When combined with a lack of physical activity, the association was even stronger. Women and men who both sat more and were less physically were 94% and 48% more likely, respectively, to die compared with those who reported sitting the least and being most active.

“Several factors could explain the positive association between time spent sitting and higher all-cause death rates,” said Dr. Patel. “Prolonged time spent sitting, independent of physical activity, has been shown to have important metabolic consequences, and may influence things like triglycerides, high density lipoprotein, cholesterol, fasting plasma glucose, resting blood pressure, and leptin, which are biomarkers of obesity and cardiovascular and other chronic diseases.”