BDNF and type 2 diabetes mellitus: Additionally, PA reduces mortality risk by enhancing cardiorespiratory fitness (VO2 max), preventing chronic diseases (e.g., type-2 diabetes [T2D] and cardiovascular diseases [CVD]), and activating survival pathways (e.g., AMPK/PGC-1α-mediated mitochondrial biogenesis, BDNF-dependent neuroprotection) (28).