Blood flow throughout the body is effected increasing flow to the vital organs like the brain and kidneys while going into Sajda'h and Ruk'o. During Tash'had blood is squeezed out of the calves and thighs and directed towards the brain and upper part of the body thus over a period of time increasing the elasticity and tensile strength of the blood vessels that in the long term protects against clots and hemorrhages.
Sajda'h also aids in clearance of respiratory secretions that's the reason we hear many people clearing their throats after coming out of Sajda'h. Sajdah posture is exactly what the Pulmonologists recommend for chest physiotherapy for patients with Chronic Bronchitis, Emphysema, etc.
The focusing of eyes at specific points with the mind focused on reciting the Qur'anic verses is an excellent way to relieve stress.
