Kirk I. Erickson at the University of Illinois did a study of 299 dementia-free people who recorded the number of blocks they walked weekly. Brain scans were taken nine years later and after four more years they were tested to see if they had developed cognitive impairment or dementia. Erickson began the work while at Illinois as a post-doctoral student and completed it as an assistant professor at the University of Pittsburgh. They found that those who walked seventy-two blocks per week, equivalent to six to nine miles, had greater brain volume that those who walked less.
Erickson said, “Brain size shrinks in late adulthood, which can cause memory problems. These results should encourage well-designed trials of physical exercise in older adults as a promising approach for preventing dementia and Alzheimer’s disease.” The study was published in the journal Neurology.
Even Couch Potatoes Can Benefit
A study conducted at the University of Illinois by Art Kramer, Edward McAuley and Michelle Voss followed sixty-five adults aged fifty-nine to eighty who joined a walking group or a stretching and toning group for a year. The walkers moved at an aerobic pace, approximately seventy percent of their MHR (maximum heart rate).
At year’s end the walkers had significant improvement in DMN (default mode network). DMN dominates activity when a person is least engaged with the outside world — just observing or daydreaming or thinking — that’s using their brain during passive activity times. Better DMN means better performance at tasks like planning, prioritizing and multi-tasking.
They also had increased connectivity in parts of the brain related to performing complex tasks and did better on cognitive tests. The stretching and toning group did not do nearly as well.
All of the evidence points to aerobic exercise providing the keys to the brain kingdom. This study seems to show that even while a little is good, more is better. To retain the benefits, you have to keep it up. This is not a case of “I’ve done that, now I can go back to my old habits.”