Exercise Health Article

Role of Exercise in Disease Prevention

Studies have shown that exercise can have a direct effect on preventing heart disease, cancer, and other causes of premature death. Furthermore, participation in regular physical activity may reduce the rate of occurrence of these maladies. An inverse relationship exists between disease and exercise, meaning that with increased levels of physical activity there is a decreased prevalence for certain diseases. Currently, there is strong evidence that exercise has powerful effects on mortality, CAD (including blood lipid profiles), and colon cancer. Research has also confirmed that aerobic exercise can reduce high blood pressure, obesity, type II diabetes, and osteoporosis. In addition, stroke and several types of cancer (such as breast, prostate, and lung cancer) can also be reduced with regular physical activity.

Even more important, several of these factors are interrelated. For example, when an individual lowers his or her high blood pressure, the risk for heart disease, stroke, and kidney disease is also reduced. Another example is that exercise favorably alters blood lipid profiles. These profiles include measurements of total cholesterol (TC, complete count of all cholesterol in the blood), high-density lipoprotein cholesterol (HDL-C, the "good" cholesterol), low-density lipoprotein cholesterol (LDL-C, the "bad" cholesterol), and triglycerides (TRG, storage form of energy), which reduce the risk of plaque buildup in the coronary arteries, a sign of CAD.

Exercise Prescription

Adequate physical activity is dependent on having a well-rounded program that encompasses all aspects of improving health and preventing disease. A well-rounded program includes cardiovascular fitness, muscular strength and endurance, flexibility, posture, and maintenance of body composition.

The most effective way to participate in a well-rounded program is by following a simple mnemonic device called FITT (Frequency, Intensity, Time, Type). The FITT principle includes how many times a week one should exercise (frequency), how intense the workout should be (intensity), how long the workout is (time), and what modality to use (type of exercise). Modality is dependent primarily on what an individual prefers. This exercise prescription in based on an individual's fitness level when entering the exercise program, and ultimately upon the goals of the individual. For example, an untrained individual who wants to lose weight and likes to walk would be placed on a program of treadmill or outdoor walking (type), for thirty minutes a day (time), three to five times per week (frequency), and of light to moderate intensity (intensity).

A good example of an exercise program would include three stages. The first stage is a warm-up, where one should complete light calisthenics to activate and warm the muscles, immediately followed by stretching, which helps to maintain flexibility. The second stage is the conditioning stage, which consists of cardiovascular work to enhance the function of the heart and lungs and a resistance-training regimen to strengthen and tone major muscle groups, such as the quadriceps, hamstrings, chest, biceps, triceps, back, and abdominals. The final stage consists of a cool down, or reduction in heart rate to resting levels, as well as stretching again, since the greatest modification in flexibility comes from post-exercise stretching.

Maintenance of physical activity is important to maintain a healthy lifestyle. In addition, it is important to follow an exercise regime that will start slow and gradually increase as fitness level and exercise tolerance increases. The key is to complete at least thirty minutes of activity most days of the week in the form of activities that one enjoys, such as walking, jogging, swimming, aerobic dance, biking, skateboarding, or participating in a sport. This will enable an individual to reach the goals of Healthy People 2010, which include improving the quality of life through fitness with the adoption and maintenance of regular exercise and physical activity programs.

SEE ALSO SPORTS NUTRITION.

Robert J. Moffatt Sara A. Chelland