Aerobic exercise is any activity that uses the larger muscles of the body --- like the thigh muscles --- and is sustained for at least ten minutes at a time. It is called aerobic because activity of this type requires the body to take in a higher-than-normal amount of oxygen. The benefits of aerobic exercise (also called cardio or cardiovascular exercise) are many, but most notable are the benefits to the cardiovascular and respiratory systems.
Cardiovascular System
The heart is the body's hardest working muscle, and any aerobic exercise forces the heart to work harder . Over time, the heart becomes accustomed to the extra work, grows larger, and becomes more efficient. This efficiency carries over to all aspects of daily life. Several studies have been completed which show that the more physically active a person is, the less likely he or she will suffer from coronary heart disease. Further, a person who engages in aerobic activity on a regular basis is less likely to be overweight or obese; will see a reduction in bad cholesterol levels; and will benefit from an increase in insulin sensitivity. All of these things benefit the cardiovascular system.
Respiratory System
During aerobic exercise, the body uses more oxygen, and produces more carbon dioxide. This forces the lungs to work harder and to increase in capacity in order to handle the demands. After time, the lungs become more efficient and endurance increases, which causes more oxygen to enter the body's cells upon each inhalation.
Recommendations
The American Heart Association recommends that adults participate in 30 minutes of moderate-intensity cardio exercise five days a week. Exercise may be broken up into several short sessions during the day or done all at once. For maximum benefit, the activity should be sustained for at least ten minutes each time. Some examples of aerobic exercise are jogging, brisk walking, rowing, cycling, and swimming.
Caution
Anyone new to aerobic exercise should start slowly, and increase exercise intensity and duration in small increments. Feelings of dizziness, nausea, or light-headedness are indications to stop the activity immediately and seek medical attention. If you have any kind of medical history that includes heart, lung, or respiratory problems, ask your doctor's advice before starting any new exercise program.
