Physical Activity Relates to Lower Astrocytic Activation and Axonal Breakdown in Clinically Normal Older Adults

Physical activity is associated with >30% reduced risk of dementia. However, the biological mechanisms underlying exercise as a protective factor against cognitive decline remain unclear. Astrocytic activation and axonal breakdown, as measured by plasma glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL), respectively, are pathways disrupted early in cognitive aging and neurodegenerative disease. We aimed to examine whether an objective measure of physical activity (FitbitTM) related to plasma levels of GFAP and NfL in clinically normal older adults.