Aerobic Metabolism - Definition

Aerobic Workout on the Treadmill
Aerobic Workout on the Treadmill. Gary John Norman/Image Source/Getty Images

Aerobic Metabolism Definition

Aerobic metabolism is the creation of energy through the combustion of carbohydrates, amino acids and fats in the presence of oxygen. The body burns sugars, fats, and proteins. The only byproducts of aerobic metabolism of carbohydrates are carbon dioxide and water, which your body disposes of by breathing, sweating and urinating.

In the aerobic metabolic process, the human body uses a molecule of glucose to produce 36 ATP molecules.

ATP is what fuels the muscles. Anaerobic metabolism, which is used for vigorous muscle contraction, only produces 2 ATP molecules per glucose molecule, so it is much less efficient.

The body uses aerobic metabolism for energy throughout the day to fuel regular activity by the cells, muscles and organs. This is why you have a basal metabolic rate, a level of calorie-burning needed just to maintain the normal body functions, apart from physical activity calories burned.

Aerobic metabolism is also why your lungs absorb oxygen to be carried by hemoglobin in the blood to your tissues. The oxygen is used in aerobic metabolism to oxidate carbohydrates, and ends up attached to carbon in the carbon dioxide molecule that is excreted.

Why Do You Want to Use Aerobic Metabolism in Exercise?

An aerobic exercise is done at a heart rate below 85% of maximum heart rate and doesn't use vigorous muscle contractions. The body is able to maintain a constant energy stream by breaking down carbohydrates and fats with aerobic metabolic processes.

If your goal is to lose weight through exercise, aerobic metabolism is your friend as it takes fat out of the fat cells and burns it to produce energy for the muscles. It also burns up the available and stored sugars (carbohydrates) in your cells, so any excess won't be processed into fat. The food that you eat will replenish your available energy stores, so long as you don't eat more than your burn off.

During exercise, using aerobic metabolism for energy results in less muscle soreness afterward than occurs with anaerobic metabolism. It is the cleaner-burning process without byproducts that lead to soreness. Anaerobic metabolism results in producing lactic acid. You feel burning and fatigue quickly as it builds up in a muscle being contracted in strength training. It also leads to delayed onset muscle soreness, the aches you feel the next day. Strength training, jumping and sprinting areĀ  typical forms of exercise that use anaerobic metabolic processes.

At a moderate-intensity level of exercise, you are breathing enough and your muscles' need for ATP is slow and steady enough that you can break down glycogen into glucose and mobilize stored fat to break down for energy.

You can also take in carbohydrate that the body can use before all of the stores are depleted. Athletes who get this wrong experience bonking or "hitting the wall."

You can achieve the aerobic exercise zone by walking at a brisk pace where you may be breathing a little hard but still able to speak in full sentences. If you are ready to put aerobic metabolism into action, enjoy this aerobic walking workout.

Also Known As: fat-burning zone

Common Misspellings: arobic airobic

Examples: Walking uses aerobic metabolism to burn sugars and fats. Be sure to bring along walking snacks on any endurance walks of two hours or more.

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