ABSTRACT
In sports events or strenuous exercise lasting more than 1 minute, the predominant mode of energy production is aerobic. Performance is limited by the oxygen that is delivered to and used by the active muscles. Genetic factors aside, the level of performance is determined by the nature of training, which can affect both central and peripheral physiological factors. In most cases, the limiting factors for maximal oxygen uptake are cardiac output and the oxygen-carrying capacity of the blood.
