Too much sitting: a novel and important predictor of chronic disease risk?

• Published in: British journal of sports medicine Vol. 43; no. 2; pp. 81 - 83
• Main Authors: Owen, N, Bauman, A, Brown, W
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine 01.02.2009; BMJ Publishing Group LTD
• Subjects: Adult; Behavior; Cardiovascular disease; Child; Chronic Disease - prevention & control; Chronic illnesses; Diabetes; Exercise; Female; Health Promotion; Humans; Leisure; Male; Metabolism; Obesity; Physical fitness; Population; Public health; Risk Factors; Studies; Weight control; Womens health
• ISSN: 0306-3674; 1473-0480
• DOI: 10.1136/bjsm.2008.055269

In this context, the metabolic equivalent (MET) is used to define body mass neutral energy expenditure of activities, as the ratio of the metabolic rate of the activity and resting metabolic rate, which is defined as 1 MET. 9 Running has a MET value of at least 8 METS, moderate-pace walking has a value of about 3-4 METs and sedentary behaviours are in the range of 1-1.5 METs. 10 11 A recently published prospective study showed that self-reported sitting time (as a marker of sedentary behaviour) was a predictor of weight gain in Australian women, even after adjustment for energy intake and leisure time physical activity. 11 This was followed by observational studies using objective measurement of sedentary time, which showed that not only is total sedentary time important for blood glucose control but also that a larger number of breaks in sedentary time are associated with more favourable metabolic profiles. 4 12 Additionally, these relationships have been found to be consistently stronger for women than for men. 11 12 Recent findings also suggest that leisure time MVPA, in the context of otherwise sedentary lifestyles ( fig 1 ), 4 is unlikely to be sufficient to prevent increasing population levels of overweight, obesity and chronic disease. 3 More than two-thirds of the mid-age population in developed countries like the UK, the USA and Australia is now overweight or obese, which poses additional significant health risks for this generation. 13 Also, about 6% of children are also now obese 14 and this obesity is likely to track into adulthood. 15 Both overweight/obesity and physical inactivity in mid-age are strong markers for the development of non-communicable disease over time. 16 17 Thus, reducing sitting time may have at least as important a role as promoting physical activity in maintaining healthy weight and in preventing further weight gain and improving chronic disease outcomes in mid-age adults; it is crucial for the future health of ageing populations.