Moderate-to-vigorous physical activity (MVPA) is essential for disease prevention and health promotion. Emerging evidence suggests other intensities of physical activity (PA), including light-intensity activity (LPA), may also be important, but there has been no rigorous evaluation of the evidence. The purpose of this systematic review was to examine the relationships between objectively measured PA (total and all intensities) and health indicators in school-aged children and youth. Online databases were searched for peer-reviewed studies that met the a priori inclusion criteria: population (apparently healthy, aged 5-17 years), intervention/exposure/comparator (volumes, durations, frequencies, intensities, and patterns of objectively measured PA), and outcome (body composition, cardiometabolic biomarkers, physical fitness, behavioural conduct/pro-social behaviour, cognition/academic achievement, quality of life/well-being, harms, bone health, motor skill development, psychological distress, self-esteem). Heterogeneity among studies precluded meta-analyses; narrative synthesis was conducted. A total of 162 studies were included (204 171 participants from 31 countries). Overall, total PA was favourably associated with physical, psychological/social, and cognitive health indicators. Relationships were more consistent and robust for higher (e.g., MVPA) versus lower (e.g., LPA) intensity PA. All patterns of activity (sporadic, bouts, continuous) provided benefit. LPA was favourably associated with cardiometabolic biomarkers; data were scarce for other outcomes. These findings continue to support the importance of at least 60 min/day of MVPA for disease prevention and health promotion in children and youth, but also highlight the potential benefits of LPA and total PA. All intensities of PA should be considered in future work aimed at better elucidating the health benefits of PA in children and youth.Key words: physical activity, body composition, cardiometabolic biomarkers, fitness, behavioural conduct, bone health, academic achievement, quality of life, well-being, children.Résumé : L'activité physique d'intensité moyenne à vigoureuse (« MVPA ») est essentielle à la prévention des maladies et à la promotion de la santé. D'après de récentes données, l'activité physique (« PA ») pratiquée à d'autres intensités telles que légères (« LPA ») s'avère aussi importante, mais il n'y a pas d'évaluation rigoureuse de ces faits. Cette analyse documentaire systématique a pour objectif d'examiner la relation entre l'activité physique mesurée objectivement (totale et à chacune des intensités) et des indicateurs de la santé chez des enfants et des jeunes d'âge scolaire. On a cherché dans des bases de données en ligne pour identifier des études révisées par des pairs et présentant a priori les critères d'inclusion suivants : population (apparemment en santé, sujets âgés de 5 à 17 ans), intervention/exposition/comparateur (volume, durée, fréquence, intensité et types de mesure objective de PA) et le résultat (composition c...

PurposeThe primary aim of this study was to develop an assessment of the fundamental, combined, and complex movement skills required to support childhood physical literacy. The secondary aim was to establish the feasibility, objectivity, and reliability evidence for the assessment.MethodsAn expert advisory group recommended a course format for the assessment that would require children to complete a series of dynamic movement skills. Criterion-referenced skill performance and completion time were the recommended forms of evaluation. Children, 8–12 years of age, self-reported their age and gender and then completed the study assessments while attending local schools or day camps. Face validity was previously established through a Delphi expert (n = 19, 21% female) review process. Convergent validity was evaluated by age and gender associations with assessment performance. Inter- and intra-rater (n = 53, 34% female) objectivity and test–retest (n = 60, 47% female) reliability were assessed through repeated test administration.ResultsMedian total score was 21 of 28 points (range 5–28). Median completion time was 17 s. Total scores were feasible for all 995 children who self-reported age and gender. Total score did not differ between inside and outside environments (95% confidence interval (CI) of difference: −0.7 to 0.6; p = 0.91) or with/without footwear (95%CI of difference: −2.5 to 1.9; p = 0.77). Older age (p < 0.001, η2 = 0.15) and male gender (p < 0.001, η2 = 0.02) were associated with a higher total score. Inter-rater objectivity evidence was excellent (intraclass correlation coefficient (ICC) = 0.99) for completion time and substantial for skill score (ICC = 0.69) for 104 attempts by 53 children (34% female). Intra-rater objectivity was moderate (ICC = 0.52) for skill score and excellent for completion time (ICC = 0.99). Reliability was excellent for completion time over a short (2–4 days; ICC = 0.84) or long (8–14 days; ICC = 0.82) interval. Skill score reliability was moderate (ICC = 0.46) over a short interval, and substantial (ICC = 0.74) over a long interval.ConclusionThe Canadian Agility and Movement Skill Assessment is a feasible measure of selected fundamental, complex and combined movement skills, which are an important building block for childhood physical literacy. Moderate-to-excellent objectivity was demonstrated for children 8–12 years of age. Test–retest reliability has been established over an interval of at least 1 week. The time and skill scores can be accurately estimated by 1 trained examiner.

This project examined the feasibility, validity, and reliability of the plank isometric hold for children 8-12 years of age. 1502 children (52.5% female) performed partial curl-up and/or plank protocols to assess plank feasibility (n = 823, 52.1% girls), validity (n = 641, 54.1% girls) and reliability (n = 111, 47.8% girls). 12% (n = 52/431) of children could not perform a partial curl-up, but virtually all children (n = 1066/1084) could attain a nonzero score for the plank. Plank performance without time limit was influenced by small effects with age (β = 6.86; p < .001, η(2) = 0.03), flexibility (β = 0.79; p < .001, η(2) = 0.03), and medium effects with cardiovascular endurance (β = 1.07; p < .001, η(2) = 0.08), and waist circumference (β = -0.92; p < .001, η(2) = 0.06). Interrater (ICC = 0.62; CI = 0.50, 0.75), intra-rater (ICC = 0.83; CI = 0.73, 0.90) and test-retest (ICC = 0.63; CI = 0.46, 0.75) reliability were acceptable for the plank without time limit. These data suggest the plank without time limit is a feasible, valid and reliable assessment of torso muscular endurance for children 8-12 years of age.

SUMMARYCross-sectional associations between objectively-measured sleep duration, sleep efficiency and sleep timing with adiposity and physical activity were examined in a cohort of 567 children from Ottawa, Canada. Fivehundred and fifteen children (58.8% female; age: 10.0 AE 0.4 years) had valid sleep measurements and were included in the present analyses. Physical activity, sedentary time and sleep parameters were assessed over 7 days (actigraphy). Height, weight and waist circumference were measured according to standardized procedures. Percentage body fat was assessed using bioelectric impedance analysis. Light physical activity and sedentary time were greater in children with the shortest sleep durations (P < 0.0001), whereas children with the highest sleep efficiencies had lower light physical activity and more sedentary time across tertiles (P < 0.0001). In multivariable linear regression analyses, and after adjusting for a number of covariates, sleep efficiency was inversely related to all adiposity indices (P < 0.05). However, sleep duration and sleep timing were not associated with adiposity indices after controlling for covariates. Inverse associations were noted between sleep duration and light physical activity and sedentary time (P < 0.0001). Sleep efficiency (P < 0.0001), wake time and sleep timing midpoint (P < 0.05) were negatively associated with light physical activity, but positively associated with sedentary time. In conclusion, only sleep efficiency was independently correlated with adiposity in this sample of children. Participants with the shortest sleep durations or highest sleep efficiencies had greater sedentary time. More research is needed to develop better sleep recommendations in children that are based on objective measures of sleep duration, sleep efficiency and sleep timing alike.