EFFECTS OF AGEING ON SITTING BEHAVIOR Losing the ability to stand up may lead to avoidance of moving around, further inactivity and longer sitting. A recent not yet published study involving 884 subjects revealed a significant increase in sitting duration with ageing in the 81- 100 age group compared to the 71-80 age group (Figure 2). 12 Duration of sitting Figure 2. Cross-sectional age differences in sitting duration. Data collected in the Gray Power study of the Vrije Unive