The Role of Exercise in Regulating Brain Health and Aging through Glymphatic Function.

Abstract

The glymphatic system is a recently discovered brain clearance pathway that removes metabolic waste, including toxic proteins, via cerebrospinal fluid flow along perivascular spaces. It helps maintain neural homeostasis, and its dysfunction is linked to neurodegenerative diseases like Alzheimer's. Emerging evidence suggests that physical exercise can enhance glymphatic function and promote cerebral clearance, offering a potential nonpharmacological approach to support brain health. In rodent studies, voluntary wheel running has been shown to increase glymphatic flux, likely through improvements in cerebrospinal fluid circulation, vascular pulsatility, and the exchange of interstitial fluid along perivascular routes. Exercise also upregulates the expression and polarization of aquaporin 4 on astrocytic endfeet, which is essential for directing fluid movement and facilitating efficient glymphatic transport, potentially reducing the accumulation of neurotoxic proteins such as β-amyloid and tau. Beyond these direct effects, exercise-induced enhancements in cerebral blood flow, arterial compliance, and sleep quality may indirectly optimize the physiological environment for glymphatic clearance. Together, these mechanisms suggest that regular physical activity is an established, noninvasive intervention to maintain cerebral homeostasis, accelerate metabolic waste removal, and support long-term cognitive function. This review summarizes evidence linking exercise to glymphatic function and its role in brain waste clearance and cognitive function.