Aerobic and Anaerobic metabolism

Aerobic metabolism is the way that your body creates energy through the combustion of carbohydrates, amino acids and fats in the presence of oxygen. Combustion means burning, which is why this called burning sugars, fats and proteins for energy.
aerobic metabolism is used for the sustained production of energy for exercice and other body functions.
Examples: walking, running or cycling with sustained effort.

Anaerobic metabolism: Is the creation of energy through the combustion of carbohydrates in the absence of oxygen. This occurs when your lungs cannot put enough oxygeninto the bloodstream to keep up with the demands ofyour muscles energy.
It´s generally used only for short bursts of actvity.

Differences of anaerobic and aerobic metabolism
Anaerobic metabolism is not as efficient as aerobic metabolism. A molecule of glusoce can only produce 3 ATP molecules under anaerobic metabolism, while it produces 39 with aerbic metabolism. ATP is what fuels the muscles.
Anaerobic metabolism can only use glucose and glycogen, while aerobic metabolism can also break down fats and protein. Intense bouts of exercicein the anaerobic zone and in the red-line zone with a heart rate over 85% of your maximum heart rate will esult in using anaerobic metabolism to fuel the muscles.
While your body will naturally use the energy parthways that will best get the job done, you have a choice in how strenuously you exercice. Training programs for different sports and activities are designed to make the best use of aerobic and anaerobic metabolism.