Cardiovascular exercise is sometimes referred to as aerobic exercise, and some call it ‘cardio’ for short. Cardiovascular exercise is activity involving the large muscles, such as your legs. The word ‘aerobic’ refers to something that needs oxygen. During cardiovascular or aerobic exercise, oxygen gets continuously delivered to your muscles.
The heart is a muscle, or, more accurately, a group or “package” of muscles, similar in many ways to the muscles of the arms and legs. And just as exercise strengthens and improves limb muscles, it enhances the health of the heart muscles as well.
It’s generally accepted that cardio exercise helps reduce the risk of harm to the heart. Some research further attests to the link between exercise and a healthy heart based on findings that non-exercisers have a 49% greater risk of heart attack. The study attributed a third of that risk to sedentary lifestyle alone.
The benefits of regular cardio exercise are many:
- Diminished risk of heart attack
- Improved performance of the heart muscles
- Increased metabolism, resulting in more calories burned in day to day activities, thereby assisting in weight loss
- Improved lung capacity
- Stress reduction
In a long-term study of the health of people in the United States, the U.S. Public Health Service documented the chances of developing heart disease among various groups in the population. Long before any symptoms appeared, epidemiological research could identify high-risk groups.
Among the highest risk factors are:
- being male
- over 35
- a cigarette smoker
- high blood pressure
- high levels of certain blood fats
- and a family history of cardiovascular disorders.
Other researchers have added to this list another risk factor: the compulsive, hard-driving, highly anxious personality. The greater the severity, the greater the person’s overall risk.
These threats to the heart can be divided into two main categories: those beyond individual control, such as age, sex, and heredity, and those that can be controlled, avoided, or even eliminated. Among those in the second category are what cardiologists call “the triple threat.” These are:
- high blood pressure
- cigarette smoking
- and high cholesterol levels in the blood.
If you smoke a pack of cigarettes a day, your risk of having a heart attack is twice that of a nonsmoker. If you smoke, have hypertension, and eat a diet high in fats without any exercise at all, your risk is five times greater than normal.
If these risk factors endanger the heart’s health, what enhances its well-being and improves its odds of working long and well?
Obviously, quitting cigarettes and eating a low-fat diet will help. The next best thing you can do for your heart’s sake is to give it what it needs: regular cardiovascular exercise.
Following World Ward II, several large-scale statistical studies evaluated the relationship between physical activity and cardiovascular disease. One well-known survey compared 31,000 drivers and conductors of some bus companies. The more sedentary drivers had a significantly higher rate of heart disease than the conductors, who walked around the buses and climbed stairs to the upper level.
The why and how behind these statistics are best explained by classic experiments with dogs whose coronary arteries were surgically narrowed to resemble those of humans with arteriosclerosis. Dogs who were exercised had much better blood flow than those kept inactive.
Exercise seemed to stimulate the development of new connections between the impaired and the nearly normal blood vessels, so exercised dogs had a better blood supply to all the muscle tissue of the heart. The human heart reacts in the same way to provide blood to the portion that was damaged by the heart attack.
To enable the damaged heart muscle to heal, the heart relies on new small blood vessels for what is called collateral circulation. These new branches on the arterial tress can develop long before a heart attack — and can prevent a heart attack if the new network takes on enough of the function of the narrowed vessels.