Past research has linked aerobic exercise with slower cognitive decline in Alzheimer’s patients. This may be related to the fact that exercise has been found to improve connectivity between neurons in older adults. A new study adds more evidence to this link and may provide more insight into why exercise is beneficial.
Recent research from the University of Maryland School of Public Health examined the brains and story recall of older adults on a treadmill-based exercise regiment. The research, published in the Journal of Alzheimer’s Disease Reports, aimed to understand how these workouts impacted brain network connectivity.
J. Carson Smith, principal investigator and kinesiology professor at the School of Public Health, explains, “Historically, the brain networks we studied in this research show deterioration over time in people with mild cognitive impairment and Alzheimer’s disease. They become disconnected, and as a result, people lose their ability to think clearly and remember things. We’re demonstrating that exercise training strengthens these connections.”
Smith has been studying the topic for a while, with prior research indicating that walking may decrease cerebral blood flow and improve brain function in those with mild cognitive impairment.
For the current study, 33 older adults with either normal cognitive health or mild cognitive impairment were recruited. The participants ranged in age from 71 to 85. They all did supervised treadmill walks four times a week for 12 weeks, and before beginning this routine, were asked to read a short story and repeat it out loud with as much detail as they could remember. After the 12-week exercise period wrapped, they were asked to do it again.
In addition to this, they underwent MRIs so researchers could look at three brain networks related to cognitive function: the default mode network, which is active when a person isn’t engaged in anything; the frontoparietal network, which regulates decisions made when a person completes a task; and the salience network, which keeps track of various stimuli a person encounters and decides what to focus on.
After 12 weeks, the participants were found to have significantly better story recall, as well as stronger activity in the default mode network, the salience network, and in the connections between all three networks studied.
Smith says, “The brain activity was stronger and more synchronized, demonstrating exercise actually can induce the brain’s ability to change and adapt. These results provide even more hope that exercise may be useful as a way to prevent or help stabilize people with mild cognitive impairment and maybe, over the long term, delay their conversion to Alzheimer’s dementia.”
How much physical activity should you be doing each week as an older adult? The U.S. Centers for Disease Control and Prevention recommends at least 150 minutes per week of moderate-intensity activity, which includes brisk walking. At least two days a week of strength workouts are recommended, as well.