Physical activity promotes cardio-respiratory endurance, muscular strength, muscular endurance and muscular flexibility, as well as good body composition. The benefits of regular physical activity include improved quality of life and greater longevity. In their recommendations on physical activity, the Centers for Disease Control and Prevention and the American College of Sports Medicine state that the benefits of physical activity include a number of factors that lowered the risk of coronary heart disease: improved blood lipid profiles, better resting blood pressure in borderline hypertensives, improved body composition, better glucose tolerance and insulin sensitivity, better bone density, immune function, and psychological function.
Physical activity is also protective. Epidemiologic studies show that low levels of activity and fitness are associated with markedly increased all-cause mortality rates. It is estimated that of 250,000 deaths per year in the United States, approximately 12% of the total are attributed to a lack of regular physical activity.
Dr. Paffenbarger conducted a large study of 16,000 Harvard alumni. His research showed that for every hour spent exercising, subjects could add four or more hours to their life. The additional hours of life are especially appealing because it’s not just the added hours that you experience but also a higher quality of life. Physical activity is certainly a good investment, at least when it comes to time and health!
Dr. Blair reported in the Journal of the American Medical Association, exercise was shown to be protective against coronary heart disease and cancer. Physical activity was also shown to be a stronger predictor of mortality rate than high blood pressure, smoking, and high cholesterol. The researchers also found that physically fit people with any combination of smoking, elevated blood pressure, or elevated cholesterol levels had lower death rates overall than low-fit people with none of these problems. In other words, this research indicated that if a person smokes and has high blood pressure but is physically active, his or her chances of dying prematurely are lower than someone who does not smoke and does not have high blood pressure but is inactive. This demonstrates the powerful protective effect of physical activity and its ability to promote health and well-being.
An expert panel—after reviewing physiological, epidemiological, and clinical evidence—formulated a recommendation for physical activity. The expert panel included the American College of Sports Medicine and the American Heart Association. They have given us the following physical activity guidelines: To promote and maintain health, all healthy adults aged 18-65 years need moderate-intensity aerobic physical activity for a minimum of 30 minutes five days each week OR vigorous-intensity aerobic activity for a minimum of 20 minutes three days each week. Also, combinations of moderate and vigorous intensity activity can be performed to meet this recommendation. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk, will accelerate the heart rate.
Exercise can be accumulated toward the 30-minute minimum as long as the exercise lasts at least 10 minutes. It is also recommended that eight to ten exercises be performed on two or more non-consecutive days each week using the major muscle groups. To maximize strength development, a resistance (weight) should be used that allows 8-12 repetitions of each exercise. People who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities, or prevent unhealthy weight gain will likely benefit by exceeding the minimum recommended amount of physical activity. Moderate or vigorous-intensity activities should be performed in addition to light intensity activities frequently performed throughout the day.
Although moderate physical activity such as brisk walking is safe for most people, we recommend that you talk to your doctor before starting a new exercise program.