American College of Sports Medicine 2015 Annual Meeting
San Diego, CA, USA
May 27, 2015
Sapphire M Hotel


Considerable recent attention has been generated around the role that sedentary behavior may play in health outcomes. Although a clear consensus definition of sedentary behavior has been elusive, the term generally refers to behaviors that are performed at or below a light intensity. Examples of sedentary behavior include many activities done while sitting or reclining, such as watching TV, reading, using a computer, as well as sleeping. Early studies have suggested that people who spend more time in sedentary behaviors are at a higher risk of all-cause mortality and certain non-communicable disease outcomes than similar peers with less sedentary time. Moreover, these observations hold even when controlling for current vigorous or moderate intensity physical activity, suggesting that there may be some independence of sedentary behavior and physical activity behavior.

Though these observations are intriguing, very little information exists regarding the potential physiologic mechanisms through which sedentary behavior increases risk of disease, particularly if it is independent of physical activity behaviors. The general physiologic principles of overload, specificity and adaptation, are thought to drive the understanding of the role that physical activity plays in disease processes, but it is not apparent how these principles apply to sedentary behavior. Without such physiologic information, it becomes difficult to explain the observational results. There exists a need to understand physiologic mechanisms of sedentary behavior in determining health risks. This session will include the presentation of a conceptual framework on sedentary behavior, physical inactivity and health that will advance efforts to better elucidate the physiological mechanisms related to sedentary behavior.


Introduction and Welcome
Co-Chairs: William Haskell, PhD, Stanford University & Bill Kohl, PhD, University of Texas School of Public Health

Behavioral Aspects of Physical Inactivity and Sedentary Behavior Versus Physical Activity 
David Dunstan, PhD, Baker IDI Heart and Diabetes Institute

Physiological Aspects of Physical Inactivity and Sedentary Behavior Versus Physical Activity
Benjamin D. Levine, MD, University of Texas Southwestern Medical Center

Public Health Guidelines for Sedentary Behavior 
Mark Tremblay, PhD, University of Ottawa

Conceptual Framework on Sedentary Behavior, Physical Inactivity, & Health
Bill Kohl, PhD, University of Texas School of Public Health

Short Panel Discussion
Moderated by Dr. Haskell

This session was sponsored by the IAFNS Energy Balance & Active Lifestyle Committee.