Kevin Belanger

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.

Later Bedtime is Associated with Greater Daily Energy Intake and Screen Time in Obese Adolescents Independent of Sleep Duration

Objective: To examine if sleep timing (combination of bedtime and wake up time) is associated with energy intake and physical activity/sedentary behaviour in obese adolescents. Methods: Participants included in this cross-sectional examination were 26 (13 females) obese volunteers (BMI ≥ 95th percentile) with a mean age of 13.6 ± 0.5 years and valid data on self-reported sleep, food intake (dietary record), physical activity and sedentary time (accelerometer), screen time (self-reported), and anthropometry (BMI). We categorized participants as “late sleepers” (midpoint of sleep >3:30 a.m., n=13) and participants as “normal sleepers” (midpoint of sleep ≤ 2:30 a.m., n=13). Results: As expected, wake-up time and bedtime were different between sleep timing groups (p<0.01); however, total sleep duration was the same (9.23 ± 1.14 vs. 9.16 ± 1.28 hours for normal and late sleepers, respectively, p=0.88). There was no significant BMI difference between late sleepers and normal sleepers. Total daily caloric intake was 27% higher in late sleepers (425 kcal) compared to normal sleepers (p=0.04). Using a linear regression model in the whole sample we observed that later sleep timing was associated with greater total caloric intake, independent of age, sex, BMI, moderate-to-vigorous physical activity (MVPA) and sleep duration (β=368.6, p=0.01). No association was found between sleep timing and MVPA or sedentary time. However, later sleep timing was related to greater screen time, independent of age, sex, BMI and sleep duration (β=105.7, p<0.01). Conclusion: The present study is the first to report that later bedtime is associated with greater caloric intake and screen time in obese adolescents independent of total sleep duration.

Systematic review of the relationship between 20 m 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.

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

BackgroundThe 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).MethodsCanadian 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.ResultsBased 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.ConclusionsThe 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.

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

BackgroundPhysical 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.MethodsA 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.ResultsIn 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 β’s: -0.100 to -0.036, all p<0.05) and Motivation and Confidence (standardized β’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 β’s: -0.039 to -0.032, all p<0.05), and positively associated with non-screen sedentary behaviour (standardized β: 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).ConclusionsThese 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.

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.