Aging is often accompanied by cognitive decline, memory loss and an increased risk of neurodegenerative diseases such as Alzheimer’s. Globally, over 47 million people live with dementia, a number expected to triple by 2050. Cognitive decline, however, is not inevitable and research increasingly highlights exercise as a powerful way to maintain brain health.
Beyond cardiovascular and muscular benefits, physical activity directly affects the brain through a biological dialogue between skeletal muscle and neural tissue, known as muscle–brain crosstalk (Pourteymour et al., 2025).Exercise influences brain structure and function through multiple mechanisms. Lifelong physical activity is associated with larger volumes of grey and white matter, reduced neuroinflammation and improved executive function, memory and decision-making. Aerobic activity increases hippocampal volume and stimulates neurogenesis in adults, supporting memory and learning. These findings indicate that the brain retains plasticity well into later life and can respond to lifestyle interventions.
Key to these effects are myokines, signaling proteins released by skeletal muscle during contraction. Brain-derived neurotrophic factor (BDNF) enhances synaptic plasticity, dendritic growth and neurogenesis. Both acute and chronic exercise raise circulating BDNF levels, correlating with improved memory and learning. Other myokines, such as macrophage colony-stimulating factor (CSF1) and vascular endothelial growth factor (VEGF), support microglial regulation, white matter integrity and angiogenesis. Cathepsin B promotes hippocampal neurogenesis, while lactate acts as a signaling molecule to enhance synaptic plasticity. Collectively, these signals create a protective and regenerative environment for neurons.
Exercise also affects myelination, the process of forming the fatty sheath around nerve fibers. Myelin declines with age but physical activity enhances formation, preserves existing fibers and reverses damage in animal models. In humans, lifelong exercise correlates with thicker myelin and fewer white matter lesions, improving motor control and cognition. Exercise further influences cholesterol metabolism, supporting oligodendrocyte function, myelin repair and amyloid-beta clearance, a protein linked to Alzheimer’s disease.
Genetic factors, such as apolipoprotein E (ApoE) polymorphisms, interact with exercise-induced benefits. ApoE4, the strongest genetic risk factor for Alzheimer’s, impairs cholesterol handling and is associated with reduced myelination and amyloid-beta accumulation. Exercise helps mitigate these effects by maintaining ApoE levels, reducing neuroinflammation, supporting synaptic plasticity and promoting amyloid clearance, demonstrating that even genetically at-risk individuals can benefit.
Exercise’s impact spans from prenatal development to old age. Maternal activity improves offspring neurodevelopment and cardiac autonomic health, while adulthood exercise preserves cognitive function, delays neurodegeneration and maintains hippocampal and prefrontal cortex integrity. In older adults, regular physical activity supports executive function, slows tissue loss and helps maintain independence.
Evidence consistently shows that exercise slows brain aging, enhances cognitive performance and supports neurological health. Through mechanisms including muscle–brain crosstalk, neurotrophic factor signaling, angiogenesis, myelination and cholesterol regulation, physical activity strengthens resilience against cognitive decline and neurodegenerative disease.
References:
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Yang J, et al. Cardiac BDNF regulates myocardial adaptation to swimming exercise. J Mol Cell Cardiol. 2022;165:21–33
Blanchard JW, et al. ApoE4-driven cholesterol metabolism dysregulation in oligodendrocytes impacts myelination. Cell Stem Cell. 2021;28:104–118
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