Walking enhances connections within and between three brain networks, including one associated with Alzheimer’s disease, according to a new study from the University of Maryland School of Public Health, adding to the growing body of evidence that exercise benefits brain health.
The study, which was published this month in the Journal of Alzheimer’s Disease Reports, looked at the brains and story recollection abilities of older adults with normal brain function and those with mild cognitive impairment, which is a slight decline in mental abilities such as memory, reasoning, and judgement and a risk factor for Alzheimer’s.
J. Carson Smith, a professor of kinesiology at the School of Public Health and the study’s primary investigator, said that previous research has shown that the brain networks we looked at in this research deteriorate with time in patients with moderate cognitive impairment and Alzheimer’s disease. “They become disconnected, and people lose their ability to think clearly and remember things as a result.” We show that exercise training improves these linkages.”
Smith’s prior research indicated that walking can reduce cerebral blood flow and enhance brain function in older persons with moderate cognitive impairment.
Thirty-three volunteers, aged 71 to 85, walked on a treadmill four days a week for 12 weeks while being observed.
Researchers asked participants to read a short tale and then repeat it out loud with as many details as possible before and after this workout routine.
Participants also had functional magnetic resonance imaging (fMRI) to detect changes in communication within and across the three brain networks that affect cognitive function:
Default mode network – This network is activated when a person is not performing a specific activity (for example, thinking about the grocery list) and is linked to the hippocampus, which is one of the first brain areas impacted by Alzheimer’s disease. It’s also where Alzheimer’s and amyloid plaques, which are formed surrounding nerve cells and are a leading candidate for Alzheimer’s disease, show up in testing.
Frontoparietal network – Controls judgements made while completing a job. It also requires memory.
Salience network – Monitors the outside environment and stimuli before deciding what warrants attention. It also makes switching between networks easier in order to optimise performance.
Researchers repeated the tests after 12 weeks of exercise and found substantial increases in individuals’ tale recall ability.
“The brain activity was stronger and more synchronised, demonstrating that exercise can actually induce the brain’s ability to change and adapt,” Smith explained. “These findings give us even more hope that exercise can help prevent or stabilise people with mild cognitive impairment and, in the long run, delay their progression to Alzheimer’s dementia.”
