The word aerobic means with oxygen. It applies to those physical efforts and exercises that promote an increase in the air volume inspired while it's being done. These exercises make muscles work and, of course, consume more oxygen than when resting; but they never consume more oxygen than that inspired (which means the whole exercising is performed with oxygen, that is, aerobically). On the other hand, if an effort is maintained for too long or is really fast, the muscles involved will consume more oxygen than that present in the body, filling the blood with an excess of CO2, forcing the person to stop the effort and let the muscle rest and recover from the hard work and regain all the oxygen it needs.
The benefits of aerobic excercising are that it improves our body, more accurately speaking, the circulatory system. The cardiac muscle is able to develop resistance when making an effort. By making it work during a relatively long time at a higher rate than it normally does, it increases its performance. It will be better prepared for situations that may require its quick response, and will function effortless under normal conditions.
Aerobic activities also tune up blood vessels to adequate them to the heart's new capabilities. The cardiovascular effort maintains these vessel's tissues in a good shape, makes them resistant and flexible, and the blood flows through them without any trouble. Therefore, these physical activities (when performed regularly) represent an immense benefit for the body, preventing several cardiovascular diseases, and also acting as a very important regulator of the arterial tension (a.k.a. blood pressure).
These exercises effects also increase the level of HDL Cholesterol in the blood. HDL Cholesterol is also known as good Cholesterol, because it helps decreasing the size and amount of deposits of lipids.
This means that aerobic activities help you burn fat and control your weight. They are a necessary companion for an effective weight-loss diet.
The consequences of natural aging, like the decrease in physical resistance and muscular mass, flexibility, articular problems, slower metabolism and reactions, and many more can be fought against by doing physical exercise, especially on those people who have lived a sedentary life. Last, but not least, the benefits of aerobic activities brings an integral wellness, which is reflected in a better mood, self esteem increase, sociability and a strengthened self confidence.