As people age, brain function slowly declines. Aside from improving physical fitness and overall health, exercise may also help improve brain function in older adults, researchers report. In a study published in the journal Frontiers in Aging Neuroscience, researchers evaluated brain function by performing magnetic resonance imaging (MRI) scans on 70 sedentary (but otherwise healthy) adults who were 60-80 years old. The participants were randomly divided into an aerobic walking group or a non-aerobic control group, which performed toning, stretching and strengthening exercises. Each exercise session lasted 40 minutes and was performed three times weekly for one year. The MRI scans of the older individuals were again taken after six months and one year, and compared to MRI scans of 32 healthy younger individuals (age 18-35). No beneficial effects were observed in the aerobic group after six months of exercise. However, after one year, several improvements in brain function were noted in the aerobic exercise group. Earlier studies suggested that impaired function in a brain circuit called the default mode network (DMN) may be a sign of aging or neurological conditions, such as Alzheimer's. The DMN is active when a person is at a state of wakeful rest, such as daydreaming. In the present study, researchers found that DMN activity significantly improved in the aerobics group compared to the control group. The subjects in the aerobic group also experienced significant improvements in another brain network, the frontal parietal network, which is important for complex tasks. By the end of the study, participants in the aerobics group experienced significant improvements in cognition, including memory and attention, compared to the control group. While the results are promising, additional research is warranted in this area. Reference: Michelle W. Voss, Ruchika S. Prakash, Kirk I. Erickson, Chandramallika Basak, Laura Chaddock, Jennifer S. Kim, Heloisa Alves, Susie Heo, Amanda N. Szabo, Siobhan M. White, Thomas R. Wojcicki, Emily L. Mailey, Neha Gothe, Erin A. Olson, Edward McAuley and Arthur F. Kramer, "Plasticity of brain networks in a randomized intervention trial of exercise training in older adults." Frontiers in Aging Neuroscience 2010. 2:32.