Evidence for the benefits of regular physical activity for several major health diseases is clear and unanimous. Current public health guidelines are promoting at least 150 minutes per week of moderate to vigorousintensity leisure-time physical activity.

Recent, observational studies have suggested that prolonged bouts of sitting time and lack of whole-body muscular movement are strongly associated with obesity, abnormal glucose metabolism, diabetes, metabolic syndrome, cardiovascular disease (CVD) risk and cancer, as well as total mortality independent of moderate to vigorous-intensity physical activity.1,–,5 Accordingly, a possible new paradigm of inactivity physiology is suggested, separate from the established exercise physiology, that is, molecular and physiological responses to exercise.6 This new way of thinking emphasises the distinction between the health consequences of sedentary behaviour, that is, limiting everyday life non-exercise activity and that of not exercising. Until now, the expression “sedentary behaviour” has misleadingly been used as a synonym for not exercising. Sedentary time should be defined as the muscular inactivity rather than the absence of exercise.

The new proposed paradigm of inactivity physiology is based …