How Muscles Grow: Balance Between Anabolic and Catabolic Process

When you are training the body will go through processes called anabolism and catabolism. Anabolism in muscles refers to building of muscle tissue. Catabolism in muscles refers to breaking down of the muscle tissue. Depending on your condition, intensity of your training, quality of nutrition and sleep, the body can go either way.

In this article, I will share information on how muscle building work and how anabolism and catabolism play role in muscle development.

Anabolic Process

The anabolic process refers to the building up of muscle tissue. It involves the synthesis of new proteins from amino acids (muscle protein synthesis), which helps muscles grow larger and stronger. This process is triggered by factors such as resistance training, adequate nutrition (especially protein), and hormones like testosterone and growth hormone. During anabolism, the body repairs and builds muscle fibers that have been stressed or damaged during exercise, resulting in increased muscle mass and strength over.

Catabolic Process

The catabolic process refers to the breakdown of complex molecules into simpler ones, releasing energy. In muscles, catabolism involves the degradation of muscle proteins into amino acids, which the body uses for energy, especially during periods of intense exercise, inadequate nutrition, or stress. Catabolic hormones like cortisol and adrenaline trigger this process. If the body lacks sufficient nutrients or rest, it may break down muscle tissue for energy, leading to a loss of muscle mass and strength. Catabolism is the opposite of anabolism, and both processes are essential for maintaining overall metabolic balance in the body.

Catabolism is Required for Anabolism

When you look at how catabolism work, it may sounds horrible, however, catabolism is needed for promoting anabolic process. In simple term, the muscle does not grow or get stronger without stimulus, typically any form of exercise that promotes catabolism.

Catabolism can occur in sedentary lifestyle. However, this type of catabolism is due to the body realizing that muscle mass and strength is not needed for the lifestyle that you have. This process is also known as atrophy. Having muscle mass is very energy inefficient for the body. This is similar with the car. Compared with V4 engine to V12 engine, V12 is larger in size and need more fuel than V4 engine car. Therefore, V12 engine cars need more fuel but has more horsepower.

Muscles that are not being utilized will eventually recognized as "not necessary". That is why people who have larger muscle or have active lifestyle need more food to maintain the muscle mass and size and need to be stay active to stimulate the muscles. This is also a reason that we should be exercises on regular basis and ideal to take part in some form of resistance training 2-3 times per week to promote a catabolic process.

Although, catabolism is necessary for starting the muscle development, we cannot keep this process going for a long time or muscle recovery may not happen and may not see results you are looking for, despite the effort at the gym. At some point, ideally earlier point, switching from catabolic process to anabolic process is necessary.

Protein for Anabolic Process

One of the important anabolic processes is called muscle protein synthesis.  Muscle protein synthesis is the process by which the body builds new muscle proteins from amino acids. This process is a key part of the anabolic phase, helping muscles grow and repair after exercise. Muscle protein synthesis is stimulated by resistance training, adequate protein intake, and certain hormones like testosterone and growth hormone. When muscle fibers are damaged during exercise, the body uses amino acids to repair and strengthen them, leading to increased muscle mass and improved strength over time.

The body will look for protein or amino acid from anywhere. When the blood amino acid concentration is low, due to inadequate protein or amino acid consumption, the body will look for other part of the body to take the amino acid. For example, when you perform biceps curls, catabolic response happens in biceps. If the amino acid is not available in your bloodstream, the body may take amino acid by breaking down muscles in the leg (for example) and send it to the biceps. This process has been studied and documented.

Therefore, protein in take is very critical portion of muscle development. Term protein is coming from Greek word proteios, which means "primary". When protein was first studied, scientists realized that the protein is the most important macronutrients (compared with carbohydrates and fat) to our body. In muscle development, protein or amino acid intake is critical to transition the body from catabolism to anabolism.

After training session is done, the body will start the muscle protein synthesis, which may last for about 2-3 hours. However, catabolic process from the training session is still in progress and need to switch over. So it is important to refuel the body with protein (ideally 25g or more) 30-60 minutes after the training session. Reason why it is not immediately after is because blood circulation is focused towards muscles and not so much in digestive system. Also, first 20-30 minutes post training is when the body is switching from sympathetic nervous system (fight or flight) to parasympathetic nervous system (rest and digest).

This means, body is not ready to absorb or digest. Ideally, after the training, you should stretch and take shower then consume protein products. For maximum benefit, it is ideal to add carbohydrate such as banana to go with protein. What carbohydrate will do is to promote insulin secretion which may help bring in nutrients to the muscles faster. This is especially important for those who train hard because of possible cortisol increase, which triggers catabolic response.

Protein and amino acids can promote insulin (not as much as carbohydrate) so those who are working on fat loss, may need to keep the carbohydrate intake low even after the training.

Extending Muscle Protein Synthesis

Out side of training session, it is ideal to consume protein to sustain muscle protein synthesis. This is to minimize the catabolic effect and sustain muscle development process.

After exercise, muscle protein synthesis remain elevated for about 4-6 hours. Let's say you've had protein or amino acids (from food or supplement) after your session. It is ideal to consume protein source 3-4 hours after that. For example, if you had a training at 7am and finished at 8am, you should be consuming some form of protein before 9am. Then, around 12-1p you should have your lunch with some protein such as chicken, meat, fish, beans, nuts, lentils and so forth. This will help extend the duration muscle protein synthesis. Most likely, you already had protein with supplement after the training, therefore, you should have whole food protein source so that you can get other vitamin and minerals, which are also essential for muscle growth.

Then, ideally, you want to get some sort of protein or amino acid in between lunch and dinner. This can be protein or amino acid powder mixed with water or protein powder. This can also extend the duration of muscle protein synthesis until dinner time.

Ways to Minimize Catabolism

Catabolic response has to happen for anabolic process to start. However, lowering catabolic effect as soon as possible is also necessary to have a better anabolic response. When you review catabolism it's characteristics you can learn that after the training is done the cortisol level is also elevated. Therefore, to minimize catabolic effect it is necessary to lower the cortisol level. There are few things you can do.

• Stretch

• Shower

• Sleep

• Carbohydrate

• Glutamine

Stretch and shower after the training helps relax the muscles which also may help reduce cortisol. When your schedule is tight, this may become challenging, however, if possible try spend time on either one.

Carbohydrate (ex: fruits, rice, potatoes, etc.) is known to lower the cortisol level. Glutamine (ex: meat, dairy, eggs, beans, nuts, supplement, etc.), though it doesn't get much spot light, is beneficial nutrients. Glutamine is a primary energy source for the intestine which also help immune cell function. Glutamine is also a building block for muscle tissue and can also promote muscle protein synthesis (anabolism). Glutamine can also help metabolic health and brain function.

Proper sleep is also important for muscle growth. Lack of sleep will raise the cortisol and may lead to catabolism, which will negatively impact muscle growth. Prioritize your sleep schedule as much as you can and get at least 7 hours a night.

Summary

In ideal world, after the training session is done, use stretching and shower to lower the cortisol level. Then you can create protein shake mixing with protein powder, glutamine (supplement) and carbohydrate (ex: banana) which will refuel the body and optimize the muscle protein synthesis response. Throughout the day, using meals and snacks to consume protein and amino acids will maintain high blood amino acid concentration which can prolong the effect of muscle protein synthesis you've started with your training session. Create habit of 7 hours of sleep a night will also help muscle to develop efficiently.

Kota Shimada