If aliens from another planet watched American television for a week, they might get the impression that Americans are obsessed with good-looking muscles. After all, there are countless exercise machines and videos that guarantee better abdominal muscles, firmer thighs and butts, and bulkier arms and chests.
Exercise your heart
for real fitness
One muscle that we don't think of as "good looking," is by far the most important to keep in shape -- the heart. More people die of cardiovascular (heart and blood vessel) diseases than any other condition.
The causes of cardiovascular disease are multi-factorial and not fully understood. But, we do know the major risk factors associated with heart disease include aging, having a family history of heart disease, smoking, high blood pressure, high blood cholesterol levels, a sedentary lifestyle, and being overweight. Some of these factors are out of our control. However, some we can change.
Staying physically active is one of the easiest risk factors to control. The type of exercise that strengthens the heart is what we commonly call aerobic exercise. This is the type of exercise that can be continued for long periods of time such as walking, jogging, hiking, swimming, cycling, or just about any type of continuous physical activity. If you have been active for most of your life, then keep it up. If you have lapsed into a couch potato lifestyle, it is never too late to get more active. Just moderate amounts of physical activity provide substantial health benefits.
If you are just coming back from an extended vacation on the couch, remember to start back gradually. Just like other muscles, the heart can get out of shape. During the stress of physical activity, the heart is actually at greater risk of a heart attack. This is why it is recommended to get your doctor's clearance before making radical changes in physical activity level. This is especially important if you are over 40. Your doctor may recommend a stress test to screen for possible "silent" heart disease.
Moderate physical activity uses approximately 150 to 200 calories of energy per day and adds up to about 1,000 calories per week. Examples include walking about two miles, bicycling five miles in about 30 minutes, active dancing for about 30 minutes, pushing a stroller one and a half miles in 30 minutes, swimming laps for 20 minutes, or stairwalking for 15 minutes. In general, this means vigorous exercise for 20 minutes three times per week or moderate intensity physical activity for 30 minutes five times per week.
The American College of Sports Medicine recommends engaging in activities that use large muscle groups and can be maintained for 20 to 60 minutes of continuous aerobic activity three to five times per week. This includes anything that gets heart and lungs working significantly more than usual. In addition to strengthening the heart muscle, regular exercise can help reduce high blood pressure and increase blood levels of HDL cholesterol ("good" cholesterol). Regular aerobic exercise also makes the body better at burning fat and helps normalize the appetite.
Exercise alone will not prevent cardiovascular disease. You can still develop heart problems related to other risk factors. But, exercise is one of the most important components of a healthy lifestyle. The adage "use it or lose it" refers to the heart as well.
Alan Titchenal, Ph.D., C.N.S., is a sports nutritionalist in the
Department of Food Service and Human Nutrition,
University of Hawaii-Manoa.
Joannie Dobbs, Ph.D., C.N.S., is a food and nutrition consultant
and owner of Exploring New Concepts, a nutritional consulting firm.
She is also responsible for the nutritional analyses indicated
by an asterisks in this section.