Figure 1

Number of animals in each young or aged rat groups. NC = normal controls with free access to food; FRC = Food restricted controls that were neither trained nor performed the task; TR = trained-only controls that were food restricted animals that were also trained for four weeks, and then rested for 12 weeks; HRLF = food restricted animals that were trained for four weeks, and then performed the high repetition low force task for 6 and 12 weeks.