Fig. 5.

Glycogen and glycogen metabolism were determined after an overnight fast (rest) and after 1 h ergometer cycling at 65% V̇o_{2 peak} (Exercise). Throughout the figure, open bars indicate a noninsulin-stimulated condition and closed bars indicate an insulin-stimulated condition. A: glycogen stores were significantly reduced during exercise (main effect of experimental day = *P < 0.05). B: nonoxidative glucose disposal (NOGD) was increased during insulin stimulation, and exercise tended to increase NOGD (main effect of hyperinsulinemic euglycemic clamp = §P < 0.05, #P < 0.05 vs. basal within experimental day). C: Ser⁶⁴¹ phosphorylation on glycogen synthase (GS) was significantly reduced by both exercise and insulin stimulation, indicating increased GS activity.