.038, 90% CI (0.00, 0.060)). CONCLUSIONS: The revised and much shorter questionnaire of 12 items that aggregate to four subscales within the domain of Motivation and Confidence is recommended for use in the CAPL-2. The revised domain is aligned with the definition of motivation and confidence within physical literacy and has clearer instructions for completion.

Systematic review of the relationship between 20m shuttle run performance and health indicators among children and youth.

OBJECTIVE: This systematic review aimed to summarize research that assessed the associations between 20m shuttle run test (20mSRT) performance and indicators of physiological, psychosocial and cognitive health among school-aged children and youth. DESIGN: Systematic review. METHODS: Five online databases were used to identify peer-reviewed studies published from 1980 to 2016. Studies were included if they matched these criteria: population (children and youth with a mean age of 5-17 years and/or in Grades 1-12), intervention/exposure (performance on the 20mSRT), and outcomes (health indicators: adiposity, cardiometabolic biomarkers, cognition, mental health, psychosocial health, self-esteem and physical self-perception, quality of life and wellbeing, bone health, musculoskeletal fitness, motor skill development, and injuries and/or harm). Narrative syntheses were applied to describe the results. A lack of homogeneity precluded a meta-analysis approach. RESULTS: Overall, 142 studies that determined an association between 20mSRT performance and a health indicator were identified, representing 319,311 children and youth from 32 countries. 20mSRT performance was favourably associated with indicators of adiposity, and some indicators of cardiometabolic, cognitive, and psychosocial health in boys and girls. Fewer studies examined the relationship between 20mSRT performance and measures of quality of life/wellbeing, mental health and motor skill development, and associations were generally inconsistent. The quality of the evidence ranged from very low to moderate across health indicators. CONCLUSION AND IMPLICATIONS: These findings support the use of the 20mSRT as a holistic indicator of population health in children and youth.

International normative 20†m shuttle run values from 1†142†026 children and youth representing 50 countries.

OBJECTIVE: To develop sex-specific and age-specific international norms for the 20 m shuttle run test (20mSRT) in children and youth (aged 9-17 years), and to estimate the prevalence meeting the FITNESSGRAM criterion-referenced standards for healthy cardiorespiratory endurance (CRE). METHODS: A systematic review was undertaken to identify papers explicitly reporting descriptive 20mSRT (with 1 min stages) data on children and youth since 1981. Data were included on apparently healthy (free from known disease/injury) 9-17 years old. Following standardisation to a common metric and for protocol differences, pseudo data were generated using Monte Carlo simulation, with population-weighted sex-specific and age-specific normative centiles generated using the Lambda Mu and Sigma (LMS) method. Sex-related and age-related differences were expressed as per cent and standardised differences in means. The prevalence with healthy CRE was estimated using the sex-specific and age-specific FITNESSGRAM criterion-referenced standards for [Formula: see text]. RESULTS: Norms were displayed as tabulated centiles and as smoothed centile curves for the 20mSRT using 4 common metrics (speed at the last completed stage, completed stages/minutes, laps and relative [Formula: see text]). The final data set included 1 142 026 children and youth from 50 countries, extracted from 177 studies. Boys consistently outperformed girls at each age group (mean difference±95% CI: 0.86±0.28 km/h or 0.79±0.20 standardised units), with the magnitude of age-related increase larger for boys than for girls. A higher proportion of boys (mean±95% CI: 67±14%) had healthy CRE than girls (mean±95% CI: 54±17%), with the prevalence of healthy CRE decreasing systematically with age. CONCLUSIONS: This study provides the most comprehensive and up-to-date set of international sex-specific and age-specific 20mSRT norms for children and youth, which have utility for health and fitness screening, profiling, monitoring and surveillance.

Systematic review of the relationships between sleep duration and health indicators in school-aged children and youth.

The objective of this systematic review was to examine the relationships between objectively and subjectively measured sleep duration and various health indicators in children and youth aged 5-17 years. Online databases were searched in January 2015 with no date or study design limits. Included studies were peer-reviewed and met the a priori-determined population (apparently healthy children and youth aged 5-17 years), intervention/exposure/comparator (various sleep durations), and outcome (adiposity, emotional regulation, cognition/academic achievement, quality of life/well-being, harms/injuries, and cardiometabolic biomarkers) criteria. Because of high levels of heterogeneity across studies, narrative syntheses were employed. A total of 141 articles (110 unique samples), including 592 215 unique participants from 40 different countries, met inclusion criteria. Overall, longer sleep duration was associated with lower adiposity indicators, better emotional regulation, better academic achievement, and better quality of life/well-being. The evidence was mixed and/or limited for the association between sleep duration and cognition, harms/injuries, and cardiometabolic biomarkers. The quality of evidence ranged from very low to high across study designs and health indicators. In conclusion, we confirmed previous investigations showing that shorter sleep duration is associated with adverse physical and mental health outcomes. However, the available evidence relies heavily on cross-sectional studies using self-reported sleep. To better inform contemporary sleep recommendations, there is a need for sleep restriction/extension interventions that examine the changes in different outcome measures against various amounts of objectively measured sleep to have a better sense of dose-response relationships.

At the Mercy of the Gods: Associations Between Weather, Physical Activity, and Sedentary Time in Children.

OBJECTIVES: This study investigated associations between weather conditions, physical activity, and sedentary time in primary school-aged children in Australia and Canada. METHODS: Cross-sectional data on 9-11-year-old children from the Australian (n = 491) and Canadian (n = 524) sites of the International Study of Childhood Obesity, Lifestyle and the Environment were used. Minutes of daily moderate-to-vigorous-physical-activity (MVPA) and sedentary time were determined from 7-day, 24-h accelerometry (Actigraph GT3X+ triaxial accelerometer). Day-matched weather data (temperature, rainfall, snowfall, relative humidity, wind speed) were obtained from the closest weather station to participants' schools. Covariates included parental highest education level, day type, sex, and BMI z-scores. Generalized mixed model analyses allowing for clustering of participants within schools were completed. Scatterplots with Loess curves were created for maximum temperature, MVPA, and sedentary time. RESULTS: Daily maximum temperature was significantly associated with MVPA and sedentary time in Australia (MVPA p = .05, sedentary p = .01) and Canada (p < .001, p = .001). Rainfall was negatively associated with MVPA in Australia (p < .001) and positively associated with sedentary time in Canada (p = .02). CONCLUSIONS: MVPA and sedentary time appear to be optimal when the maximum temperature ranges between 20°C and 25°C in both countries. The findings have implications for study design and interpretation for surveillance and intervention studies.

Do obese children perceive submaximal and maximal exertion differently?

We examined how obese children perceive a maximal cardiorespiratory fitness test compared with a submaximal cardiorespiratory fitness test. Twenty-one obese children (body mass index ≥95th percentile, ages 10-17 years) completed maximal and submaximal cardiorespiratory fitness tests on 2 separate occasions. Oxygen consumption (VO2) and overall perceived exertion (Borg 15-category scale) were measured in both fitness tests. At comparable workloads, perceived exertion was rated significantly higher (P < 0.001) in the submaximal cardiorespiratory fitness test compared with the maximal cardiorespiratory fitness test. The submaximal cardiorespiratory fitness test was significantly longer than the maximal test (14:21 ± 04:04 seconds vs. 12:48 ± 03:27 seconds, P < 0.001). Our data indicate that at the same relative intensity, obese children report comparable or even higher perceived exertion during submaximal fitness testing than during maximal fitness testing. Perceived exertion in a sample of children and youth with obesity may be influenced by test duration and protocol design.