Mark S. Tremblay

Senior Scientist, CHEO Research Institute

Professor Mark Tremblay has a Bachelor of Commerce degree in Sports Administration and a Bachelor of Physical and Health Education degree from Laurentian University. His graduate training was from the University of Toronto where he obtained his M.Sc. and Ph.D. from the Department of Community Health with a specialty in Exercise Science.

Dr. Tremblay is a Senior Scientist with the Healthy Active Living and Obesity Research (HALO) Research Group at the Children’s Hospital of Eastern Ontario Research Institute and Professor of Pediatrics in the Faculty of Medicine, University of Ottawa. He is a Fellow of the Canadian Society for Exercise Physiology, Fellow of the American College of Sports Medicine, Fellow of the Canadian Academy of Health Sciences, President of the Active Healthy Kids Global Alliance, Founder of the Sedentary Behaviour Research Network, President of Outdoor Play Canada, and Adjunct/Visiting Professor at five other universities on four continents.

Dr. Tremblay has published >600 scientific papers and book chapters in the areas of childhood obesity, physical activity measurement, exercise physiology, sedentary physiology, outdoor play and health surveillance. According to Scopus, his h-index is 100 and his published research has been cited >42,000, consistently placing him on the Clarivate list of highly cited researchers (top 1% in the world). He has delivered or coauthored over 1,000 scholarly conference presentations, including more than 150 invited and keynote addresses, in 22 different countries.

Dr. Tremblay received an honorary doctorate from Nipissing University, the Queen Elizabeth II Diamond Jubilee Medal, the Lawson Foundation 60th Anniversary Award, the Canadian Society for Exercise Physiology Honour Award and John Sutton Memorial Lecturer Award, the Victor Marchessault Advocacy Award from the Canadian Pediatric Society, the Vic Neufeld Mentorship Award in Global Health Research from the Canadian Coalition for Global Health Research, the International Network of Time-Use Epidemiologists Laureate Award, the Canadian Institutes of Health Research Trailblazer Award in Population and Public Health Research, and the Obesity Canada Distinguished Lecturer Award for his leadership contributions to healthy active living in Canada and around the world.

Dr. Tremblay’s most productive work has resulted from his 35-year marriage to his wife Helen, yielding four wonderful children.

Related News

Research Projects

  1. “Goldilocks days” for adolescent mental health: movement behaviour combinations for well-being, anxiety and depression by gender.


    The Dual Continua Model of mental health suggests two separate, but related, dimensions of mental health contribute to social, emotional and vocational/academic functioning (Westerhof & Keyes, 2010): 1) an illness dimension capturing the presence and severity of syndromal symptoms (e.g. internalizing symptoms, externalizing symptoms, psychosis) and 2) a positive well-being dimension capturing subjective feelings of well-being (e.g. perceiving meaning in life, satisfaction with social relationships, self-efficacy). Better functioning outcomes in both adults and youth are associated with reporting both low levels of illness symptoms and high levels of positive well-being, as opposed to individuals who just report one or the other (Butler, Patte, Ferro, & Leatherdale, 2019; Dumuid et al., 2022; Duncan, Patte, & Leatherdale, 2021; Keyes, 2002). Much of the research on mental illness symptoms in relation to movement behaviours has focused on reducing clinically significant symptoms or avoiding disease states (Mammen & Faulkner, 2013; Ravindran et al., 2018; Recchia et al., 2023). Nevertheless, even among individuals who do not meet diagnostic criteria for mental illness, subsyndromal levels of symptoms can impair functioning compared to those with lower levels of symptomology (Hirschfeld, 2001). Avoiding disease should not be the only goal of mental health promotion, promoting behaviours associated with an optimal state of mental health must be also considered.

  2. Prioritizing a research agenda on built environments and physical activity: a twin panel Delphi consensus process with researchers and knowledge users.


    Habitual physical activity (PA) improves health and well-being and helps to reduce the risk for injury, many chronic conditions and premature mortality [1, 2]. However, prevailing inactive lifestyles mean inadequate numbers of children and adults meet national and international PA guidelines for health benefits [3]. There is growing recognition that ecological models can contribute to enhancing understanding of the facilitators and barriers to PA, notably as related to the influence of various aspects of the built environments on individual and social behaviours [4]. Built environments reflect the design and layout of the communities in which people live, work, learn and play and include land use for buildings and grounds, road and transit infrastructure, and parks and recreation facilities. In their review of the literature, Sallis et al. framed that the built environment exerts influence on PA behaviours in four key life domains: leisure/recreation, work/education, transportation, and household [4]. While the need for multiple levels of built environment interventions and policies related to PA are widely acknowledged, continuing challenges include identification of the optimal combination of study designs, target groups, built environment attributes, and policy processes to elevate understanding of which environmental changes will be most beneficial for PA promotion within and across populations [3].

  3. Exercise breaks prevent attenuation in cerebrovascular function following an acute bout of uninterrupted sitting in healthy children.


    Childhood sedentary behaviour was already at alarming levels before the COVID-19 pandemic (Saunders, 2014); however, as children have transitioned to a largely seated digital environment for schooling and social interaction during country-wide lockdowns and restrictions, sedentary time increased by an average of 160 min per day (Runacres et al., 2021). The health impacts of such increases in sedentary behaviour in childhood have yet to be fully elucidated. This is worrisome, given evidence that excessive sedentary time is an independent risk factor for cardiovascular disease in both children and adults (Hamilton et al., 2008; Saunders et al., 2014).

  4. Children and youth’s movement behaviours differed across phases and by geographic region throughout the COVID-19 pandemic in Nova Scotia, Canada: An explanatory sequential mixed-methods study.


    Nova Scotia also provides a unique case study due to it being the region’s most populated (~ 1 million residents) and culturally diverse population. Additionally, its advantageous geography of being a maritime province, relatively separate from other provinces and territories, allowed Nova Scotia to have control over its entry points to implement strict boarder controls and limit the introduction of new COVID-19 cases from outside the area. The surrounding Atlantic provinces were also entered into an agreement with Nova Scotia known as the “Atlantic Bubble” from June 2020 until April 2021, allowing residents to travel freely within the region without quarantine requirements. Internationally, this is comparable to other regions or countries who implemented similar practices, such as fully-closed borders or travel zones, facilitating low transmission, safe travel, and economic benefits, including the Australia/New Zealand Travel Bubble the Baltic Travel Bubble of Estonia, Latvia, and Lithuania. Thus, potentially contributing to evidence on these models in the mitigation of virus transmission while also preserving access to areas and amenities related to favourable movement behaviours.

  5. Unmasking the political power of physical activity research: Harnessing the ‘apolitical-ness’ as a catalyst for addressing the challenges of our time


    Physical activity, particularly in the form of sports, has been suggested as a valuable tool for crime prevention, community integration, and social cohesion in disciplines such as humanities, sociology, and criminal justice studies.9 However, in physical activity scholarship, the predominant focus has often been on investigating correlates, determinants, and health outcomes of physical activity, driven by quantitative research with a strong biomedical emphasis at an individual level. As a result, the potential benefits of physical activity in positively addressing macrolevel challenges have received comparatively less attention. Nevertheless, Bailey et al’s10,11 work published in the Journal of Physical Activity and Health in early 2010s brought attention to physical activity as an often overlooked investment for human and social capital. Their work introduced the human capital model,11 which recognizes the underappreciated value of physical activity despite its importance for overall well-being beyond health benefits. The model proposes that different types of “capitals” are generated through physical activity, encompassing emotional, financial, individual, intellectual, physical, and social domains. The authors argue that investing in these capitals, particularly during early life stages, can yield significant individual and social rewards. It is worth noting that although we appreciate the deliberate effort made by these authors to positively frame the multifaceted benefits of physical activity, their suggested reframing of “physical activity” as a solution remains closely aligned with neoliberal ideology prevalent in the dominant public health discourse.