Regular physical activity has long been linked to a variety of health benefits, including better brain function and cognitive abilities. Walking, a type of aerobic exercise, appears to improve brain connectivity and memory, particularly in older adults.
According to new research, regular walks strengthen connections in and between brain networks, adding to the growing body of evidence linking exercise to a slower onset of Alzheimer’s disease. The study looked at the brains and memory 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 judgment and a risk factor for Alzheimer’s.
A new University of Maryland School of Public Health study reveals how walking strengthens connections within and between three of the brain’s networks, including one associated with Alzheimer’s disease, adding to the growing evidence that exercise improves brain health.
The brain activity was stronger and more synchronized, demonstrating that exercise can actually induce the brain’s ability to change and adapt. These findings give us even more hope that exercise can help prevent or stabilize people with mild cognitive impairment and, in the long run, delay their progression to Alzheimer’s dementia.
J. Carson Smith
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 judgment and a risk factor for Alzheimer’s.
“Historically, the brain networks we studied in this research show deterioration over time in people with mild cognitive impairment and Alzheimer’s disease,” said J. Carson Smith, the study’s principal investigator and a kinesiology professor at the School of Public Health. “They become disconnected, and people lose their ability to think clearly and remember things as a result.” We show that exercise training strengthens these connections.”
The study builds upon Smith’s previous research, which showed how walking may decrease cerebral blood flow and improve brain function in older adults with mild cognitive impairment.
Thirty-three participants, aged 71 to 85, walked on a treadmill four days a week for 12 weeks while being supervised. Researchers asked participants to read a short story and then repeat it out loud with as many details as possible before and after this exercise regimen.
Participants also underwent functional magnetic resonance imaging (fMRI) so researchers could measure changes in communication within and between the three brain networks that control cognitive function:
- Default mode network – Activates when a person isn’t doing a specific task (think daydreaming about the grocery list) and is connected to the hippocampus — one of the first brain regions affected by Alzheimer’s disease. It’s also where Alzheimer’s and amyloid plaques, a prime suspect for Alzheimer’s disease found around nerve cells, show up in tests.
- Frontoparietal network — Regulates decisions made when a person is completing a task. It also involves memory.
- Salience network — Monitors the external world and stimuli and then decides what deserves attention. It also facilitates switching between networks to optimize performance.
Researchers repeated the tests after 12 weeks of exercise and found significant improvements in participants’ story recall abilities.
“The brain activity was stronger and more synchronized, 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 stabilize people with mild cognitive impairment and, in the long run, delay their progression to Alzheimer’s dementia.”
