Effects of One-year Exercise on Neurocognitive Function and Brain Volume in Cognitively Normal Older Adults

Current evidence is inconsistent on the benefits of aerobic exercise training (AET) for preventing or attenuating age-related neurocognitive decline in older adults. PURPOSE: To investigate effects of a 1-year progressive, moderate-to-high intensity AET on cognitive function, brain volume, and cortical thickness in cognitively normal older adults. METHODS: We randomized 73 cognitively normal older adults to 1-year AET or stretching and toning (SAT, active control) arms. Primary outcome was a total cognitive composite score calculated from 11 neuropsychological test scores encompassing inductive reasoning, long-term and working memory, processing speed, and verbal domains. Secondary outcomes included brain volume and cortical thickness assessed by MRI. Cardiorespiratory fitness was measured by peak oxygen uptake (VO2). RESULTS: Peak VO2 improved by ~10% in the AET group while the negligible change was observed in SAT group after 1-year exercise interventions (p < 0.05). Cognitive composite scores improved in both the AET and SAT groups (p < 0.05), although no group difference was observed. Brain volume (hippocampal) and cortical thickness (mean, prefrontal, precuneus, and precentral) decreased in both groups (p < 0.05), reflecting normal aging. However, compared with the AET group, the magnitude of reductions in hippocampal volume was attenuated in the SAT group (p < 0.05). Individual analysis exhibited a positive correlation between changes in peak VO2 and global cognitive composite score (r = 0.275, p = 0.049). CONCLUSIONS: Our findings suggest that both AET and SAT may improve neurocognitive function in cognitively normal adults even though they may not prevent age-related reduction in brain volume and cortical thickness.