Metabolism refers to the processes your body uses to break dow nutrients, form compounds the cells can use for energy and usa those compounds to fuel cellular functions. Your body secretes enzymes to break down food into sugars, proteins and fats. Then each cell of your body can take these in and use them in aerobic or anaerobic metabolic processes to form adenosine triphosphate (ATP), which is the fuel used in the cell.
The calories from food are burned in this way to produce energy in each cell. Your body´s overall metabolism includes muscle contraction, breathing, blood circulation, maintaining body temperature, digesting food, eliminating wastes and the functions of the brain and nervous system.
The rate at which you burn calories is called your metabolic rate.
During exercise, you not only increase metabolism in your muscles but also in your respiratory and circulatory systems.
You need a faster rate of breathing and heart rate to deliver oxygen and nutrients to your muscles. Your body also must work harder to prevent overheating, such as through sweating.
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.
Examples. when you go for a sprint when you are 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 t carbon dioxide and water. Instead, lactic acid is produced, which can build up in the muscles and degrade muscle function.
Anaerobic vs 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.
How anaerobic metabolism and lactic acid affect you during exercice
Lactid acid is a by-product of anaerobic glycolysis and anaerobic metabolism, both o which occur duing strebuous exercise. Although lactic acid is used as a fuel by the heart, an excessive amount of lactic acid in your skletal muscles slows down contractions, preventing you maintaining peak performance.
When your muscles use anaerobic metabolism, lctic acid is produced in your muscle cells. With modernate intensity exercice, it is able to difuse out of the cells, but with vigorous muscle contractions it builds up. As you build up more and more lactic acid, your muscles burn and are fatigued.
often, this is felt in activities like wieght liftng, but you canm reach it when running or cycling at a sprint. You are forced to back off and slow down so your muscles can recover and allowlactid acid to diffuse out of the cells. Lactid acid is further processed by the liver into glucose to use for fuel, completing cycle.
How your body uses aerobic metabolism:
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 basa metabolic rate, a level of calorie_burning needed just to maintain the normal body functions, apart from physical activity calories burned. A living body is always burning some calories, even at rest.
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 oxidize carbohydrates and the oxygen atoms end up attached to carbon in the carbon dioxide molecule that is excreted.
The only byproducts of the process of aerobic metabolism of carbohydrates are carbon dioxide and water. Your body disposes of these byproducts by breathing, sweating and urinating. Compared with anaerobic metabolism, which produces lactid acid as well, aerobic metabolism produces bproducts that are easier to remove from the body.
