BackgroundThe prominence of sedentary behavior research in health science has grown rapidly. With this growth there is increasing urgency for clear, common and accepted terminology and definitions. Such standardization is difficult to achieve, especially across multi-disciplinary researchers, practitioners, and industries. The Sedentary Behavior Research Network (SBRN) undertook a Terminology Consensus Project to address this need.MethodFirst, a literature review was completed to identify key terms in sedentary behavior research. These key terms were then reviewed and modified by a Steering Committee formed by SBRN. Next, SBRN members were invited to contribute to this project and interested participants reviewed and provided feedback on the proposed list of terms and draft definitions through an online survey. Finally, a conceptual model and consensus definitions (including caveats and examples for all age groups and functional abilities) were finalized based on the feedback received from the 87 SBRN member participants who responded to the original invitation and survey.ResultsConsensus definitions for the terms physical inactivity, stationary behavior, sedentary behavior, standing, screen time, non-screen-based sedentary time, sitting, reclining, lying, sedentary behavior pattern, as well as how the terms bouts, breaks, and interruptions should be used in this context are provided.ConclusionIt is hoped that the definitions resulting from this comprehensive, transparent, and broad-based participatory process will result in standardized terminology that is widely supported and adopted, thereby advancing future research, interventions, policies, and practices related to sedentary behaviors.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-017-0525-8) contains supplementary material, which is available to authorized users.

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.

BackgroundThe Canadian Society for Exercise Physiology convened representatives of national organizations, research experts, methodologists, stakeholders, and end-users who followed rigorous and transparent guideline development procedures to create the Canadian 24-Hour Movement Guidelines for the Early Years (0–4 years): An Integration of Physical Activity, Sedentary Behaviour, and Sleep. These novel guidelines for children of the early years embrace the natural and intuitive integration of movement behaviours across the whole day (24-h period).MethodsThe development process was guided by the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument. Four systematic reviews (physical activity, sedentary behaviour, sleep, combined behaviours) examining the relationships within and among movement behaviours and several health indicators were completed and interpreted by a Guideline Development Panel. The systematic reviews that were conducted to inform the development of the guidelines, and the framework that was applied to develop the recommendations, followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. Complementary compositional analyses were performed using data from the Canadian Health Measures Survey to examine the relationships between movement behaviours and indicators of adiposity. A review of the evidence on the cost effectiveness and resource use associated with the implementation of the proposed guidelines was also undertaken. A stakeholder survey (n = 546), 10 key informant interviews, and 14 focus groups (n = 92 participants) were completed to gather feedback on draft guidelines and their dissemination.ResultsThe guidelines provide evidence-informed recommendations as to the combinations of light-, moderate- and vigorous-intensity physical activity, sedentary behaviours, and sleep that infants (<1 year), toddlers (1–2 years) and preschoolers (3–4 years) should achieve for a healthy day (24 h). Proactive dissemination, promotion, implementation, and evaluation plans were prepared to optimize uptake and activation of the new guidelines.ConclusionsThese guidelines represent a sensible evolution of public health guidelines whereby optimal health is framed within the balance of movement behaviours across the whole day, while respecting preferences of end-users. Future research should consider the integrated relationships among movement behaviours, and similar integrated guidelines for other age groups should be developed.Electronic supplementary materialThe online version of this article (10.1186/s12889-017-4859-6) contains supplementary material, which is available to authorized users.

BackgroundNew Canadian 24-Hour Movement Guidelines for the Early Years have been released in 2017. According to the guidelines, within a 24-h period, preschoolers should accumulate at least 180 min of physical activity (of which at least 60 min is moderate-to-vigorous physical activity), engage in no more than 1 h of screen time, and obtain between 10 and 13 h of sleep. This study examined the proportions of preschool-aged (3 to 4 years) Canadian children who met these new guidelines and different recommendations within the guidelines, and the associations with adiposity indicators.MethodsParticipants were 803 children (mean age: 3.5 years) from cycles 2–4 of the Canadian Health Measures Survey (CHMS), a nationally representative cross-sectional sample of Canadians. Physical activity was accelerometer-derived, and screen time and sleep duration were parent-reported. Participants were classified as meeting the overall 24-Hour Movement Guidelines if they met all three specific time recommendations for physical activity, screen time, and sleep. The adiposity indicators in this study were body mass index (BMI) z-scores and BMI status (World Health Organization Growth Standards).ResultsA total of 12.7% of preschool-aged children met the overall 24-Hour Movement Guidelines, and 3.3% met none of the three recommendations. A high proportion of children met the sleep duration (83.9%) and physical activity (61.8%) recommendations, while 24.4% met the screen time recommendation. No associations were found between meeting individual or combined recommendations and adiposity.ConclusionsVery few preschool-aged children in Canada (~13%) met all three recommendations contained within the 24-Hour Movement Guidelines. None of the combinations of recommendations were associated with adiposity in this sample. Future work should focus on identifying innovative ways to reduce screen time in this population, and should examine the associations of guideline adherence with health indicators other than adiposity.

BackgroundThe objective of this systematic review was to examine for the first time the associations between sleep duration and a broad range of health indicators in children aged 0 to 4 years.MethodsElectronic databases were searched with no limits on date or study design. Included studies (published in English or French) were peer-reviewed and met the a priori determined population (apparently healthy children aged 1 month to 4.99 years), intervention/exposure/comparator (various sleep durations), and outcome criteria (adiposity, emotional regulation, cognitive development, motor development, growth, cardiometabolic health, sedentary behaviour, physical activity, quality of life/well-being, and risks/injuries). The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Due to high levels of heterogeneity across studies, narrative syntheses were employed.ResultsA total of 69 articles/studies (62 unique samples) met inclusion criteria. Data across studies included 148,524 unique participants from 23 countries. The study designs were randomized trials (n = 3), non-randomized interventions (n = 1), longitudinal studies (n = 16), cross-sectional studies (n = 42), or longitudinal studies that also reported cross-sectional analyses (n = 7). Sleep duration was assessed by parental report in 70% of studies (n = 48) and was measured objectively (or both objectively and subjectively) in 30% of studies (n = 21). Overall, shorter sleep duration was associated with higher adiposity (20/31 studies), poorer emotional regulation (13/25 studies), impaired growth (2/2 studies), more screen time (5/5 studies), and higher risk of injuries (2/3 studies). The evidence related to cognitive development, motor development, physical activity, and quality of life/well-being was less clear, with no indicator showing consistent associations. No studies examined the association between sleep duration and cardiometabolic biomarkers in children aged 0 to 4 years. The quality of evidence ranged from “very low” to “high” across study designs and health indicators.ConclusionsDespite important limitations in the available evidence, longer sleep duration was generally associated with better body composition, emotional regulation, and growth in children aged 0 to 4 years. Shorter sleep duration was also associated with longer screen time use and more injuries. Better-quality studies with stronger research designs that can provide information on dose-response relationships are needed to inform contemporary sleep duration recommendations.Electronic supplementary materialThe online version of this article (10.1186/s12889-017-4850-2) contains supplementary material, which is available to authorized users.