Unfortunately, for every decent personal trainer, nutritionist, expert with an academic position, and serious journalist who collaborates for web journals and other similar magazines, there are a much larger number of people who, for the sake of likes and attention, perpetuate misinformation about a substance that is probably one of the most studied and used supplements.
I will not discuss dosage, directions, usage, etc. What I want to do is help those people who are starting their fitness journey and are probably already in contact with people on social media who make good money selling or advertising supplements. Let me be clear on one point: Creatine, when used as it is supposed to be used, for the conditions at the base that need to be used, etc., is a solid and effective supplement. Let me be even clearer: it is a great supplement.
But maybe not for the reasons that some of you may think.
I chose to write this article because we live in the social media era. I was constantly busy, especially on Facebook, making the same point every time: "Creatine doesn't make your muscles bigger," which can be translated into an even clearer language: "Creatine doesn't have any anabolic properties."
Before I start our discussion we need to address a few important concepts to clarify the general picture. To understand and make the point clearer, it is important to understand the entire environment in which the subject matter is located. I will take the argument from a distance and slowly bring it closer for you to properly understand the question.
Anabolic and Catabolic
We are talking about the skeletal muscle system, so at the moment, we are discussing the catabolic and anabolic processes in this specific body system. We are specifically talking about the process related to the development of the muscle and the way it works.
The anabolic process in this case mostly relates to the ratio at which the muscle cells synthesize new proteins that are used to repair damaged muscle fibers or strengthen them. The catabolic process, on the other hand, involves the opposite, where proteins are depleted from the muscle fibers.
Even though this may not be intuitive, it is important to understand that both processes are running simultaneously. Proteins are also used as an alternative source of energy when other macronutrients are not available. There are also important processes of cellular renewal, where some cells die and need to be replaced by new ones.
If you think about a company's business year, the performance of the company is represented by a graph. The graph sometimes goes up and sometimes goes down. There is normally another line that crosses the line on the graph, which can be steady, growing, or declining. That line is called a trend. That line shows you if the company is doing well or poorly.
The catabolic and anabolic processes can be seen as the line that goes up (anabolic) and the line that goes down (catabolic). The trend of the line tells us if we have a stronger anabolic process or a stronger catabolic process.
In summary, if we are gaining muscles or losing muscle.
Steroids and Anabolic steroids
Many times you may come across the term "anabolic steroids". We don't need to know what steroids are in this discussion. We just need to know that they are molecules with a defined chemical composition, dimension, and structure. They are essential molecules that promote a cellular response. In our case, that response is an increased expression of protein synthesis. When you are training, for example, you are causing damage to the muscle tissue. The information regarding this damage is received by the brain and processed by the same. As a result, the brain transmits the information to the relevant endocrine glands that interact with the relevant organs (in this case, kidneys and gonads) to increase the production of a specific molecular signal (in this case, steroids) that promotes protein synthesis.
The cells of the muscle tissue have receptors for these steroids, which are designed to interact specifically with that molecule. They have a binding site and a specific affinity for the chemical composition of that molecule, and the binding site is designed to accommodate that particular molecule.
When this occurs, a cascade of phenomena occurs at a nuclear level, promoting the reparation of the damaged muscle. Building muscles is expensive in terms of resources, so to avoid this happening again, the size and strength of the muscle are increased. Essentially, the same stress that damaged the muscle can happen again, so the whole tissue is pre-emptive to strengthen the muscle so next time the stress will be addressed sufficiently.
This mechanism is called "super-compensation." This is the main reason why training must involve "progressive overload" and must be maintained. Otherwise, the catabolic process takes over and reduces the muscle to the level of the current stress experienced. Muscle tissue must be maintained, and this costs resources, so it is pointless to keep a hypertropic muscle if is not needed. We are machines made to survive, so biological economy is very important. Our body doesn't like to use resources if it is not necessary.
As you can see from this oversimplified description, the entire metabolism of muscle tissue is finely regulated. What exogenous or synthetic steroids do is bypass all the reasons why that expression (of protein) occurs, essentially forcing the muscle tissue to produce protein and increase in size regardless.
Creatine
It`s a part of a complex group of reactions related to energy production and usage. Compared to steroids, Creatine has a different chemical structure, size, and function. It doesn't interact with the steroid receptor, is not produced in the gonads, but is assimilated through the diet and a small amount is produced daily, especially in the liver and to a lesser extent in the pancreas and kidneys.
Creatine is a crucial aspect in the way muscle cells fuel muscle contraction during exercise and daily activity. To discuss the role of creatine, we must discuss the “energy systems”. However, how muscle contraction is obtained through the consumption of an array of different molecules. Primarily, these molecules are fat, protein, and carbohydrates.
These molecules are stored in different body districts: Some are stored in the place or surroundings on which their utilization occurs, and others are stoked on specialized structures or organs. In the muscle cells, we have some fat, free amino acids, and the main resource of energy for the contraction of the muscle in the form of glycogen (which are essential storage of packed carbohydrates).
In the bloodstream, we have blood glucose (carbohydrates) and some fat in the form of triglycerides. We have also tissues and organs that store these sources of energy. The liver has the largest (relatively) store of glycogen, while adipose tissue has the largest store of fat.
Insulin and Glucagon
The level of glucose in the blood is under strict control. When the level of glucose is too high, insulin captures these molecules and sends them to be processed in the liver to produce glycogen stores or in the adipose tissue to be processed as fat.
As opposed to glucagon, which does exactly the opposite, when glucose levels decrease, it forces the depletion of stored glycogen to increase glucose levels.
The entire process is aimed at maintaining blood sugar concentration and is called homeostasis. What we see here is a logistic chain. The liver and adipose tissue send macronutrients through the bloodstream to replenish cells that are running low on energy.
The energy process inside the cells of skeletal muscles is primarily fueled by glucose and fat. To a lesser extent, it can also be fueled by protein (or more specifically, its constituent amino acids).
The energy system
The main processes to create energy are located in the cytosol (an internal portion of the cell) through a reaction called glycolysis, and in specialized internal organelles called mitochondria, in a process called oxidative phosphorylation.
How this process is conducted largely depends on the pathway the fuel storage takes. The mitochondrial pathway relies on relatively large amounts of stored energy (especially fat) and has the most production of energy in the long term, as it can completely utilize glucose and its byproducts, as well as the energy-rich chain of fatty acids. However, it is slow and strongly dependent on oxygen to function. This is why it is also called the aerobic system.
The glycolytic system relies on the partial breakdown of a glucose molecule with the production of two byproducts that are not interesting for our discussion. This releases much less energy compared to the one that originates in the mitochondria. However, it is fast and does not depend on oxygen. For that reason, it is also called anaerobic.
What is important to understand is the difference between the source of fuel and the speed at which this is processed. So basically, we have a small amount of energy that is available for a long period, and an average to high amount of energy that is available for a medium and for a short period. This translates into an energy system that can provide energy for a medium effort for a medium period, an energy system that can provide energy for a small effort over a large period, and an energy system that can provide energy for high effort for a short period.
We also need to point out that all these systems don't switch from one to another, but they work together all the time; it's just that one is more predominant in different scenarios. For example, if someone is used to operating a caloric counter app, the basal metabolism or rest energy expenditure is around 1400 to 1600 kcal, depending on different factors. So, the amount of daily energy that the body uses just to be alive is used for respiration, cell regeneration, and other organs and tissue maintenance and function. That energy is the biggest daily energy expenditure and is provided largely by mitochondria.
Summarizing
Aerobic system: slow speed, large capacity, duration above 2 min. Fuel: Fat, glucose, protein, glycogen.
Anaerobic system: fast speed, medium capacity, duration 10 sec-2 min. Fuel: Glucose and glycogen.
CP (creatine phosphate system): Very fast speed, low capacity, duration less than 10 sec. Fuel: ATP, Phosphocreatine.
The role of ATP and CrP.
Every single chemical reaction in the body is led by a singular molecule, usually working together with a class of proteins called "enzymes". Enzymes process a wide variety of chemical reactions. For example, they can break the union of two specific molecules or fuse two different molecules. In the case of skeletal muscle, we have two series of protein chains called myosin and actin. They slide together on opposite sides of each other. For every movement of these two chains, chemical bonds are formed and broken. The coordinated and sequential movement of these two filaments, which are the basic units in a muscle fiber, is the reason why the muscle extends or contracts.
The energy for these reactions to happen is stored in the bond between adenosine and one or more phosphate atoms. The well-known molecule is called ATP or adenosine triphosphate. Basically, in a reaction controlled by an enzyme, the ATP loses one phosphate atom, and the energy that was used to keep the phosphate bound to the adenosine is released and can be used to form another product. That's it.
So in the cell, we constantly have two forms of this molecule, the charged one (ATP) and the depleted one (ADP). The charging of this molecule occurs in the cytosol (glycolysis) or the mitochondria (oxidative phosphorylation).
The stock of ATP is very limited in the cells and can provide energy for the muscles to work for just a couple of seconds. Another molecule that fixes this problem, present in much larger quantities, has the property to recharge the depleted ADP to ATP and maintain the muscles at work. Furthermore, it also increases the speed at which new ATP is formed. This molecule is called Creatine and is loaded with a phosphate atom.
Creatine phosphate is a ready-to-use reserve energy for ATP reformation. It's like we have a battery. When maximum effort is exerted, the ATP is used and recharged at the same time by the CrP. The work continues at this intensity as long as we have charged creatine stock.
Creatine stock lasts for about 10 seconds. After this point, the muscles are not able to keep the same level of exertion. The full replenishment of creatine stock takes about 5 minutes or more (at rest). However, the muscles are capable of working because of the action of the anaerobic and aerobic systems, which are recharging ATP and CrP.
When glycolysis reaches its natural limit and cannot process glucose and glycogen at that pace, the muscle action has to rely predominantly on the aerobic system (the slowest).
Creatin usage and his benefit
Based on the level of muscle engagement we have high intensity, moderate intensity, and low intensity. In most sports, all elements are present, or a combination of them; a soccer player alternates moments of sprinting with moments of low running or jogging, for example.
The supplementation of creatine works to increase the stock of intracellular creatine, and therefore, increases the size of the “battery”. Such supplementation is extremely useful in almost the vast majority of sports, especially in high-intensity sports like powerlifting, running, etc.
There is a growing number of scientific evidence about the different benefits of creatine in other clinical aspects, especially for elderly people. Some studies also suggest that creatine supplementation slightly increases lean muscle mass.
My favorite source of information about supplements, Examine.com, is an aggregator of scientific studies and shows the relevance of each proclaimed benefit by the number of studies conducted and the number of people participating in the trials.
In a scientific environment, the more studies that are done on an area of interest, the more participants are involved in the scientific trials to investigate the discussion of that study and the more weight the study carries in the scientific debate. It is also important to note that the number of citations a study has in other scientific papers increases its weight as well.
The property of creatine that is most observed and largely evident is also confirmed by the vast majority of studies conducted with the largest number of participants in the relative trials. And all of them announce the same thing:
Power Output
McCarthy JJ, Esser KA. Anabolic and catabolic pathways regulating skeletal muscle mass. Curr Opin Clin Nutr Metab Care. 2010 May;13(3):230-5. doi: 10.1097/MCO.0b013e32833781b5. PMID: 20154608; PMCID: PMC2877703.
Attwaters M, Hughes SM. Cellular and molecular pathways controlling muscle size in response to exercise. FEBS J. 2022 Mar;289(6):1428-1456. doi: 10.1111/febs.15820. Epub 2021 Mar 29. PMID: 33755332.
Antonio J, Candow DG, Forbes SC, Gualano B, Jagim AR, Kreider RB, Rawson ES, Smith-Ryan AE, VanDusseldorp TA, Willoughby DS, Ziegenfuss TN. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr. 2021 Feb 8;18(1):13. doi: 10.1186/s12970-021-00412-w. PMID: 33557850; PMCID: PMC7871530.
Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? - PMC (nih.gov)
Baker, Julien S., McCormick, Marie Clare, Robergs, Robert A., Interaction among Skeletal Muscle Metabolic Energy Systems during Intense Exercise, Journal of Nutrition and Metabolism, 2010, 905612, 13 pages, 2010.
Kreider, R.B., Kalman, D.S., Antonio, J. et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr 14, 18 (2017).
International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine | Journal of the International Society of Sports Nutrition | Full Text (biomedcentral.com)
Alghannam AF, Ghaith MM, Alhussain MH. Regulation of Energy Substrate Metabolism in Endurance Exercise. Int J Environ Res Public Health. 2021 May 7;18(9):4963. doi: 10.3390/ijerph18094963. PMID: 34066984; PMCID: PMC8124511.
Wallimann T, Tokarska-Schlattner M, Schlattner U. The creatine kinase system and pleiotropic effects of creatine. Amino Acids. 2011 May;40(5):1271-96. doi: 10.1007/s00726-011-0877-3. Epub 2011 Mar 30. PMID: 21448658; PMCID: PMC3080659.
Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. The Mitochondrion.
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