Hormonal

Exercise-induced increases in arterial shear stress are the principal physiological stimulus for improving flow-mediated endothelial function and resistance artery remodeling in humans.

To improve your blood vessel health, you need exercises that create high blood flow and shear stress, not just those that build muscle size. High-intensity dynamic exercises (like running, cycling, or high-rep resistance training) are likely more effective for vascular adaptation than low-flow static exercises (like heavy isometric holds) because they generate the necessary shear stress stimulus.