Richard Larouche

Systematic review of sedentary behaviour and health indicators in school-aged children and youth

Accumulating evidence suggests that, independent of physical activity levels, sedentary behaviours are associated with increased risk of cardio-metabolic disease, all-cause mortality, and a variety of physiological and psychological problems. Therefore, the purpose of this systematic review is to determine the relationship between sedentary behaviour and health indicators in school-aged children and youth aged 5-17 years. Online databases (MEDLINE, EMBASE and PsycINFO), personal libraries and government documents were searched for relevant studies examining time spent engaging in sedentary behaviours and six specific health indicators (body composition, fitness, metabolic syndrome and cardiovascular disease, self-esteem, pro-social behaviour and academic achievement). 232 studies including 983,840 participants met inclusion criteria and were included in the review. Television (TV) watching was the most common measure of sedentary behaviour and body composition was the most common outcome measure. Qualitative analysis of all studies revealed a dose-response relation between increased sedentary behaviour and unfavourable health outcomes. Watching TV for more than 2 hours per day was associated with unfavourable body composition, decreased fitness, lowered scores for self-esteem and pro-social behaviour and decreased academic achievement. Meta-analysis was completed for randomized controlled studies that aimed to reduce sedentary time and reported change in body mass index (BMI) as their primary outcome. In this regard, a meta-analysis revealed an overall significant effect of -0.81 (95% CI of -1.44 to -0.17, p = 0.01) indicating an overall decrease in mean BMI associated with the interventions. There is a large body of evidence from all study designs which suggests that decreasing any type of sedentary time is associated with lower health risk in youth aged 5-17 years. In particular, the evidence suggests that daily TV viewing in excess of 2 hours is associated with reduced physical and psychosocial health, and that lowering sedentary time leads to reductions in BMI.

Associations Between Active School Transport and Physical Activity, Body Composition, and Cardiovascular Fitness: A Systematic Review of 68 Studies

BACKGROUND The impact of active school transport (AST) on daily physical activity (PA) levels, body composition and cardiovascular fitness remains unclear. METHODS A systematic review was conducted to examine differences in PA, body composition and cardiovascular fitness between active and passive travelers. The Medline, PubMed, Embase, PsycInfo, and ProQuest databases were searched and 10 key informants were consulted. Quality of evidence was assessed with GRADE and with the Effective Public Health Practice Project tool for quantitative studies. RESULTS Sixty-eight different studies met the inclusion criteria. The majority of studies found that active school travelers were more active or that AST interventions lead to increases in PA, and the quality of evidence is moderate. There is conflicting, and therefore very low quality evidence, regarding the associations between AST and body composition indicators, and between walking to/from school and cardiovascular fitness; however, all studies with relevant measures found a positive association between cycling to/from school and cardiovascular fitness; this evidence is of moderate quality. CONCLUSION These findings suggest that AST should be promoted to increase PA levels in children and adolescents and that cycling to/ from school is associated with increased cardiovascular fitness. Intervention studies are needed to increase the quality of evidence.

Acute sedentary behaviour and markers of cardiometabolic risk: a systematic review of intervention studies.

North Americans spend half their waking hours engaging in sedentary behaviour. Although several recent interventions suggest that short bouts of uninterrupted sedentary behaviour may result in acute increases in cardiometabolic risk, this literature has not been reviewed systematically. This study performed a systematic review of the impact of uninterrupted sedentary behaviour lasting ≤7 days on markers of cardiometabolic risk (insulin sensitivity, glucose tolerance, and fasting insulin, glucose, and lipid levels) in humans. Interventions were identified through systematic searches of Medline and Embase and screened by 2 independent reviewers. A total of 25 interventions were identified that examined the impact of imposed sedentary behaviour on biomarkers of interest. The majority of these studies focused on healthy young men, with very little identified research on females or other age groups. We found consistent, moderate quality evidence that uninterrupted sedentary behaviour ≤7 days results in moderate and deleterious changes in insulin sensitivity, glucose tolerance, and plasma triglyceride levels. In contrast, there is inconsistent, very low-quality evidence linking uninterrupted sedentary behaviour with changes in insulin, glucose, and HDL- and LDL-cholesterol levels. These findings suggest that uninterrupted bouts of sedentary behaviour should be avoided in order to prevent or attenuate transient increases in metabolic risk.

Position Statement on Active Outdoor Play

A diverse, cross-sectorial group of partners, stakeholders and researchers, collaborated to develop an evidence-informed Position Statement on active outdoor play for children aged 3–12 years. The Position Statement was created in response to practitioner, academic, legal, insurance and public debate, dialogue and disagreement on the relative benefits and harms of active (including risky) outdoor play. The Position Statement development process was informed by two systematic reviews, a critical appraisal of the current literature and existing position statements, engagement of research experts (N = 9) and cross-sectorial individuals/organizations (N = 17), and an extensive stakeholder consultation process (N = 1908). More than 95% of the stakeholders consulted strongly agreed or somewhat agreed with the Position Statement; 14/17 participating individuals/organizations endorsed it; and over 1000 additional individuals and organizations requested their name be listed as a supporter. The final Position Statement on Active Outdoor Play states: “Access to active play in nature and outdoors—with its risks— is essential for healthy child development. We recommend increasing children’s opportunities for self-directed play outdoors in all settings—at home, at school, in child care, the community and nature.” The full Position Statement provides context for the statement, evidence supporting it, and a series of recommendations to increase active outdoor play opportunities to promote healthy child development.

Active transportation and adolescents' health: the Canadian Health Measures Survey

BACKGROUND Active transportation (AT; e.g., walking and cycling) is increasingly promoted to increase youth physical activity (PA). Most previous research focused solely on school trips, and associations among AT and cardiovascular risk factors have seldom been examined in adolescents. PURPOSE To address these important research gaps using data from the nationally representative 2007-2009 Canadian Health Measures Survey. METHODS A total of 1,016 adolescents aged 12-19 years reported their weekly time spent utilitarian walking and cycling, and wore an Actical accelerometer for 7 days. They underwent a series of physical tests (measures of fitness, body composition, blood pressure, and blood sampling) following standardized protocols. In 2013, differences in PA and health-related outcomes across levels of walking and cycling were assessed with ANCOVA analyses adjusted for age, gender, parental education, and usual daily PA. RESULTS Greater walking and cycling time was associated with higher moderate-to-vigorous PA (MVPA). Compared to adolescents reporting walking 1-5 hours/week, those reporting <1 hour/week had lower waist circumference and total cholesterol/high-density lipoprotein (HDL) ratio and higher glycohemoglobin; those reporting >5 hours/week had better grip strength, lower total cholesterol, and total cholesterol/HDL ratio. Compared to adolescents reporting no cycling, those reporting ≥1 hour/week accumulated more light PA, had greater aerobic fitness, and lower BMI, waist circumference, and total cholesterol/HDL ratio; those who reported cycling <1 hour/week had lower total cholesterol. CONCLUSIONS Utilitarian walking and cycling were associated with higher daily MVPA in youth. Cycling was associated with a more consistent pattern of health benefits than walking.

Are We Driving Our Kids to Unhealthy Habits? Results of the Active Healthy Kids Canada 2013 Report Card on Physical Activity for Children and Youth

This article examines the time trends in patterns of school travel mode among Canadian children and youth to inform the Active Transportation (AT) indicator of the 2013 Active Healthy Kids Canada Report Card on Physical Activity for Children and Youth. The AT grade was assigned based on a comprehensive synthesis of the 2000 and 2010 Physical Activity Monitor studies from the Canadian Fitness and Lifestyle Research Institute and the 1992, 1998, 2005, and 2010 General Social Survey from Statistics Canada. The results showed that in 2013, AT was graded a D, because less than half of Canadian children and youth used only active modes of transportation to get to and from school. The proportion of Canadian children and youth who used only inactive modes of transportation for school travel increased significantly from 51% to 62% over the last decade. Children and youth from larger communities and those with lower household income levels were significantly more likely to use AT than those living in smaller communities and those in higher income households, respectively. In conclusion, motorized transport for school travel has increased steadily over the last decade across Canada. Regional and socio-demographic disparities should be considered in efforts to increase the number of children using AT.

A systematic review of active transportation research in Africa and the psychometric properties of measurement tools for children and youth

BackgroundPrevious systematic reviews indicate that active transportation (AT; the use of non-motorized travel modes such as walking, running and cycling) is an important source of daily physical activity (PA). However, no previous systematic review has examined travel behaviours among African children and youth or the psychometric properties of measurement tools used among children and youth worldwide.MethodsStudies on AT among African children and youth (aged 5-17 years) were identified through 1) the MEDLINE and Embase databases; 2) manual searches of six African journals that are not indexed in these databases; and 3) the articles included in a previous systematic review on PA among children and youth in Sub-Saharan Africa. Second, literature on the psychometric properties of measurement tools for children and youth was searched using the MEDLINE, Embase, Cochrane Central Register of Controlled Trials, PsycInfo, SportDiscus, and Health and Psychosocial Instruments databases. Study quality was assessed with a modified version of the Downs and Black checklist.ResultsTwenty studies reported original data on AT among African children and youth. This evidence suggests that rates of AT to/from school are lower in urban areas and in youth attending higher SES schools. Two population-based studies reported rates of AT ranging between 19.8% and 66.6% in multiple countries. Studies conducted in Africa seldom examined non-school travel and only one reported data on the psychometric properties of their measures of travel behaviours. Nineteen studies conducted predominantly in high-income countries provided psychometric data. Child and parent reports were used in 17 studies, and these measures generally showed substantial to almost perfect test-retest reliability and convergent validity for school trips. Limited information was available regarding non-school trips. Objective measures of travel behaviours have been used much less often, and further validity and reliability assessments are warranted.ConclusionThese findings emphasize a need for more research examining travel behaviours among African children and youth, particularly for non-school travel. Further research is needed to develop valid and reliable measures of non-school travel and to examine their psychometric properties in the African context. These measures could then be used to evaluate AT promotion interventions.

Too far to walk or bike

Only 25–35% of Canadian children and youth regularly engage in active transportation (AT; e.g., non-motorized travel modes such as walking and cycling) to/from school. Previous research shows that distance between home and school is the strongest barrier to AT. Based on social ecological theory, we describe several strategies to overcome this barrier. At the individual level, children and youth could engage in AT to/from destinations such as parks, shops, friends’ and family members’ residence, and sport fields which may be located closer than their school. Parents who drive their kids to/from school could drop them within a “walkable” distance so that they can walk for the remainder of the trip. Partnerships could be developed between schools and other nearby institutions that would allow cars and buses to use their parking lot temporarily so that children could do a portion of the school trip on foot. Developing a well-connected network of sidewalks along low traffic streets can also facilitate AT. At the policy level, decisions regarding school location have a direct influence on distance. Finally, social marketing campaigns could raise awareness about strategies to incorporate AT into one’s lifestyle, and encourage parents to reconsider what constitutes a “walkable” distance.RésuméSeulement 25–35% des enfants et adolescents canadiens font régulièrement du transport actif (TA; soit l’utilisation de modes de transport non-motorisés comme la marche et le vélo) pour se rendre à l’école et en revenir. Des études précédentes montrent que la distance entre l’école et la maison est la principale barrière au TA. D’après le modèle socio-écologique, nous décrivons plusieurs stratégies pour surmonter cette barrière. Au niveau individuel, les jeunes pourraient faire du TA pour aller à des destinations situées plus près de leur domicile comme au parc, au magasin, à la résidence de leurs amis ou de membres de leur famille ou au terrain de sport. Les parents qui conduisent leur enfant en voiture pourraient se stationner près de l’école pour effectuer le reste du trajet à pied. Des partenariats pourraient être développés entre les écoles et des institutions avoisinantes qui permettraient que les voitures et autobus utilisent leur stationnement temporairement pour que les jeunes puissent faire une partie du trajet à pied. Le développement d’un réseau de trottoirs bien connectés le long de rues avec une faible circulation automobile pourrait également favoriser le TA. Au niveau politique, les décisions quant à l’emplacement des écoles ont un impact direct sur la distance. Finalement, des campagnes de marketing social pourraient sensibiliser les gens aux stratégies pour incorporer le TA à ses habitudes de vie, et encourager les parents à reconsidérer ce que représente une distance ªmarchable«.

Active school transport and weekday physical activity in 9–11-year-old children from 12 countries

OBJECTIVES Active school transport (AST) may increase the time that children spend in physical activity (PA). This study examined relationships between AST and weekday moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), sedentary time (SED) and total activity during naturally organized time periods (daily, before school, during school and after school) in a sample of children from 12 countries. METHODS The sample included 6224 children aged 9-11 years. PA and sedentary time were objectively measured using Actigraph accelerometers. AST was self-reported by participants. Multilevel generalized linear and logistic regression statistical models were used to determine associations between PA, SED and AST across and within study sites. RESULTS After adjustment for age, highest parental educational attainment, BMI z-score and accelerometer wear time, children who engaged in AST accumulated significantly more weekday MVPA during all studied time periods and significantly less time in LPA before school compared with children who used motorized transport to school. AST was unrelated to time spent in sedentary behaviors. Across all study sites, AST was associated with 6.0 min (95% confidence interval (CI): 4.7-7.3; P<0.0001) more of weekday MVPA; however, there was some evidence that this differed across study sites (P for interaction=0.06). Significant positive associations were identified within 7 of 12 study sites, with differences ranging from 4.6 min (95% CI: 0.3-8.9; P=0.04, in Canada) to 10.2 min (95% CI: 5.9-14.4; P<0.0001, in Brazil) more of daily MVPA among children who engaged in AST compared with motorized transport. CONCLUSIONS The present study demonstrated that AST was associated with children spending more time engaged in MVPA throughout the day and less time in LPA before school. AST represents a good behavioral target to increase levels of PA in children.

Influence of birth quarter on the rate of physical activities and sports participation.

Abstract The purpose of this study was to assess the potential influence of birth quarter on the frequency of physical activity and participation in specific activities during adulthood. We used data from one national and one provincial survey, the 2005 Canadian Community Health Survey and the 1998 Quebec Social and Health Survey (Enquête sociale et de santé du Québec) respectively. We analysed the distribution of participants at each level of practice of a given leisure activity and work-related physical activity. In the Canadian Community Health Survey, a relative age effect was found for participation in soccer in the 25- to 60-year-old population. However, for volleyball, a significant relative age effect was also observed but with over-representation of the last quarters of the year for the whole population and for men aged 12–60 years. In the Quebec Social and Health Survey, significant differences in the frequency of distribution without a relative age effect were revealed for participation in womens ice hockey, work-related physical activity level, and stage of change for physical activity. Overall, the data indicate that the systematic relative age effect reported in other studies for some competitive sports, such as ice hockey and soccer, is not as prevalent in leisure physical activities during adulthood. This may reflect lower competitive selection and attrition in population physical activity compared with competitive sports in younger athletes.