Empirically derived cut-points for sedentary behaviour: are we sitting differently?

摘要

Sedentary behaviour (SB) is associated with a number of adverse health outcomes. Studies that have used ActiGraph monitors to define sedentary time tend to use a threshold of < 100 counts per minute (cpm) for classifying SB; however, this cut-point was not empirically derived for adults. It is not known whether ActiGraph cut-points for SB differ depending on the context in which it occurs. We aimed to: (1) empirically derive an optimal threshold for classifying SB, using the cpm output from the ActiGraph GT3X+, compared to the sedentary classification from the activPAL3 (TM); and (2) ascertain whether this varied by day of the week and in working time versus non-working time.