Figure 2.

Diurnal differences in muscle force. Maximum voluntary isometric contraction (MVIC) force (A) and peak rate of force development; (B) of the quadriceps femoris muscle in the morning (08:00 h) and evening (18:00 h). Shaded (gray) data points represent data from n = 10 participants that gave muscle biopsy samples, whereas open (white) data points represent data from n = 10 participants that did not undergo biopsy procedures. Within-subject data are connected by dashed lines and group data (median, quartile ranges) are summarized by ‘box and whisker’ plots. Statistical differences were assessed by Student’s paired t-test, n = 20.