Cardiovascular Fitness: A Review

There is a lot to know about cardiovascular fitness. That includes what cardiovascular fitness is, some benefits of good cardiovascular fitness, and things you can do to keep your heart and blood vessels in good shape.

Cardiovascular fitness is the condition of your heart and blood vessels . You can remember that by recalling that cardio means heart, and vascular means blood vessels. Your heart is a two-sided pump. Each side has an Atrium (where the blood collects), and a Ventricle (a forceful pump that sends blood from the body). The right side of the heart (pulmonary pump) sends blood to the lungs to exchange oxygen and carbon dioxide. The left side (systemic pump) sends the oxygenated blood to the body. The vascular system is made up of your arteries (which take blood away from the heart), capillaries (very small vessels which allow gasses and nutrients to be exchanged), and veins (which bring blood back to the heart). Within these vessels is blood, which is made up of plasma (watery substance), platelets (which allow clotting), white blood cells (to fight infection) and red blood cells (which have hemoglobin to carry oxygen). A lack of red blood cells is called anemia.

The amount of work being done by the heart can be established by measuring the Pulse. An average resting pulse rate is around 70 beats per minute. Blood pressure is the amount of force being put on the blood vessels. 120/80 is an average blood pressure. Over 140/90 is considered high. The top number is the Systolic Pressure, or the pressure on the vessels when the heart pushes. The bottom number is the Diastolic Pressure, or the pressure on the vessels between beats of the heart.

Cardiovascular Disease

Cardiovascular disease is the leading cause of death in the United States. The most common type is Coronary Artery Disease. This is caused by a build up of fatty deposits (plaque) inside the walls of arteries. The fat in your blood (cholesterol) can be divided into two types: High Density Lipoproteins (HDL=good) and Low Density Lipoproteins (LDL=bad). Too much LDL causes the fat cells to stick to the walls of vessels. This build-up causes the arteries to become narrower (called Atherosclerosis). This plaque may eventually harden leading to arteriosclerosis (or hardening of the arteries). If a complete blockage of a vessel in the heart take place a myocardial infarction, or heart attack, occurs. A blockage in the brain is called a stroke.

Risk factors for cardiovascular disease include heredity, age, gender, lack of exercise, obesity, cholesterol levels, smoking and stress. Many, but not all, of these factors are controllable.

Exercise and the Cardiovascular System

Regular aerobic (long duration exercise which uses oxygen) exercise will make the heart larger, stronger and more efficient. More blood will be pumped out with each beat (stroke volume) so more blood can be pumped each minute (cardiac output). This in turn will cause a decrease in both resting heart rate and blood pressure. In addition the body uses oxygen better as a result of cardiovascular exercise. By improving your cardiovascular fitness, you are able to get more oxygen to your muscles, so they can work longer and more efficiently. The measurement that indicates how efficiently your body uses oxygen is called Maximal Oxygen Uptake (abbreviated VO2 Max).

To improve cardiovascular fitness, you should exercise at least 3 days/week, for at least 15 minutes in your target heart rate zone. Target heart rate is between 60-85% of your maximum heart rate (220-age). You can tell if your exercise is too hard by checking your recovery heart rate. 5 minutes after exercise, your heart rate should be 120 or lower. After 10 minutes, heart rate should be below 100.

An exercise session also should include a warm-up (5-10 minutes), and a cool down after exercise. Activities that may be used for cardiovascular conditioning include: walking, jogging, swimming, biking, jump roping, roller-blading and aerobic dance.