Most athletes are familiar with or have some understanding of the concepts of aerobic and anaerobic respiration at the cellular level. During exercise, muscle contraction requires energy (ATP), which is supplied by both the aerobic and anaerobic metabolism of nutrients. Short bursts of high intensity exercise mainly utilize anaerobic energy sources, while exercise enduring longer than 3-5 minutes will utilize energy provided by aerobic metabolism. Aerobic power may be illustrated physiologically by the running of periods longer than 3-5 minutes. In order to run a marathon, much oxygen will be required to complete the race. Long distance runners train their bodies to utilize oxygen in the most efficient way to be able to win the race. Anaerobic power may be illustrated by running a short distance (sprint) race. In order to run a 100 m. dash, very little oxygen is required. Your body is running almost totally on anaerobic power because the race is over by the time your body has a chance to replenish oxygen to the cells.
