Summary: Acute exercise in older adults has a positive impact on brain regions associated with memory and recall. Older adults who engaged in acute exercise had greater activation in the temporal gyrus, fusiform gyrus and hippocampus, resulting in increased semantic memory activation.
Source: University of Maryland
How quickly do we experience the benefits of exercise? A new University of Maryland study of healthy older adults shows that just one session of exercise increased activation in the brain circuits associated with memory – including the hippocampus – which shrinks with age and is the brain region attacked first in Alzheimer’s disease.
“While it has been shown that regular exercise can increase the volume of the hippocampus, our study provides new information that acute exercise has the ability to impact this important brain region,” said Dr. J. Carson Smith, an associate professor of kinesiology in the University of Maryland School of Public Health and the study’s lead author.
The study is published in the Journal of the International Neuropsychological Society.
Dr. Smith’s research team measured the brain activity (using fMRI) of healthy participants ages 55-85 who were asked to perform a memory task that involves identifying famous names and non famous ones. The action of remembering famous names activates a neural network related to semantic memory, which is known to deteriorate over time with memory loss.
This test was conducted 30 minutes after a session of moderately intense exercise (70% of max effort) on an exercise bike and on a separate day after a period of rest. Participants’ brain activation while correctly remembering names was significantly greater in four brain cortical regions (including the middle frontal gyrus, inferior temporal gryus, middle temporal gyrus, and fusiform gyrus) after exercise compared to after rest. The increased activation of the hippocampus was also seen on both sides of the brain.
“Just like a muscle adapts to repeated use, single sessions of exercise may flex cognitive neural networks in ways that promote adaptations over time and lend to increased network integrity and function and allow more efficient access to memories,” Dr. Smith explained.
Dr. Smith’s Exercise for Brain Health Laboratory has ongoing NIH-National Institute of Aging-funded research investigating the influence and benefits of a six month exercise program on the brain and cognitive function in healthy older adults at increased risk for Alzheimer’s disease. His previous research studies provide a variety of evidence that exercise offers protection against age-related decline, including one that showed that adults at increased risk for Alzheimer’s disease who engaged in moderate physical activity over time maintained the volume of their hippocampus compared to those who didn’t exercise.
University of Maryland
Kelly Blake – University of Maryland
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Original Research: Closed access.
“Semantic Memory Activation After Acute Exercise in Healthy Older Adults”
Junyeon Won, Alfonso J. Alfini, Lauren R. Weiss, Corey S. Michelson, Daniel D. Callow, Sushant M. Ranadive, Rodolphe J. Gentili, J. Carson Smith. Journal of the International Neuropsychological Society. doi:10.1017/S1355617719000171
Semantic Memory Activation After Acute Exercise in Healthy Older Adults
Objectives: A growing body of research suggests that regular participation in long-term exercise is associated with enhanced cognitive function. However, less is known about the beneficial effects of acute exercise on semantic memory. This study investigated brain activation during a semantic memory task after a single session of exercise in healthy older adults using functional magnetic resonance imaging (fMRI).
Methods: Using a within-subjects counterbalanced design, 26 participants (ages, 55–85 years) underwent two experimental visits on separate days. During each visit, participants engaged in 30 min of rest or stationary cycling exercise immediately before performing a Famous and Non-Famous name discrimination task during fMRI scanning.
Results: Acute exercise was associated with significantly greater semantic memory activation (Famous>Non-Famous) in the middle frontal, inferior temporal, middle temporal, and fusiform gyri. A planned comparison additionally showed significantly greater activation in the bilateral hippocampus after exercise compared to rest. These effects were confined to correct trials, and as expected, there were no differences between conditions in response time or accuracy.
Conclusions: Greater brain activation following a single session of exercise suggests that exercise may increase neural processes underlying semantic memory activation in healthy older adults. These effects were localized to the known semantic memory network, and thus do not appear to reflect a general or widespread increase in brain blood flow. Coupled with our prior exercise training effects on semantic memory-related activation, these data suggest the acute increase in neural activation after exercise may provide a stimulus for adaptation over repeated exercise sessions.