Aerobics And Anaerobic There are three main energy systems that fuel all human activity. The three metabolic energy pathways are the phosphagen system, glycolysis and the aerobic system. Almost all changes that occur in the body due to exercise are related to the demands placed on these energy systems. Furthermore, the efficacy of any given fitness regimen may largely be tied to its ability to elicit an adequate stimulus for change within these three energy systems. Energy is derived aerobically when oxygen is utilized to metabolize substrates derived from food and liberates energy.
An activity is termed aerobic when the majority of energy needed is derived aerobically. These activities are usually greater than 90 seconds in duration and involve low to moderate power output or intensity. Examples of aerobic activity include running on the treadmill for 20 minutes, swimming a mile.
Energy is derived anaerobically when energy is liberated from substrates in the absence of oxygen. Activities are considered anaerobic when the majority of the energy needed is derived anaerobically. In fact, properly structured, anaerobic activity can be used to develop a very high level of aerobic fitness without the muscle wasting consistent with high volume aerobic exercise! These activities are of less than two minutes in duration and involve moderate to high-power output or intensity. There are two such anaerobic systems, the phosphagen (or phospocreatine) system and the lactic acid (or glycolytic) system. Examples of anaerobic activity include running a 100-meter sprint, squatting, and doing pull-ups. Anaerobic and aerobic training support performance variables like strength, power, speed, and endurance. We also support the contention that total conditioning and optimal health necessitates training each of the physiological systems in a systematic fashion.