I’m sure you hear the terms aerobic and anaerobic all the time. The term aerobic has often been used synonymously with the term cardio and is sometimes confused with a type of fitness class from the 1970s. What exactly are aerobic and anaerobic exercises, and why does it matter?
It turns out that these are directly related to your metabolism and the way your body uses energy. The amount of energy your muscles keep stored at any given time only allows for about a second of maximum exertion and after that, your body needs to begin making more energy for itself. For the first couple minutes of a hard workout, your body will use carbohydrates in the form of blood sugar or glycogen (sugar stored in your muscles) to generate additional energy. These first couple minutes do not require additional oxygen to create the new energy, so it is called an anaerobic (no oxygen) process.
If you exercise extends longer than a couple minutes without a long enough break to allow your muscles to restore their energy, then your body begins to run out of glycogen and blood sugar to safely use and must find a new way to produce energy. Your body decides to start breaking down fats, carbohydrates, and even proteins to use as energy. If your workout lasts long enough, your body will even go as far as breaking down your muscles for energy! These metabolic processes require oxygen, which is why they are referred to as aerobic processes.
How you train determines what type of energy pathway you are using. If you are lifting weights, throwing a ball, or running a sprint, then you are using anaerobic processes to provide your body with energy. This type of exercise forces your body adapt to become better suited for short, explosive movements. Your muscles will start to store more energy and they will begin to grow larger. If you decide to go jogging, swimming, or dancing, you are using aerobic processes to fuel your body. The more you do these kinds of workouts, the more your body will adapt to utilizing and mobilizing fat, which could lead to a lower body fat percentage. Also, your ability to store and transport oxygen in your muscles will increase and your aerobic capacity will rise.
A good mix of aerobic and anaerobic activities are required to stay healthy and fit, but depending on your fitness goals you may want to choose to train one more often than the other. To lose weight, aerobic activities should be favored, while to gain muscle size and mass, anaerobic exercises should be your go to exercise type.