Anaerobic exercise.
Anaerobic is a Greek term. It literally means "without air" and consequently "without oxygen". An exercise is defined as anaerobic, when it is performed in such high intensity that the body does  not have enough time to deliver the required amounts of oxygen to the muscles. In this case, anaerobic metabolism occurs, and carbohydrates, such as glucose and glycogen, are consumed.
An anaerobic exercise requires sudden and short bursts of energy. Examples of anaerobic exercise include heavy weight lifting, sprinting and any exercise which requires short and very intense performance. Anaerobic exercise is also used in bodybuilding. Most anaerobic exercises are taken place in sets.
In a short term, activities as above do not require a significant supply of oxygen to the muscle. In a prolonged exercise the glycogen supply in the muscle runs out and the body converts to aerobic metabolism. When aerobic metabolism sustains the workout, the performed exercise is cardiovascular and the required energy is obtained mainly from fats.
Anaerobic exercise is complementary to aerobic exercise. The very early stage of any physical exercise can be considered anaerobic. Anaerobic training contributes to athletic performance but it does not improve cardiovascular endurance as aerobic exercise does.
As it has been mentioned above, the muscles cannot maintain this intense, anaerobic performance for a long period of time. This happens, because eventually the muscles experience a burning sensation, as soon as the "lactic acid build-up" level is reached. During the anaerobic phase energy is released, in order to be available to the working muscles. This necessary amount of energy is produced by a
biochemical process, called anaerobic
glycolysis. The latest involves the conversion of the readily available sugars in the blood to lactic acid. Because this energy supply is limited, anaerobic exercise cannot be sustained for long periods of time. In the aerobic phase that follows, more oxygen supply is available, enabling the lactic acid to brake down to carbon dioxide and water and to release large amounts of energy.
In fact, most physical activities are a combination of aerobic and anaerobic exercise. The amount of each depends on how intensive the stage of the exercise is. In an aerobic activity, the limit at which the oxygen supplies run out and the body turns in anaerobic metabolism is called "anaerobic threshold". If the body is out of shape, its ability to take oxygen in and to use it efficiently is limited. In such a case, the anaerobic threshold is reached at low levels, in terms of exercise intensity and duration. As our body gets more physically fit, it can provide more oxygen to the muscles, the aerobic performance gets longer and more intense and the anaerobic stage takes place at a later stage.
Although aerobic activity is preferred more often for weight loss, since fats are burned, anaerobic exercise helps to the same direction by increasing the person's basal metabolic rate. |
