What is metabolism, anabolism and catabolism?

If you are a student or avid bodybuilder, you may have heard the words metabolism, anabolism, and catabolism, but didn't know exactly how to differentiate between them or their respective meanings.

In this text we will see the importance of each one in our organism and how this can influence your results (or help you in your studies).

What is metabolism?

For the body to function, numerous biochemical reactions that occur at the cellular level are necessary.

The set – the whole – of these reactions is defined as metabolism.

Within these numerous biochemical reactions are divided into two types: anabolism and catabolism.

nabolism

All reactions that generate energy storage and construction of new tissues in the body are part of anabolism.

During an anabolic process, less complex molecules, known as substrates, come together to synthesize more complex molecules.

The synthesis (creation) of proteins in muscle tissue from amino acids is an anabolic process.

The formation of glycogen from the grouping of glucose molecules, also in muscle tissue, is considered another type of anabolism.

These processes occur, for example, after a strenuous resistance training session when we ingest carbohydrates and proteins.

Carbohydrates will be converted into glucose and, in part, will be transformed into glycogen.

Proteins will provide the amino acids necessary to generate the synthesis of new proteins, something fundamental during the process of muscle hypertrophy .

Anabolism only occurs when there is a supply of sufficient energy and substrates to sustain its reactions.

It is through the anabolic process that we maintain and regenerate various tissues and organs in the body.

Catabolism

On the opposite side of metabolism reactions, we have catabolism.

During a catabolic process, our body will perform the opposite process of anabolism, dismantling more complex molecules and turning them into simpler molecules.

This process is capable of increasing the availability of substrates available to the organism.

The most common example of catabolism is the process of food digestion where the body breaks down the nutrients present in the food, transforming them into simpler elements to be used by metabolism (including anabolic processes).

Proteins present in a food will be transformed into amino acids and these, through several other processes, will be placed into the bloodstream to be used by the body.

Another common example of catabolism (and the least desirable) occurs when there is a shortage of energy in the body and to maintain the levels of available substrates the body “destroys” its own tissues to obtain amino acids and glucose that will later be used as energy.

During a weight training session, the body is inevitably forced to do this to meet its energy needs.

Because of this, it is clear that anabolism, in this case muscle growth, does not occur when we are training.

In fact, during training, we are losing muscle mass.

Muscle mass building will occur during the rest period and only in the presence of sufficient substrates (glucose and amino acids) for the hypertrophy process to occur.

A steel cable between anabolism and catabolism

Anabolism and catabolism occur all the time in the body and in a transient manner.

What will define whether you will be “anabolizing” more than “catabolizing” is the final result of these reactions through metabolic balance.

If there was more anabolism than catabolism, in the end we will have a positive metabolic balance.If there was more catabolism than anabolism, in the end we will have a negative metabolic balance.If the quantity of both is equal, the balance will be zero.

The balance between one and the other goes far beyond the quantity of substrates available.

They are also regulated by the hormonal system, where some hormones act as signalers and triggers for these processes.

For example: the hormone cortisol is capable of triggering catabolism, generating a rapid breakdown of tissues to quickly generate glucose in stressful situations.

Testosterone and insulin do the opposite, signaling muscle anabolism.

That's why synthetic forms of testosterone (and even insulin) are used to increase muscle mass.

a) If the amount of anabolism was greater than that of catabolism, we will have a positive metabolic balance. 
b) If the amount of catabolism was greater than that of anabolism, we will have a negative metabolic balance. 
c) If the amount of anabolism was equal to that of catabolism, we will have a zero metabolic balance.

Catabolism and anabolism are regulated by the hormonal system, where some specific hormones act as signals and triggers of these metabolic states.