Physical inactivity is becoming an important component of the physical activity and health equation. Sedentary behavior refers to any waking activity characterized by an energy expenditure ≥ 1.5 METS and a sitting or reclining posture (1). Time spent in sedentary behavior is distinct from lack of physical activity as these are considered unique behavioral constructs that have independent relationships to various health outcomes.(2) New evidence suggests that prolonged, unbroken sitting time is related to increased risk of obesity, type 2 diabetes, and cardiovascular disease.
In public health recommendations, physical inactivity is often used to refer to a broader pattern of behavior that is marked by low levels of physical activity and/or has an excess of time spent sitting, or sedentary. In epidemiological research, the term “ physical inactivity” refers to a state in which body movement is minimized.(3) This would include sleeping, as well as, activities performed during waking hours that result in lower levels of energy expenditure. Physical inactivity that takes place during waking hours is typically referred to as sedentary behavior.(4) Understanding the roles of both physical activity and sedentary behavior in disease pathways requires methods that can accurately report low intensity activities in addition to moderate and high intensity activities. Therefore, intensity of activity can have important implications on which method of assessment is the most appropriate for a given research design. In general, measurement methods that do not adequately capture information on frequency, duration, and intensity will result in less precise or inaccurate assessments of both physical activity and sedentary behavior.
Examples of Sedentary Behaviors:
- Sitting Time
- TV viewing
- Playing video games
- Computer use
- Commuting (Driving or Passenger)
Similar to physical activity, sedentary behavior may be assessed using self-report measures. Self-report methods of sedentary behavior often focus on TV viewing, screen time (computer or video game use), and overall sitting time. Below are some commonly used self-report tools used to assess sedentary behaviors:
- HELENA Sedentary Behaviors Questionnaire – (Rey-Lopez, 2011)
- Sedentary Behavior Questionnaire (SBQ) – reports on time spent in 9 sedentary behaviors (Rosenberg, 2010)
- Self-Administered Physical Activity Checklist (SAPAC) - this tool has been psychometrically tested and uses a long list of prompts (Brown et al, 2004)
- Previous Day Physical Activity Recall (PDPAR) - designed to assess physical activity and sedentary behaviors (Pate et al, 1997; Pate et al 1999)
- Multimedia Activity Recall for Children and Adolescents (MARCA) - a computerized 24-hour activity recall linked to a compendium of energy expenditure (Ridley et al, 2002)
- Adolescent Sedentary Activity Questionnaire (ASAQ) - includes five categories: small screen recreation, education, travel, cultural activities and social activities (Hardy et al, 2007)
- Sedentary Behaviour Research Network. 2012. Standardized use of the terms “sedentary” and “sedentary behaviours”. Appl Physiol Nutr Metab. 37: 540–542.
- Dunstan DW, Barr EL, Healy GN, Salmon J, Shaw JE, Balkau B et al. Television viewing time and mortality: the Australian Diabetes, Obesity and Lifestyle Study (AusDiab). Circulation 2010; 26: 384–391.
- Dietz WH. The role of lifestyle in health: the epidemiology and consequences of inactivity. Proc Nutr Soc. 1996;55(3):829-40.>
- Owen N, Healy GN, Matthews CE, and Dunstan DW. Too much sitting: the population health science of sedentary behavior. Exerc Sport Sci Rev. 2010;38(3):105-13.