Too much sitting: the population health science of sedentary behavior

Abstract

Even when adults meet physical activity guidelines, sitting for prolonged periods can compromise metabolic health. Television (TV) time and objective measurement studies show deleterious associations, and breaking up sedentary time is beneficial. Sitting time, TV time, and time sitting in automobiles increase premature mortality risk. Further evidence from prospective studies, intervention trials, and population-based behavioral studies is required.

Figure 1

Being physically active, but also highly sedentary: one week of accelerometer-count data showing, on average, 31 mins/day moderate-to-vigorous activity time (> 1951 counts/min) and 71% of waking hours sedentary (< 100 counts/min).

Figure 2

Breaks in sedentary time: same amount of sedentary time, but different ways of accumulation. CPM = counts per minute. (Reprinted from Dunstan DW, Healy GM, Sugiyama T, Owen N. ‘Too Much Sitting’ and Metabolic Risk – has modern technology caught up with us? US Endocrinology. 2009;5(1), 29-33. Copyright © 2009 Touch Briefings. Used with permission.)

Figure 3

Associations of breaks in sedentary time with waist circumference (based on data from Healy et al. (21)).

Figure 4

Behavioral epidemiology framework: phases of evidence for a population-health science of sedentary behaviour.