COMMENTARYSedentary Behavior: Emerging Evidence for a New Health Risk
Section snippets
New Technology Characterizes Sedentary and Physically Active Time in Populations
Nonexercise behaviors can be differentiated into 2 categories: sedentary behavior, which may be defined as sitting, lying down, and expending very little energy (approximately 1.0-1.5 metabolic equivalents [METs]), and light-intensity activity, such as standing, self-care activities, and slow walking, which require low energy expenditure (approximately 1.6-2.9 METs).10 Advances in microelectronic technologies, specifically the accelerometer, have enabled the time spent in sedentary,
New Insights Into Sedentary Behavior and Cardiometabolic Risk
Recent studies have documented deleterious associations of adults' reported television viewing time and overall sedentary time with central adiposity (larger waist circumference) and with fasting triglyceride levels and markers of insulin resistance (ie, fasting insulin level, 2-hour glucose) that are independent of both central adiposity and exercise time.13, 14, 15, 16, 17 With prolonged periods of sitting, fewer skeletal muscle contractions may result in reduced lipoprotein lipase activity
Conclusion
In recent decades, affluent populations have become increasingly sedentary, with many adults spending 70% or more of their waking hours sitting. Parallel with this change, evidence has emerged identifying habitual sedentary behavior (prolonged sitting) as a novel risk factor for cardiometabolic disease and all-cause mortality, independent of time spent in exercise. As this evidence is primarily observational in nature, further experimental research investigating potential mechanisms and
REFERENCES (28)
- et al.
Sedentary behavior, physical activity, and concentrations of insulin among US adults
Metabolism
(2010) - et al.
An obligation for primary care physicians to prescribe physical activity to sedentary patients to reduce the risk of chronic health conditions
Mayo Clin Proc
(2002) - et al.
Obesity and the environment: where do we go from here?
Science
(2003) - et al.
Declining rates of physical activity in the United States: what are the contributors?
Annu Rev Public Health
(2005) Internet Use in the United States: October 2009. US Census Bureau Web site
Three Screen Report. 1st Quarter 2010. What consumers watch: technology enhances the video experience HDTV, timeshifting, broadband and smartphones contribute to higher levels of video viewing
Summary of travel trends: National Household Travel Survey (NHTS). NHTS Web site. Released December 2004
- et al.
Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association
Circulation
(2007) 2008 physical activity guidelines for Americans
(2008-2009)- et al.
Television viewing time and mortality: the AusDiab study
Circulation
(2010)