This review aims to compare different exercise prescriptions and their underlying metabolic mechanisms—namely aerobic training, resistance training, HIIT, and their combinations—in improving glycemic parameters, insulin sensitivity, pancreatic β-cell function, and HbA1c levels in individuals with T2DM, with a particular focus on AMPK–PGC-1α signaling, GLUT4 translocation, mitochondrial adaptations, and anti-inflammatory pathways. This evidence concerns the gene INS and type 2 diabetes mellitus.