The human brain is organized into separable functional networks during rest and varied states of cognition and as we get older, these become less connected. Low connectivity means that the different parts of the circuit are not operating in sync. Like poorly trained athletes on a rowing team, the brain regions that make up the circuit lack coordination and so do not function at optimal efficiency or speed.
Now, a group of ageing "professional couch potatoes" has proven that even moderate exercise -- in this case 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 lead by Art Kramer of the University of Illinois 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.
Results showed that aerobic training improved the aging brain’s resting functional efficiency in higher-level cognitive networks. One year of walking increased functional connectivity between aspects of the frontal, posterior, and temporal cortices within the Default Mode Network (DMN), and a Frontal Executive Network, two brain networks central to brain dysfunction in aging.
Previous research has shown that older adults who are more fit tend to have better connectivity in specific regions of the DMN than their sedentary peers. The higher the connectivity, the better the performance on some of these cognitive tasks, especially the ones we call executive control tasks -- things like planning, scheduling, dealing with ambiguity, working memory and multitasking, the very skills that tend to decline with aging.
Although age is a prominent risk factor for Alzheimer's disease (AD), epidemiological studies have shown that lifestyle factors such as physical exercise significantly decrease age-related risks for cognitive impairment and AD
Couch Potatoes, start walking now or end up walking to nowhere as you age!
Michelle W. Voss, Ruchika S. Prakash, Kirk I. Erickson, Chandramallika Basak, Laura Chaddock, Jennifer S. Kim, Heloisa Alves, Susie Heo, Amanda Szabo, Siobhan M. White, Thomas R. Wojcicki, Emily L. Mailey, Neha Gothe, Erin A. Olson, Edward McAuley, Arthur F. Kramer. Plasticity of Brain Networks in a Randomized Intervention Trial of Exercise Training in Older Adults. Frontiers in Aging Neuroscience, 2010 August; 2(32):1-17 Picture Credit