Prediabetes represents a critical window for the development of type 2 diabetes, with exercise intervention serving as a core management strategy. Zone 2 aerobic exercise, characterized by low-to-moderate intensity and sustained fat oxidation, has recently attracted attention for its potential to improve glucose metabolism. This narrative review synthesizes domestic and international research to explore the underlying mechanisms by which Zone 2 aerobic exercise improves glycemic control in prediabetic populations, including enhanced mitochondrial biogenesis, improved fatty acid oxidation capacity, ameliorated insulin signaling pathways, modulation of chronic low-grade inflammation, and gut microbiota remodeling. Current evidence suggests that Zone 2 aerobic exercise can improve insulin sensitivity through multi-target, multi-pathway synergistic effects, thereby reducing the risk of diabetes progression. Future high-quality randomized controlled trials are needed to validate its long-term efficacy and optimal exercise prescription parameters.
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