Many people, when they sign up for a gym, or even when they decide to start a workout routine on their own, don’t know exactly what type of exercise they should do. But how do you decide whether to focus on aerobic exercises, such as running and cycling, or whether to focus on weight training? Which is better?

The answer actually lies in one question: what is your training goal? If your goal is to gain muscle mass, aerobic training will do little good. However, if your goal is to lose weight and improve your physical fitness, you are on the right track. On the other hand, if your goal is to gain muscle mass and increase physical strength, anaerobic exercises are where you should focus.

Aerobic and anaerobic exercises are two distinct types of exercise. The first is characterized by prolonged, low-load effort, while the second is characterized by movements that require a lot of strength immediately, such as weightlifting, for example. The two types, however, differ from each other mainly in the type of “fuel” used by the body to perform them. Find out more.

Two ways to generate energy for the body

To perform physical activities, the body basically depends on a single factor: available energy. This energy is produced, firstly, by the breakdown of adenosine triphosphate (ATP) molecules. The body then begins to transform glucose molecules into ATP.

Adenosine triphosphate molecules are the main source of energy in the human body, responsible for carrying out basically all of the body's tasks, from transporting substances within cells to the motor functions of muscles.

The ATP production process occurs in two ways. The first is through the synthesis of carbohydrates present in the body, obtained through food. Their breakdown generates two ATP molecules. This is a fast process that immediately transforms the glucose molecule into energy to be consumed immediately.

In the second process, the body uses glucose stores and adipose tissue (the body's fat layer) to create an enzyme called acetyl-coenzyme A (Acetyl-CoA), which reacts with oxygen, obtained through respiration, in a process called oxidative phosphorylation. This reaction produces eighteen times more energy than the previous process.

Despite releasing large amounts of energy, this is a process that depends on an extensive and time-consuming chain of physiological events to produce ATP again, so that, if by chance the activity is very intense in a short period of time, the body will immediately need more energy by seeking this charge in the carbohydrates stored by the body.

Aerobic or anaerobic (strength): differences and specificities

We have seen that there are two ways to generate energy so that the body can perform activities. One is through the breakdown of carbohydrates present in the body's stores. The other is through the reaction between oxygen and the enzyme Acetyl-CoA obtained through the burning of glucose or fats. The first process is called anaerobic, popularly known as strength exercise, and the second is called aerobic.

Anaerobic (strength) exercises

As we have seen, when a great effort is made abruptly, or in a short period of time, such as a shot put or a sprint in a 100-meter race, the body demands a significant amount of energy to be consumed immediately. The breakdown of glucose is the fastest way to create the fuel needed to perform the activity. This process does not depend on any oxygen molecules to be carried out.

We call exercises that fall under this category anaerobic, such as the aforementioned shot put, long jump, pull-ups, weight training, etc. These are exercises that focus on muscular explosion and physical strength.

Aerobic exercises

When we perform light but long-lasting physical activities, a huge amount of energy is required. However, the body has more time to produce it and can use other resources to generate ATP.

Glucose is an extremely important substance for brain functions and the body understands that consuming large amounts of this substance can be harmful to the proper functioning of the brain.

To generate enough energy to remain in exercise for a long time, the body resorts to the process of oxidative phosphorylation, as we saw above, which depends on the presence of oxygen and enzymes of the acetyl group obtained through the synthesis of glucose or fats.

Since glucose is a substance in the body, the body prefers to break down lipids to generate this enzyme that reacts to produce a significant amount of ATP, which will be gradually consumed during the activity.

Exercises that depend on this oxidation process of the acetyl enzyme are called aerobic exercises. These are lighter but prolonged exercises, such as walking, running, cycling long distances, jumping rope, etc. These consume oxygen to generate energy.

Which is the best?

When we talk about exercise, we must consider that good physical preparation and reasonable muscular strength must always go hand in hand. In other words, a combination of both types of activities is ideal for good performance in your training routine. There is no better or worse and it all depends on your goals.

Aerobic exercise is great for those who want to lose weight, as it uses fat burning as a source of energy to perform the activity. If you want to lose weight or even get in shape and reduce cholesterol, opt for this type of exercise. Light, long runs, walks and bike trails are excellent ways to “clear your head” while doing physical activities.

Mixing leisure and exercise is a great way to create a training rhythm and encourage maintaining an activity routine.

If your goal is to gain muscle mass and physical strength, opt for anaerobic exercises that consume carbohydrates to produce ATP. This modality does not use the enzymes obtained through the synthesis of fat, so they are not very functional in this sense. However, they generate great resistance and muscle tone, shape the body, correct posture, among other benefits.

This modality, however, requires a specific diet to ensure that your body has adequate energy levels to avoid the risk of burning lean mass in the ATP production process.

See in this other article how an adequate pre-workout diet is important for good performance in strength exercises.

Did you like the content? Now you can create an exercise routine that suits your personal interests without worrying about “doing something wrong”. Enjoy!