Physical fitness and aerobic endurance

The term endurance is used quite a lot when it comes to the sporting world. The meaning of the word can hold great variation in the minds of different people. However, when it comes to sport, the word endurance refers to the ability of an athlete to sustain prolonged exercise for a long period of time. In order to maintain proper endurance, the circulatory and respiratory systems are required to supply energy to the muscles. The word aerobic means 'with oxygen', and refers to the body's use of oxygen in order to sustain physical activity. Endurance training seeks to develop the systems that produce energy.

Aerobic exercise and the body

Food is converted to fuel by the body. This is done through the use of several different energy pathways. To put it simply, the body uses nutrients to produce energy. This can be done with or without oxygen. As indicated earlier, aerobic metabolism refers to energy conversion with oxygen, while the opposite of this is anaerobic metabolism, which is an energy conversion that takes place without oxygen.

Often, a combination of both of these energy systems is required to supply the body with the fuel that it needs. The exact type of fuel supply will depend on the intensity and duration of the exercise. These factors will also decide on which method gets used at any given time. It should be pointed out that most of the body's energy is provided through the use of the aerobic metabolism. In order to boost endurance, most athletes will look to increase their exercise capabilities as much as possible. Exercising in this manner can be hindered by both fatigue and exhaustion.

Maximal Oxygen Uptake refers to the capacity of an athlete to perform exercise over a sustained period of time. This is normally closely linked with aerobic endurance. The maximum amount of oxygen that an individual can take in during exercise is measured in millileters per kilogram of body weight. This is normally considered to be one of the most accurate indicators of aerobic fitness and cardiorespiratory endurance. Typically, high class or elite athletes display a high level of maximal oxygen intake, or VO2 max, as it is also known. Genetic factors can also play a part when it comes to an individual's VO2 max. It is often found that elite athletes also have a higher proportion of slow twitch muscle fibers. This type of muscle fiber is more efficient when it comes to the usage of oxygen and aerobic metabolism.