Assistant professor of psychiatry at Boston University School of Medicine, Scott Hayes, PhD, and his research team, were prompted to do research on cardiac fitness and brain health in older adults after serveral animal studies that showed physical activity positively impacting memory performance and brain regions critical for memory.

"There was no human work demonstrating associations between fitness, memory and the brain—so our study was developed to address that gap in the literature," said Hayes. "Furthermore, VA Boston had recently opened new exercise facility for cardiac rehabilitation, which along with our 3 Tesla ­­MRI scanner, really facilitated data collection."

The study published in Cortex, assessed the cardiorespiratory fitness of 26 older (55 to 74 years old) and 31 young adults (18 to 31 years old), as they jogged on a treadmill. The researchers collected functional MRI data while participants learned face-name associations. 

"Among older adults, we saw a positive association between cardiorespiratory fitness and fMRI activation during face-name learning in multiple brain regions important for memory, including the thalamus, hippocampus, and prefrontal cortex," said Hayes. "Further, activation in these regions was also correlated with memory performance among older adults. Finally, when we compared fMRI activation in high and low fit older adults to younger adults, we saw that fMRI activation in high fit older adults was more similar to young adults in more posterior brain regions, suggesting cardiorespiratory fitness may keep the brain more youthful. In prefrontal cortex, high fit older adults showed increased activation to low fit older adults and young adults, suggesting it may also contribute to neural compensation, that is, the recruitment of additional brain regions to complete the memory task at hand."

Hayes is hoping that this additional information will also play a part in motivating people to exercise. 

"Most people know that exercise can positively impact musculoskeletal and cardiovascular health, yet many people remain sedentary. Maybe showing that physical fitness is also associated with brain health and memory will provide some additional motivation to be physical active and get fit. Exercise alone is unlikely to eliminate age-related neural and cognitive decline, but it could help attenuate age-related neurodegeneration."