Abstract

Objective methods are being used increasingly for the quantification of amount of physical activity, intensity of physical activity, and amount of sedentary behaviour in children. The accelerometer is currently the objective method of choice.

In this review we address the advantages of objective measurement over more traditional subjective methods, notably the avoidance of bias, greater confidence in the amount of activity and sedentary behaviour measured, and improved ability to relate variation in physical activity and sedentary behaviour to variation in health outcomes. We also consider unresolved practical issues in paediatric accelerometry by critical review of existing evidence and by providing new evidence.