Fig. 1

Rest-activity profiles of 24-hour accelerometer data from adolescents in the National Health and Nutrition Examination Survey (2011–2014). Each panel depicts the mean 24-hour activity patterns for participants with high (solid line) and low (dotted) eigenvalues of the first four components derived from the functional principal component analysis (PCA): (A) The first component (42.8% variance), with higher eigenvalues representing a higher amplitude; (B) the second component (24.4% variance), with higher eigenvalues representing earlier activity window; (C) the third component (8.3% variance), with higher eigenvalues representing earlier peak of daytime activity; (D) the forth component (7.1% variance), with higher eigenvalues representing prolonged activity/reduced rest window