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. Measuring severe obesity in pediatrics using body mass index‑derived metrics from the Centers for Disease Control and Prevention and World Health Organization: a secondary analysis of CANadian Pediatric Weight management Registry (CANPWR) data.


    To examine the (i) relationships between various body mass index (BMI)-derived metrics for measuring severe obesity (SO) over time based the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) references and (ii) ability of these metrics to discriminate children and adolescents based on the presence of cardiometabolic risk factors. In this cohort study completed from 2013 to 2021, we examined data from 3- to 18-year-olds enrolled in the CANadian Pediatric Weight management Registry.

  2. Prevalence and correlates of meeting the Canadian 24-hour movement guidelines among a sample of Canadian parents during the COVID-19 pandemic.


    Canada’s 24-hour movement guidelines for adults (aged 18–64 years) provide evidence-based recommendations for moderate­-to-vigorous physical activity (MVPA; ≥150 min/week), sedentary behaviour (SB; ≤8 h/day, including ≤ 3 h/day of recreational screen time) and sleep (7 to 9 h/day) [1]. A healthy 24-hour movement profile, comprised of greater physical activity (PA), less SB and sufficient sleep, is associated with a decreased risk of all-cause mortality and numerous non-communicable diseases including cardiovascular disease, type 2 diabetes, several types of cancer, depression, and anxiety disorders [2,3,4,5,6]. Using a representative sample of Canadian adults, a recent study using pre-COVID-19 data found that meeting the integrated 24-hour movement guidelines and different combinations of recommendations within the guidelines was associated with a number of favourable health indicators [7].

  3. Identifying risk profiles for non-adherence to the 24-Hour Movement Guidelines for Children and Youth six months into the COVID-19 pandemic.


    The purposes of the current study were to identify risk profiles for nonadherence among children and youth (5–17 y) at the 6-month mark of the COVID-19 pandemic and to discuss similarities and differences between risk profiles identified in the current study and those identified at the 1-month mark of the pandemic. 

  4. Associations between anxiety disorders and depression symptoms are related to 24-hour movement behaviors among Brazilian adolescents.


    The primary purpose of this study was to compare the effects of adhering to multiple movement-related lifestyle targets on symptom severity of depression in adolescents with a history of anxiety disorders to those with no prior diagnosis of anxiety. A secondary aim was to examine whether treatment status or time since receiving diagnosis of anxiety disorder further moderated any effects of movement behaviors on depression symptom severity.

  5. Body weight at age 4 years and readiness to start school: a prospective cohort study


    Being classified as overweight or with obesity was associated with poor school readiness in year 2 of kindergarten. Early interventions to promote healthy growth before school entry may help promote development and school readiness in young children. (NCT01869530).