Cardiovascular Training
Cardiovascular training is strengthening the heart and lungs by working the cardio vascular system. The heart, being a muscle, needs exercise to function efficiently. The normal mild beating it performs in day to day life is not enough. The heart like any other muscle has to be driven harder if it is to be stimulated to be strengthened. Many cardiologists also believe that exercising the heart also increases its efficiency. That is, the heart's main function (pumping blood) is done at a lower cost (fewer beats per minute). That can supposedly improve your chances of surviving a heart attack.
During exercise, the blood vessels that feed the heart open wider and the concentration of cholestrol within the blood decreases. Both these actions may cut down the fat accumulations within the blood vessels, accumulations that might cause a heart attack or stroke. Exercise may also help stimulate the formation of new blood vessels that can supply it with blood. It also tones the body's blood vessels, usually reducing blood pressure - an important factor in heart attacks.
Activities such as running, jogging (treadmill), road marching, bicycling, swimming, cross-country skiing, rowing, stair climbing, and jumping rope place an extra demand on the cardiovascular and respiratory systems. During exercise, these systems attempt to supply oxygen to the working muscles. Most of this oxygen is used to produce energy for muscular contraction. Any activity that continuously uses large muscle groups for 20 minutes or longer taxes these systems. Because of this, a wide variety of training methods is used to improve cardiorespiratory endurance.