Fitness Influences Memory in Older Adults

A recent study found that physically fit older adults had increased brain and memory function than their unfit peers.

The study included 26 older adults between 55 and 74 years of age and 31 young adults between 18 and 31 years of age who completed a treadmill-based exercise test and face-name associative encoding task. Researchers measured the cardiorespiratory fitness (peak VO₂) during the treadmill test, and measured brain activity using functional magnetic resonance imaging (fMRI) during the face-name associative encoding task.
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In addition, researchers assessed whether cardiorespiratory fitness influenced age-related differences and compared high and low cardiorespiratory fitness in older adults to young adults.

Their results showed that peak VO₂ was positively associated with fMRI activity during the encoding task in multiple regions of the brain in cardiorespiratory fit older adults—including the bilateral prefrontal cortex, medial frontal cortex, bilateral thalamus, and left hippocampus—compared to older adults that were not cardiorespiratory fit.

Likewise, high cardiorespiratory fitness in older adults showed fMRI activation that was similar to young adults in multiple regions of the brain, including the thalamus, posterior, and prefrontal cortex. In the prefrontal cortex, older adults with high cardiorespiratory fitness had more activation than young adults, and low cardiorespiratory fitness older adults. The fMRI activity was positively associated with source memory in older adults.

Overall, the results demonstrated that associative encoding activation in the medial frontal cortex is indirectly influenced by the relationship between peak VO₂ and source memory performance.

“These results indicate that [cardiorespiratory fitness] may contribute to neuroplasticity among older adults, reducing age-related differences in some brain regions, consistent with the brain maintenance hypothesis, but accentuating age-differences in other regions, consistent with the brain compensation hypothesis,” the researchers concluded.

—Melissa Weiss

Reference:

Hayes SM, Hayes JP, Williams VJ, Liu Huiting, and Verfaellie M. FMRI activity during associative encoding is correlated with cardiorespiratory fitness and source memory performance in older adults [published online January 12, 2017]. Cortex. doi:10.1016/j.cortex.2017.01.002.