Centralized myofiber nuclei increased with age and following tongue exercise. A Schematic of tissue cross section. B, C Percentage of centralized nuclei increased in the old group in GG (F1,20 = 7.204, p = 0.014) and SG (F1,20 = 8.178, p = 0.001). D Following 17 days of exercise, percentage of centralized nuclei increased in GG (p = 0.033). F Representative images from the GG of a young adult and old rat. (*p-value < 0.05; sample size indicated in individual bar-plots.)