Walking at one’s own pace for 40 minutes three times a week can enhance the connectivity of important brain circuits, combat declines in brain function associated with aging, and increase performance on cognitive tasks, researchers have found.

The new study used fMRI to determine whether aerobic activity increased connectivity in the default mode network (DMN), which dominates brain activity when a person is least engaged with the outside world, and in the fronto-executive network, which aids in the performance of complex tasks. Previous studies found that a loss of coordination in the DMN is a common symptom of aging and in extreme cases can be a marker of disease.

“Almost nothing in the brain gets done by one area — it’s more of a circuit,” said University of Illinois psychology professor and Beckman Institute Director Art Kramer, who led the study with kinesiology and community health professor Edward McAuley and doctoral student Michelle Voss. “These networks can become more or less connected. In general, as we get older, they become less connected, so we were interested in the effects of fitness on connectivity of brain networks that show the most dysfunction with age.”

The study, in Frontiers in Aging Neuroscience, followed 65 adults, aged 59 to 80, who joined a walking group or stretching and toning group for a year. All of the participants were sedentary before the study, reporting less than two episodes of physical activity lasting 30 minutes or more in the previous six months. The researchers also measured brain activity in 32 younger (18- to 35-year-old) adults.

The paper, “Plasticity of Brain Networks in a Randomized Intervention Trial of Exercise Training in Older Adults,” is available online.

More info: University of Illinois news