Figure 2. The exercise-induced phase shift of the skeletal muscle clock.
Exercise can induce a phase shift in the skeletal muscle clock in response to the timing of exercise shown here as a representative effect of either Early Active (AM) or Late Active (PM) phase exercise (Ex; dashed vertical lines). Shifts in the muscle clock phase (dashed curve) are identified through Period 2 (Per2) of the muscle clock’s negative arm, from its rhythm prior to exercise (solid curve). Arrows indicate the direction of the phase shift.