Fig. 1
Quantitative metrics of 24-h activity patterns. Left, cosinor variables are calculated by fitting a cosine function to the accelerometer data. Mesor (midline-estimating statistic of rhythm) is the mean activity level of the cosine wave. Amplitude is defined as the distance between the mean activity level and the peak of the cosine wave. Right, nonparametric variables do not require fitting a shape to the accelerometer data. Interdaily stability is defined as the regularity of the 24-h rhythm across days, whereas intradaily variability represents the fragmentation of activity within the average 24-h day. L5 (least active 5 h) represents the mean activity level during what is typically time in bed, and M10 (most active 10 h) represents mean activity level during the day