Mild Cognitive Impairment and Sarcopenia: Effects of Resistance Exercise Training on Neuroinflammation, Cognitive Performance, and Structural Brain Changes
Valeria Oporto-Colicoi, Alexis Sepúlveda-Lara, Gabriel Nasri Marzuca-Nassr, Paulina Sepúlveda-Figueroa
Abstract
Mild cognitive impairment (MCI) and sarcopenia are prevalent age-related conditions that often coexist and share common mechanisms such as chronic inflammation, reduced neuroplasticity, and impaired muscle function. Resistance exercise training (RET) has emerged as a promising non-pharmacological strategy capable of addressing both physical and cognitive decline. The aim of this narrative review is to synthesize preclinical and clinical evidence on the effects of RET in older adults with MCI and sarcopenia, with a specific focus on its impact on neuroinflammation, cognitive performance and structural brain changes. At the molecular level, RET activates anabolic pathways, including PI3K/Akt/mTOR, enhances neurotrophic support via BDNF, NT-3, and IGF-1, and promotes hippocampal neurogenesis through exercise-induced myokines such as irisin and cathepsin B. RET also exerts immunomodulatory actions by shifting microglia toward anti-inflammatory M2 phenotypes, attenuating reactive astrogliosis, and supporting oligodendrocyte precursor cell differentiation, thereby improving myelin integrity. Neuroimaging studies consistently report preservation of hippocampal and precuneus gray matter, as well as improved white matter connectivity following RET. Clinically, RET has demonstrated significant and sustained improvements in executive function, memory, and global cognition, with effects persisting for up to 18 months. Collectively, RET represents a multifaceted intervention with the potential to delay progression from MCI to Alzheimer's disease by integrating neuroprotective, anti-inflammatory, and anabolic effects. Standardization of RET protocols and identification of biomarkers of responsiveness are needed to optimize its role within multimodal dementia-prevention strategies.