Keith Diaz, PhD

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Keith Diaz, PhD is a certified exercise physiologist and Assistant Professor of Behavioral Medicine at Columbia University Medical Center. He is Director of the Exercise Testing Laboratory at the Center for Behavioral Cardiovascular Health. He conducts laboratory- and observational-based research to elucidate the role of prolonged sedentary behavior in the pathogenesis of cardiovascular disease, with a specific focus of iteratively optimizing feasible, sustainable, and cost-effective guidelines for reducing prolonged sitting. He currently serves as PI for several federally funded research studies. His work on sedentary behavior has been featured by theNew York Times,CNN,CBS News,NPR, andthe Guardian, among many others. He also is an expert in physical activity monitoring and has conducted several studies evaluating the accuracy of consumer-based activity trackers such as those made by Fitbit. He regularly serves as an expert witness in criminal cases involving physical activity trackers.

Dr. Diaz also devotes his professional efforts toward individuals with intellectual and developmental disabilities. He is the founder and Co-Director of Project PossABILITY, a disability hiring program at Columbia University Medical Center. He also serves on the Advisory Board for the Center for Dignity in Healthcare for People with Disabilities.

Academic Appointments

  • Florence Irving Associate Professor of Behavioral Medicine (in Medicine)

Administrative Titles

  • Director, Exercise Testing Laboratory at the Center for Behavioral Cardiovascular Health
  • Co-Director, Project PossABILITY

Credentials & Experience

Education & Training

  • BS, 2006 Exercise Physiology, William Paterson University
  • PhD, 2012 Integrative Exercise Physiology, Temple University

Honors & Awards

2018 - New Investigator Award of the American College of Sports Medicine


Research Interests

  • Elucidation of the optimal intervention for breaking up prolonged bouts of sitting
  • Pathophysiological mechanisms by which prolonged sitting is linked to cardiovascular disease
  • Use of accelerometers to objectively measure physical activity and sedentary behaviors

Selected Publications

  1. Gilchrist SC, Howard VJ, Akinyemiju T, Judd SE, Cushman M, Hooker SP, Diaz KM. Sedentary Behavior and Cancer Mortality in Middle-Aged and Older U.S. Adults: the REGARDS Study. JAMA Oncol. 2020; 6(8):1210-1217. PMID: 32556069
  2. Garcia J, Duran AT, Schwartz JE, Booth JN, Hooker SP, Willey JZ, Cheung YK, Park C, Williams SK, Sims M, Shimbo D, Diaz KM. Types of Sedentary Behavior and Risk of Cardiovascular Events and Mortality in African-Americans: The Jackson Heart Study.J Am Heart Assoc. 2019;8:e010406.PMID: 31238767
  3. Diaz KM, Thanataveerat A, Parsons FE, Yoon S, Cheung YK, Alcantara C, Duran AT, Ensari I, Krupka DJ, Schwartz JE, Burg MM, Davidson KW. The Influence of Daily Stress on Sedentary Behavior: Group and Person (N of 1) Level Results of a 1-Year Observational Study. Psychosom Med. 2018;80(7):620-627.PMID: 29846309
  4. Diaz KM, Howard V, Hutto B, Colabianchi N, Vena JE, Safford MM, Blair SN, Hooker SP. Patterns of sedentary behavior and mortality in U.S. middle-aged and older adults: A national cohort study.Ann Intern Med. 2017;167(7):465-475.PMCID: PMC5961729
  5. Diaz KM, Goldsmith J, Greenlee H, Strizich G, Qi Q, Mossavar-Rahmani Y, Vidot DC, Buelna C, Brintz CE, Elfassy T, Gallo LC, Daviglus ML, Sotres-Alvarez D, Kaplan R. Prolonged, uninterrupted sedentary behavior and glycemic biomarkers among US Hispanic/Latino adults: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL).Circulation. 2017;136(15):1362-1373.PMCID: PMC5634934
  6. Diaz KM, Krupka DJ, Chang MJ, Peacock J, Ma Y, Goldsmith J, Schwartz JE, Davidson KW. Fitbit: An accurate and reliable device for wireless physical activity tracking.Int J Cardiol. 2015;185:138-140.PMCID: PMC4406840