Mark S. Tremblay’s research while affiliated with Carleton University and other places

Background : Social climate refers to the general feelings, norms, and opinions in a society and may be affected by experiences of discrimination. This study examined whether experiences of discrimination are associated with the social climate of physical (in)activity and support for policies addressing dual benefits of physical activity (PA) and climate change. Methods : Data from the 2023 Social Climate Survey were used (n = 1950; ≥18 y). Adherence to PA guidelines, perceived importance of PA, social norms, and support for 8 policy actions addressing dual benefits were each regressed on experiences of discrimination. Results : Experiencing discrimination was not associated with the importance of PA, causal attribution of physical inactivity (individual vs external), adherence to PA guidelines, or policy support addressing PA and climate change. However, experiencing discrimination was associated with social norms that are favorable to PA: seeing children playing actively outdoors (odds ratio [OR]: 1.04; 95% CI, 1.02–1.06), perceiving that half of people their age meeting PA guidelines (OR: 1.04; 95% CI, 1.02–1.06), agreeing with societal disapproval of physical inactivity (OR: 1.03; 95% CI, 1.01–1.06), and having important people (eg, family/friends) meeting PA guidelines (OR: 1.10; 95% CI, 1.08–1.12). Conclusions : Unlike structural discrimination, interpersonal experiences of discrimination may not shape the perceived importance of and engagement in PA. However, experiencing discrimination may be associated with an individual’s perceptions of their social environment, including how they observe and interpret the behaviors of others within their community. Generally strong support for policies addressing dual benefits, regardless of experiences with discrimination, aligns well with the planetary health agenda.

Background Sleep, sedentary behaviour, physical activity, and the composition of these movement behaviours across the 24-h day are associated with cognitive function in early years children. This study used a Goldilocks day compositional data analysis approach to identify the optimal duration of sleep, sedentary behaviour, light physical activity, and moderate-to-vigorous physical activity associated with desired cognitive function outcomes in early years children. Methods This cross-sectional study included 858 children aged 2.8–5.5 years from the Sleep and Activity Database for the Early Years. 24-h movement behaviours (sleep, sedentary behaviour, light physical activity, moderate-to-vigorous physical activity) were measured using ActiGraph accelerometers. Cognitive function was measured using three tasks from the Early Years Toolbox: visual-spatial working memory, response inhibition, and expressive vocabulary. A Goldilocks day compositional data analysis approach was used in R software to identify the optimal time-use compositions associated with the best 10% of the cognitive function scores. Results The movement behaviour composition and the relative time spent in sleep and sedentary behaviour but not different intensities of physical activity were significantly associated with working memory (P ≤ 0.01). The movement behaviour composition and relative time spent in sleep, sedentary behaviour, and different intensities of physical activity were not significantly associated with response inhibition or expressive vocabulary (P > 0.2). Therefore, optimal time use was only determined for working memory. Optimal daily durations for working memory were observed with 11:00 (hr:min) of sleep, 5:42 of sedentary behaviour, 5:06 of light physical activity, and 2:12 of moderate-to-vigorous physical activity. Conclusion Working memory was the only cognitive function outcome related to the 24-h movement behaviour composition. Optimal sleep for working memory was consistent with current recommended durations, while optimal moderate-to-vigorous physical activity greatly exceeded minimal recommended levels. Optimal sedentary behaviour was longer and light physical activity was shorter than the sample average.

Background Child growth influences future health and learning. School readiness refers to a child's ability to meet developmental expectations at school entry. The association of early growth rate and patterns with school readiness remains unknown. Objective To determine the association of child body mass index (BMI) growth with school readiness in a cohort of young children. Methods A prospective cohort study (2015–2022) was conducted in children 0–6 years enrolled in the TARGet Kids! research network in Toronto, Canada. Two analytical approaches were used to measure growth using child weight and height/length data between 0 and 4 years: (i) age‐ and sex‐standardised BMI (zBMI) growth rate per year using a piecewise linear model; and (ii) distinct zBMI trajectories using latent class mixed models. School readiness (4–6 years) was measured using teacher‐completed Early Development Instrument (EDI). Robust Poisson models and marginal linear models using generalised estimating equations were used adjusting for confounders identified a priori. Results In this study of 1077 children (mean age at EDI completion: 4.8 years; 52.6% male) with 6415 zBMI measurements, mean growth rate was 0.65 zBMI units/year (0–2 years) and −0.11 zBMI units/year (2–4 years). Two distinct zBMI trajectories were identified: the stable trajectory and the catch‐up trajectory. There was insufficient evidence that zBMI growth rates (risk ratio 1.10, 95% confidence interval 0.78, 1.55 for 0–2 years; risk ratio 0.71, 95% confidence interval 0.32, 1.57 for 2–4 years) or trajectories (risk ratio 1.05, 95% confidence interval 0.82, 1.35, catch‐up trajectory vs. stable trajectory) were associated with school readiness. Conclusions No association was found between BMI growth and school readiness. School readiness may be more impacted by factors directly related to obesity or adiposity at the time of EDI measurement rather than growth.

Background Insufficient physical activity, excessive screen time and short sleep duration among young children are global public health concerns; however, data on prevalence of meeting World Health Organisation 24‐h movement behaviour guidelines for 3–4‐year‐old children in low‐ and middle‐income countries (LMICs) are limited, and it is unknown whether urbanisation is related to young children's movement behaviours. The present study examined differences in prevalence of meeting 24‐h movement behaviour guidelines among 3–4‐year‐old children living in urban versus rural settings in LMICs. Methods The SUNRISE Study recruited 429, 3–4‐year‐old child/parent dyads from 10 LMICs. Children wore activPAL accelerometers continuously for at least 48 h to assess their physical activity and sleep duration. Screen time and time spent restrained were assessed via parent questionnaire. Differences in prevalence of meeting guidelines between urban‐ and rural‐dwelling children were examined using chi‐square tests. Results Physical activity guidelines were met by 17% of children (14% urban vs. 18% rural), sleep guidelines by 57% (61% urban vs. 54% rural), screen time guidelines by 50% (50% urban vs. 50% rural), restrained guidelines by 84% (81% urban vs. 86% rural) and all guidelines combined by 4% (4% urban vs.4% rural). We found no significant differences in meeting the guidelines between urban and rural areas. Conclusions Only a small proportion of children in both rural and urban settings met the WHO 24‐h movement guidelines. Strategies to improve movement behaviours in LMICs should consider including both rural and urban settings.

Purpose : The purpose of this study is to analyze the associations between participation in physical education (PE) classes and days with ≥60 minutes of moderate- to vigorous-intensity physical activity (MVPA) using different reference categories for participation in PE. Methods : We used self-reported data from 284,820 adolescents. Results : When no participation in PE was the reference, participation on 1 (prevalence ratio [PR] = 1.15 [1.12–1.18]), 2 (PR = 1.24 [1.20–1.27]), 3 to 4 (PR = 1.32 [1.28–1.36]), and ≥5 days per week (PR = 1.8 [1.33–1.43]) increased frequency of days of ≥60 minutes of MVPA. Participating in PE on 2 (PR = 1.07 [1.02–1.09]), 3 to 4 (PR = 1.15 [1.12–1.18]), and ≥5 days per week (PR = 1.18 [1.15–1.22]) increased the days of ≥60 minutes of MVPA when participation in PE classes on 1 days per week was the reference. When participation in PE on 2 days per week was the reference, participation in PE classes on 3 to 4 (PR = 1.07 [1.04–1.09]) and ≥5 days per week (PR = 1.12 [1.09–1.15]) increased the days of ≥60 minutes of MVPA. Participating in PE classes on ≥5 days per week increased the days of ≥60 minutes of MVPA (PR = 1.05 [1.03–1.07]) when participation on 3 to 4 days per week was the reference. Conclusions : For those with no participation in PE classes, the addition of any PE classes could positively impact the weekly frequency of days of ≥60 minutes of MVPA. Even in countries/territories with large coverage of participation in PE classes, promoting more PE classes could be useful to increase physical activity.