Rhythmic skeletal muscle contractions during walking activate AMPK in myocytes and drive GLUT4 translocation to the sarcolemma, increasing insulin-independent glucose uptake and lowering circulating glucose and insulin concentrations.

Contraction-induced PGC-1α signaling increases mitochondrial biogenesis in skeletal muscle and myocardium, raising oxidative phosphorylation capacity and lowering mitochondrial reactive oxygen species emission.

Sustained increases in cardiac output and blood flow velocity raise laminar shear stress on the vascular endothelium, upregulating endothelial nitric oxide synthase and increasing nitric oxide bioavailability.

Nitric oxide diffuses into vascular smooth muscle, activates soluble guanylate cyclase, and raises cyclic GMP, producing smooth muscle relaxation that lowers peripheral vascular resistance and resting blood pressure.

Reduced visceral adipose mass lowers secretion of TNF-α, IL-6, leptin, and resistin while increasing adiponectin output, decreasing systemic low-grade inflammation and hepatic VLDL production.

Improved insulin sensitivity and reduced inflammatory signaling decrease arterial wall matrix metalloproteinase activity and collagen cross-linking, lowering arterial stiffness and slowing atherosclerotic plaque expansion.

Decreased sympathetic outflow and increased vagal tone lower resting heart rate, blunt catecholamine surges, and raise the threshold for ventricular arrhythmia.

Lower platelet aggregability, fibrinogen concentration, and plasminogen activator inhibitor-1 activity reduce intravascular thrombus formation and the probability of acute coronary occlusion.

The combination of reduced myocardial oxygen demand, improved coronary perfusion, and stabilized plaques decreases the incidence of fatal myocardial infarction, heart failure, and sudden cardiac death, lowering cardiovascular mortality.