Summary: A single session of moderate exercise in healthy older adults increases activity in brain regions tied to memory and recall. Participants who exercised showed stronger activation in the temporal gyrus, fusiform gyrus and hippocampus, indicating enhanced semantic memory engagement shortly after exercise.
Source: University of Maryland
One Workout, Noticeable Changes: Acute Exercise Boosts Memory-Related Brain Activity in Older Adults
How quickly do the cognitive benefits of exercise appear? New research from the University of Maryland shows that a single bout of moderate-intensity exercise can measurably increase activation in key memory networks of the aging brain, including the hippocampus — a structure that typically shrinks with age and is among the first affected in Alzheimer’s disease.
“Although long-term exercise is known to increase hippocampal volume, our findings show that even one session of exercise can influence this critical brain region,” said Dr. J. Carson Smith, associate professor of kinesiology in the University of Maryland School of Public Health and lead author on the study.
The peer-reviewed study appears in the Journal of the International Neuropsychological Society.
Study design and participants
Researchers used functional magnetic resonance imaging (fMRI) to measure brain activity in 26 healthy adults aged 55–85. In a within-subjects, counterbalanced design, each participant completed two separate visits. On one visit they performed 30 minutes of stationary cycling at approximately 70% of maximal effort; on the other visit they rested for 30 minutes. Roughly 30 minutes after each condition, participants performed a semantic memory task while undergoing fMRI scanning.
The task required discriminating famous names from non-famous names. Correctly recognizing famous names reliably recruits a semantic memory network, allowing the team to test whether a single exercise session would alter the neural responses supporting that type of memory.
Key findings
After the exercise session, brain activation for correctly identified famous names (compared with non-famous names) was significantly greater in several cortical regions associated with semantic memory processing. These areas included the middle frontal gyrus, inferior temporal gyrus, middle temporal gyrus, and fusiform gyrus. In addition, planned comparisons revealed increased activation in the hippocampus on both sides of the brain following exercise versus rest.
Notably, the exercise-related increases were specific to correct trials of the memory task; there were no differences between exercise and rest in overall response time or accuracy. This pattern suggests that acute exercise enhances neural engagement within the semantic memory network rather than producing a general, nonspecific rise in brain activity or blood flow.
Interpretation and implications
Dr. Smith explained that, analogous to how a muscle responds to exercise, single sessions of aerobic activity may transiently “flex” cognitive neural networks. Repeated exposure to these transient increases in activation could provide the stimulus for long-term adaptation, improving network integrity and making memory retrieval more efficient over time.
These results complement prior work from Dr. Smith’s Exercise for Brain Health Laboratory, including longitudinal studies showing that sustained moderate physical activity helps preserve hippocampal volume in older adults at increased risk for Alzheimer’s disease. Together, the acute and training studies suggest both immediate and cumulative pathways by which exercise supports brain health during aging.
Source:
University of Maryland
Media Contacts:
Kelly Blake – University of Maryland
Image Source:
The image is in the public domain.
Study citation and abstract summary
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
Abstract (summary): The study tested whether a single session of exercise affects semantic memory activation in older adults. Using a within-subjects counterbalanced design, 26 participants (ages 55–85) completed two visits that included either 30 minutes of rest or 30 minutes of stationary cycling followed by fMRI during a famous/non-famous name discrimination task. Acute exercise produced significantly greater activation for the famous>non-famous contrast in the middle frontal, inferior temporal, middle temporal, and fusiform gyri, and also increased bilateral hippocampal activation. Effects were confined to correct trials, with no condition differences in response time or accuracy. The findings indicate that one bout of aerobic exercise can amplify neural processes supporting semantic memory in healthy older adults and may act as a stimulus for adaptation across repeated exercise sessions.