What Are The Cardiovascular Benefits Of Regular Exercise?

During vigorous physical activity blood flow through skeletal muscles increases about tenfold and oxygen consumption of these muscles may increase a hundredfold. Thus regular exercise causes a person's arteries to become larger, so they can carry more blood. Also, more blood vessels open up in muscle tissue, providing new routes for delivering more oxygen. Particularly in the heart muscle is this an advantage, for then even if one artery becomes "clogged," blood supplied by auxiliary routes may be sufficient to keep the heart muscle from starving for oxygen and stopping.
Regular physical activity, too, strengthens the pumping action of the heart. So fewer strokes are necessary to accomplish the same results, allowing a conditioned heart to rest more. Sedentary persons, who have heart rates of eighty or more beats per minute, may significantly reduce this rate and permit their hearts to rest more by regular exercise.
But the special benefit of physical activity is that the strengthened heart operates more efficiently under stress.