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 oxygen into the bloodstream to keep up with the demands of your muscles for energy. It generally is used only for short bursts of activity, such as when you sprint when running or cycling or when you are lifting heavy weights up with the demands of your muscles for energy. It generally is used only for short bursts of activity, such as when you sprint when running or cycling or when you are lifting heavy weights.
When there isn’t enough oxygen in the bloodstream, glucose and glycogen cannot be fully broken down to carbon dioxide and water. Instead, lactic acid is produced, which can build up in the muscles and degrade muscle function.
Aerobic metabolism is the way 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 is called burning sugars, fats, and proteins for energy. Aerobic metabolism is used for the sustained production of energy for exercise and other body functions. Examples of exercises that use aerobic metabolism include walking, running, or cycling with sustained effort.
Your body will often switch between aerobic and anaerobic metabolism during sports and exercise activities that require short bursts of sprints as well as sustained jogging, such as in soccer, tennis, and basketball.