tudy. Highly detailed analysis of local peaks in the signal might be needed, for instance to reveal an association between activity and reported events. But analyses can also be more global, for instance when accelerometer data are used to study circadian rhythms in activity. Several approaches exist to combine the X, Y, Z measurements into a single meaningful metric. Two popular metrics are the ‘Signal Vector Magnitude’ (SVM) and the ‘Euclidean Norm Minus One’ (ENMO). Validation studies suggest tha