Too much sitting and cardio-metabolic risk: an update of epidemiological evidence

Sedentary behavior, as distinct from a lack of moderate-to-vigorous physical activity, is an emerging health risk behavior for the development of chronic diseases. Examples of sedentary behavior include sitting, watching television, using a computer, and driving a car. In this article, we define sedentary behavior; outline key concepts related to the physiology of sedentary behavior, review the recent evidence on the effects of prolonged sedentary behavior (or sitting) on the risk of cardio-metabolic disease and all cause mortality, and discuss the implications for current clinical practice. We found that most large scale studies on sedentary behavior were published in the last 5 years. There is moderately consistent evidence for an association between total sitting time and all-cause mortality, even when adjusted for or stratified by leisure time physical activity. Overall, we identified a compelling case for sitting reduction to be included in clinical preventive advice as a key component of 'active living,' where adults and children are encouraged to 'move more and sit less' across different settings and locations throughout the day.