Progress in the Study of B-Cell Immune Metabolic Regulation Mechanisms in Exercise-Induced Fatigue: A Narrative Review

Exercise-induced fatigue refers to the reversible decline in neuromuscular function during physical activity, whose immune-metabolic regulatory mechanisms remain incompletely understood. Recent studies have revealed that B cells can regulate hepatic glutamate metabolism via secretion of transforming growth factor-β1 (TGF-β1), thereby influencing mitochondrial function in skeletal muscle, revealing a novel immune-metabolic pathway relevant to exercise-induced fatigue. This review synthesizes current evidence on immune regulation in exercise-induced fatigue, centering on the TGF-β1-driven glutamate axis linking the liver and skeletal muscle, cross-organ signaling, and hypotheses of central fatigue. We also discuss targeted interventions along this pathway to inform future basic research and clinical management of exercise-induced fatigue.