Anaerobic
Anaerobic is a technical word which literally means without air (where “air” is generally used to mean oxygen), as opposed to aerobic.
Anaerobic exercise is typically used by athletes in non-endurance sports to build power. Muscles that are trained under anaerobic conditions develop biologically differently giving them greater performance in short duration-high intensity activities.
Aerobic exercise, on the other hand, includes lower intensity activities performed for longer periods of time. Activities like walking, running, swimming, and cycling require a great deal of oxygen to generate the energy needed for prolonged exercise.
There are two types of anaerobic energy system, the ATP-PCr energy system, which uses creatine phosphate as the main energy source, and the lactic-acid (or anaerobic glycolysis) system that uses glucose (or glycogen) in the absence of oxygen. The latter is an inefficient use of glucose and produces by-products that are thought to be detrimental to muscle function. The lactic-acid system is the dominant energy system during high to maximal intensity exercise over short durations (up to about 1 minute), but the lactic acid system can still provide a proportion of the required energy during aerobic exercise, as the body has the capacity to get rid of the anaerobic by-products at a certain rate. The efficiency of by-product removal by muscles can improve through training.
