What is Creatine?
Creatine is a substance that is found naturally in the human body and plays an important role in energy metabolism. It helps restore the energy deposits of the body, especially in the muscle tissue, during times of physical or mental activity. Foods rich in creatine and creatine supplements are popular among body builders, sports enthusiasts and people who want to increase their muscle mass, enhance their endurance and improve their mental abilities. Creatine is often conveniently added to whey protein supplements.
The story of creatine supplements started in 1912, when Otto Folin and Willey Glover Denis, two scientists from Harvard University, discovered that a high creatine intake leads to higher creatine content in the muscles. Since then many famous athletes and body builders have followed a high-creatine dietary program or have taken creatine powder to improve their performance. Because creatine is a natural substance that can be produced in the human body or can be supplied through eating large quantities of meat, it is not considered an illegal substance or "dope" for athletes.
How Does Creatine Work in a Typical Muscle Cell?
For a better understanding of how creatine can improve performance and its health benefits, it is useful to explain creatine’s "mechanism of action" at the cellular level.
All processes that take place in the human body require energy consumption, including muscle contraction, protein synthesis, producing hormones, transmitting nervous impulses and maintaining a constant body temperature.
The Energy Currency of the Body
Muscle contraction is the most energy consumptive process in the human body. ATP, short for Adenosine Triphosphate, is the molecule that supplies energy for muscle contraction. When ATP transforms into ADP (Adenosine Diphosphate), a certain amount of energy is released and this is used to fuel the muscular activity. So ATP is considered an energy storage molecule and is sometimes called "the energy currency of the body."
The muscle proteins that execute the contraction need a continuous supply of ATP to remain functional. However, the muscle reserves of ATP are very insignificant. The stored ATP can be used for only several muscle contractions lasting a few seconds until becoming depleted. Fortunately, there are biological systems that continuously replenish the ATP reserves by facilitating the recovery of ATP from ADP. One of them is called the Creatine Kinase system and creatine is an essential component of it.
Creatine is produced in the kidneys and in the liver from several amino acids that are readily available in the body. It is then transferred into the bloodstream and transported to the tissues that have high energy expenditure. Muscle tissue is by far the largest consumer of creatine. Creatine is captured and introduced into the muscle cells where it enters in the Creatine Kinase enzyme cycle. Precisely, Creatine Kinase transfers the energy stored in the molecular structure of creatine into the chemical reaction that restores the ATP molecule from the low-energy ADP molecule. With ATP being continuously consumed during muscle contraction, a steady supply of creatine is needed to maintain the energetic balance of the muscle tissue.
Scientists have observed that the amount of creatine in the muscles is directly proportional to the maximum strength and endurance of muscle contractions. More creatine in the muscles means more energy for muscle contraction, which translates into more powerful and prolonged muscle work. Athletes and body builders who want to stay competitive in their sports frequently follow a creatine-rich diet or take creatine powder or capsules to increase the amount of energy stored in their muscles, enabling them to achieve a higher performance level.
What Are the Benefits of a High Creatine Intake?
The main benefit of a high creatine intake is the increased amount of energy available for a stronger and longer training session. However there are other creatine benefits as well:
Increased Muscle Volume
About 95 percent of the creatine available in the bloodstream is incorporated into the muscles. Besides providing more energy, creatine increases the volume of the muscles and their hydration. The muscles look bigger and their energetic deposits are larger. Additionally, when incorporated in the muscle cells, creatine draws in a significant amount of water, which further increases the muscle cell volume.
Enhanced Protein Synthesis & Enlarged Muscle Fibres
By increasing energy deposits, creatine accelerates and facilitates protein synthesis and increases carbohydrate deposits in muscle tissue. Enhanced muscle protein production leads to muscular hypertrophy, which is a process that involves enlarging individual muscle fibres.
Greater Endurance
Besides replenishing the short-term ATP deposits, creatine helps create additional long-term carbohydrate resources in the form of glycogen deposits. This is how creatine stimulates prolonged muscle contraction and endurance. This is essential for long-distance running, swimming and other types of physical activity where maintaining a certain intensity of muscular contraction over a long period of time is needed.
Enhanced Anabolic Hormone Production
Several research studies have confirmed that creatine facilitates the production of anabolic hormones. These are highly potent biological molecules that strongly stimulate muscular tissue growth and muscle fibre enlargement. Anabolic hormones have a similar structure to the male sexual hormone testosterone. They work by enhancing the incorporation of amino acids into new proteins in the muscles. Creatine monohydrate intake also increases the production of insulin-like growth factor (IGF), which also has powerful anabolic muscular effects and increases protein synthesis.
It is important to understand that creatine is not a substitute for intense training or a healthy diet, which are vital for proper muscle growth.
What Foods are Rich in Creatine?
Creatine is found in all animals because it performs the same functions regardless of the species. About 95 percent of creatine is contained in the muscles, with small quantities being found in the brain and other organs. This is why the most significant sources of natural creatine are in high protein foods like lean meat and fish. Other foods contain very small amount of creatine, and vegetarian food does not contain creatine at all. The amount of creatine in one pound of meat or fish ranges between one and two grams. When starting a high-creatine diet for muscle building purposes, it is best to choose low-fat meat or fish because it has the highest creatine content.
However, for competitive body builders, the amount of creatine provided by food is usually insufficient, and they need to take creatine supplements to provide a steady supply to their muscles.