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This analysis aimed to (1) identify longitudinal joint trajectories of participation in organized and unorganized physical activity contexts, and level of daily moderate-to-vigorous physical activity (MVPA) and (2) assess whether basic psychological need satisfaction during adolescence differentiates between membership in different physical activity trajectories. Participants (n = 888; 56% girls) reported their involvement in 36 different physical activities, level of MVPA, and their perceived satisfaction of competence, autonomy, and relatedness satisfaction in physical activity up to three times per year, over 8 years (from ages 10 to 17 years). Group-based multi-trajectory models were used to identify longitudinal joint trajectories of physical activity participation. We estimated a multinomial logistic regression model for membership in a physical activity trajectory by including individual-level intercepts and slopes for each psychological need obtained using mixed models over the 24 cycles modelized as natural cubic splines. Five longitudinal trajectory groups emerged: Non-participants, Dropouts, Active in unorganized physical activities, Active in organized physical activities, and Active through a variety of activities. Relative to Non-participants, we identify a dose-response relationship in baseline competence and membership in the higher active trajectory groups. In addition, a positive change in competence in early adolescence predicted membership in all three Active trajectory groups., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: Children's active travel to and from school (AST) and children's independent mobility (CIM) are consistently positively associated with physical activity (PA); however, few researchers have investigated associations between objective measures of the environment and indicators of AST and CIM in national samples., Methods: A national sample of 2,067 Canadian parents of 7- to 12-year-old children was recruited in December 2020. Regression analyses were used in 2023 to assess the association between geographic information system measures of park density, blue space, population density, greenspace, intersection density, and CIM and AST to and from school., Results: Children in areas with high versus low park density (>0.025 vs. ≤0.025) had higher odds of travel to school via active modes (OR: 1.47 [1.14, 1.91], p=0.003). Children in neighborhoods in the highest quartile for neighborhood greenspace (Normalized Difference Vegetation Index) were more likely to travel to home actively than those in areas of lower greenspace (OR: 1.70 [1.18, 2.45], p=0.004). On average, children living in areas in the highest versus the lowest quartile for intersection density were more likely to engage in AST to (OR: 2.43 [1.58, 3.75], p<0.001) and from (OR: 2.77 [1.80, 4.29], p<0.001) school., Conclusions: The observed associations underscore a need for city planners and policymakers to ensure sufficient access to parks and neighborhood greenspace, especially if findings are confirmed in longitudinal studies. More research is needed to investigate the role of intersection density in supporting AST and CIM., (Copyright © 2023 American Journal of Preventive Medicine. All rights reserved.)

Background: Active school transportation (AST) is an important source of physical activity for children and a potentially important climate change mitigation strategy. However, few studies have examined factors associated with AST in the context of the COVID-19 pandemic., Methods: We used baseline data from a longitudinal survey to investigate correlates of AST during the second wave of COVID-19 (December 2020). We collected survey data from 2291 parents of 7- to 12-year-olds across Canada and linked this information with data on neighborhood walkability and weather from national databases. We assessed potential correlates representing multiple levels of influence of the social-ecological model. We used gender-stratified binary logistic regression models to determine the correlates of children's travel mode to/from school (dichotomized as active vs motorized), while controlling for household income. We examined the correlates of travel mode for both the morning and afternoon trips., Results: Consistent correlates of AST among Canadian children during the COVID-19 pandemic included greater independent mobility, warmer outdoor temperature, having a parent who actively commuted to work or school, living in a household owning fewer vehicles, and living in a more walkable neighborhood. These findings were largely consistent between boys and girls and between morning and afternoon school trips., Conclusions: Policymakers, urban planners, and public health workers aiming to promote AST should focus on these correlates while ensuring that neighborhoods are safe for children. Future research should monitor the prevalence and correlates of AST as COVID-19 restrictions are removed.

Independent mobility (IM) is associated with children's physical activity and indicators of social, motor, and cognitive development. We surveyed Canadian parents of 7- to 12-year-olds (n = 2291) about social-ecological correlates of IM in the second wave of COVID-19 (December 2020). We used multi-variable linear regression models to identify correlates of children's IM. Our final model (R 2  = 0.353) included four individual-, eight family-, two social environment- and two built environment-level variables. The correlates of boys' and girls' IM were similar. Our findings suggest that interventions to support children's IM in a pandemic context should target multiple levels of influence., Competing Interests: Declaration of competing interest RL receives royalties from Elsevier for his book, Children's Active Transportation. Other authors have no interests to declare., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Both spending time outdoors and participating in physical activity improve mental health. Given that the outdoor environment provides an ideal location for physical activity, better understanding of the relationships among time spent outdoors, physical activity and positive mental health is needed to help guide interventions. The aim was to examine if physical activity moderates or mediates the relationship between outdoor time and positive mental health. Two-hundred-forty-two participants (15 ± 1 years old, 59% girls) from New Brunswick, Canada were included in the current analysis. Youth self-reported time spent outdoors and moderate-to-vigorous physical activity (MVPA) three times between October 2016 and June 2017. Data on their mental health were collected in October 2017. Values of outdoor time and MVPA were averaged across the three time points to represent the exposure and mediator variables, respectively. Mental health, dichotomized as flourishing/not flourishing, was the outcome in the mediation analysis. An interaction term tested if the mediation effect depended on outdoor time. Analyses were undertaken in 2019 using the mediation package in R. In univariate analyses, both MVPA (p < 0.001) and outdoor time (p = 0.05) were positive predictors of flourishing mental health. In mediation analyses, a small indirect mediation (OR: 1.02, 95% CI: 1.01-1.04) and no direct (1.00, 0.98-1.05) effect were noted, suggesting that MVPA mediates the effect of outdoor time on positive mental health. This effect did not vary as a function of outdoor time (interaction: 1.00, 0.99-1.01). Physical activity mediates the relationship between outdoor time and positive mental health. Outdoor time could promote positive mental health among youth through increases in physical activity., (© 2019 The Authors.)

Cities are dependent on their upstream watersheds for storage and gradual release of water into river systems. These watersheds act as important flood mitigation infrastructure, providing an essential ecosystem service. In this paper we use metrics from the WaterWorld model to examine the flood management-relevant natural infrastructure of the upstream watersheds of selected global cities. These metrics enable the characterisation of different types, magnitudes and geographical distributions of potential natural flood storage. The storages are categorised as either green (forest canopy, wetland and soil) or blue (water body and floodplain) storages and the proportion of green to blue indicates how different city upstream basin contexts provide different types and levels of storage which may buffer flood risk. We apply the WaterWorld method for examining flood risk as the ratio of accumulated modelled annual runoff volume to accumulated available green and blue water storage capacity. The aim of these metrics is to highlight areas where there is more runoff than storage capacity and thus where the maintenance or restoration of further natural infrastructure (such as canopy cover, wetlands and soil) could aid in storing more water and thus better alleviate flood risks. Such information is needed by urban planners, city authorities and governments to help prepare cities for climate change impacts., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Obesity in youth increases the risk of type 2 diabetes (T2D), and both are risk factors for neurocognitive deficits. Exercise attenuates the risk of obesity and T2D while improving cognitive function. In adults, these benefits are associated with the actions of the brain-derived neurotrophic factor (BDNF), a protein critical in modulating neuroplasticity, glucose regulation, fat oxidation, and appetite regulation in adults. However, little research exists in youth. This study examined the associations between changes in diabetes risk factors and changes in BDNF levels after 6 months of exercise training in adolescents with obesity. The sample consisted of 202 postpubertal adolescents with obesity (70% females) aged 14-18 years who were randomized to 6 months of aerobic and/or resistance training or nonexercise control. All participants received a healthy eating plan designed to induce a 250/kcal deficit per day. Resting serum BDNF levels and diabetes risk factors, such as fasting glucose, insulin, homeostasis model assessment (HOMA-B-beta cell insulin secretory capacity) and (HOMA-IS-insulin sensitivity), and hemoglobin A1c (HbA1c), were measured after an overnight fast at baseline and 6 months. There were no significant intergroup differences on changes in BDNF or diabetes risk factors. In the exercise group, increases in BDNF were associated with reductions in fasting glucose ( β  = -6.57, SE = 3.37, p = 0.05) and increases in HOMA-B ( β  = 0.093, SE = 0.03, p = 0.004) after controlling for confounders. No associations were found between changes in diabetes risk factors and BDNF in controls. In conclusion, exercise-induced reductions in some diabetes risk factors were associated with increases in BDNF in adolescents with obesity, suggesting that exercise training may be an effective strategy to promote metabolic health and increases in BDNF, a protein favoring neuroplasticity. This trial is registered with ClinicalTrials.gov NCT00195858, September 12, 2005 (funded by the Canadian Institutes of Health Research).

The aim of this study was to develop and validate an electronic questionnaire, the Electronic Maternal Health Survey ( EMat Health Survey ), related to women's knowledge and perceptions of the current gestational weight gain guidelines (GWG), as well as pregnancy-related health behaviours. Constructs addressed within the questionnaire include self-efficacy, locus of control, perceived barriers, and facilitators of physical activity and diet, outcome expectations, social environment and health practices. Content validity was examined using an expert panel ( n = 7) and pilot testing items in a small sample ( n = 5) of pregnant women and recent mothers (target population). Test re-test reliability was assessed among a sample ( n = 71) of the target population. Reliability scores were calculated for all constructs ( r and intra-class correlation coefficients (ICC)), those with a score of >0.5 were considered acceptable. The content validity of the questionnaire reflects the degree to which all relevant components of excessive GWG risk in women are included. Strong test-retest reliability was found in the current study, indicating that responses to the questionnaire were reliable in this population. The EMat Health Survey adds to the growing body of literature on maternal health and gestational weight gain by providing the first comprehensive questionnaire that can be self-administered and remotely accessed. The questionnaire can be completed in 15-25 min and collects useful data on various social determinants of health and GWG as well as associated health behaviours. This online tool may assist researchers by providing them with a platform to collect useful information in developing and tailoring interventions to better support women in achieving recommended weight gain targets in pregnancy., Competing Interests: The authors declare no conflict of interest.