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The effects of creatine

Une scoop de créatine avec en arrière plan un mètre souple ainsi qu'un poids de musculation
Creatine is one of the most popular and well-studied dietary supplements in the world.

Creatine is one of the most popular and widely studied sports supplements in the world. Primarily used by athletes and bodybuilders, it is renowned for its ability to improve physical performance and promote muscle mass gain. Here, we will examine the various effects of creatine, based on scientific studies and athlete testimonials. We will explore what creatine is, how it works, its dietary sources, the benefits of supplementation, and best practices for its use.

What is Creatine?

Creatine is an organic compound derived from amino acids, specifically arginine, glycine, and methionine. It is naturally present in the human body, where it plays a central role in muscle energy metabolism.

The majority of creatine in the body, approximately 95%, is stored in skeletal muscles as phosphocreatine.

Creatine Synthesis and Function

Creatine synthesis begins in the kidneys with arginine and glycine, which react to form guanidinoacetate. This compound is then transported to the liver, where it is methylated to produce creatine. Creatine is then released into the blood and transported to the muscles, where it is phosphorylated to form phosphocreatine. Phosphocreatine is a rapid energy reserve. During intense and short-duration physical efforts, such as sprinting or weightlifting, muscle ATP (adenosine triphosphate) reserves are quickly depleted. ATP is the main energy molecule in cells, but it cannot be stored in large quantities. Phosphocreatine then intervenes to replenish ATP by providing a phosphate group, thus allowing muscles to continue producing energy quickly and efficiently.

Creatine Metabolism

Creatine metabolism in the body is a continuous process. Approximately 1 to 2% of the total body creatine is degraded daily into creatinine, a metabolic waste product that is excreted by the kidneys in urine. This means that the body needs to constantly replenish its creatine reserves, either through endogenous synthesis or dietary intake.

Dietary Sources of Creatine

In addition to endogenous synthesis, creatine is also obtained from diet. The main dietary sources of creatine are animal products, such as red meat and fish. For example, herring, beef, and salmon are rich in creatine, making them valuable foods for people who do not take creatine supplements.

Creatine Transport and Absorption

Creatine transport into muscle cells is mediated by a specific transporter, the creatine transporter (CRT). This transporter is regulated by various factors, including the availability of creatine in the blood and cellular energy levels.

When creatine reserves are low, the activity of the creatine transporter increases to maximize creatine absorption and storage in muscles.

Ergogenic Benefits of Creatine

Creatine's ability to increase phosphocreatine reserves in muscles makes it a powerful ergogenic sports supplement for athletes and bodybuilders.

By increasing phosphocreatine levels, creatine enables faster and more sustained ATP production, which improves performance during intense and short-duration efforts. This translates into increased strength, power, and muscular endurance, as well as faster recovery between exercise sets.

Creatine Beyond Muscles

Although most creatine is stored in skeletal muscles, it is also present in other tissues, including the brain and heart. In the brain, creatine acts on neuronal energy metabolism, which may have implications for cognitive functions. In the heart, creatine contributes to the efficiency of the heart muscle, although its exact effects are still under investigation.

Dietary Sources of Creatine

Creatine is naturally found in several foods, mainly in animal products such as meat and fish. For example, one kilogram of red meat contains approximately 5 grams of creatine. Dietary sources of creatine include:

  • Beef: 4.5 g/kg
  • Pork: 5 g/kg
  • Herring: 6.5 g/kg
  • Salmon: 4.5 g/kg
  • Tuna: 4 g/kg
  • Cod: 3 g/kg

Plant sources contain very little creatine, which is why vegetarians and vegans can greatly benefit from creatine supplementation to reach optimal levels.

Why Take Creatine Powder?

Although creatine is present in food, it is difficult to consume enough through diet alone to maximize its ergogenic effects. For example, to obtain a dose of 5 grams of creatine, one would have to consume approximately one kilogram of red meat, which is neither practical, economical, nor ecological.

Sports supplements are thus a flexible and effective solution for increasing creatine levels in the body.

Benefits of Creatine for Athletes

Improved Physical Performance

One of the main effects of creatine is the improvement of physical performance, particularly in sports requiring intense and short-duration efforts.

Studies show that creatine supplementation can increase maximum power and strength by 5 to 15%. This allows athletes to train more intensely, perform more repetitions, and recover faster.

Increased Muscle Mass

Creatine also contributes to increased muscle mass. Studies report gains of 0.5 to 1.6 kilograms during the first two weeks of a creatine cycle. These gains are primarily due to water retention in the muscles. In the long term, creatine promotes muscle growth by increasing the muscles' ability to perform more intense exercises.

Effects on Strength and Endurance

Creatine acts on muscle strength and endurance by increasing the available ATP levels in muscles. This helps delay muscle fatigue and prolong effort duration. Athletes can thus achieve superior performance during training and competitions.

By increasing available ATP levels in muscles, creatine delays muscle fatigue and prolongs effort duration. Studies show that creatine supplementation can increase maximum power and muscle strength by 5 to 15%, particularly beneficial for sports requiring explosive efforts such as weightlifting, sprinting, and combat sports. By enhancing ATP regeneration, creatine helps maintain high performance during intense exercise and promotes faster recovery between sets, thus allowing for more frequent and intense training.

Creatine also improves anaerobic endurance, allowing for the repetition of intense efforts with less recovery time, which is essential in sports like football and basketball. By facilitating muscle recovery, it reduces post-exercise soreness and inflammation, thereby allowing for faster return to training.

When to Take Creatine?

What constitutes the ideal time to take creatine is a subject of debate among experts. However, studies suggest that taking creatine immediately after training may offer better results in terms of lean mass gain.

Creatine can thus be mixed with a post-workout snack, often composed of protein and carbohydrates, to improve its absorption.

Recommended Daily Dose

For a long time, a loading phase of 20 grams of creatine per day for five days was recommended, followed by a maintenance phase of 5 grams per day.

However, studies show that taking 3 to 5 grams per day without a loading phase can be just as effective in the long term. A lower dose also reduces the risk of digestive issues and organ overload.

Creatine: Before or After Training?

It is generally recommended to take creatine after training to maximize muscle gains. However, some athletes prefer to split their daily dose into several intakes throughout the day. This method can improve the absorption and utilization of creatine by the muscles.

When considering when to take creatine, it is important to note that taking small doses throughout the day can maintain more stable creatine levels and promote better muscle saturation.

Why Take Creatine Breaks?

Whether to cycle creatine intake or take it continuously is also a debated topic. Some athletes opt for two-month cycles followed by a month off to avoid gain stagnation. Others prefer continuous intake, adjusting their consumption according to their training intensity.

Taking a break allows the body to restart its natural creatine synthesis and prevent potential tolerance.

Combining Creatine with Other Supplements

Creatine and Whey Protein

The combination of creatine and whey protein is particularly recommended for bodybuilders. Creatine enables more intense workouts, while whey protein provides the amino acids necessary for recovery and muscle growth.

Taking these two supplements together after training maximizes their synergistic effects.

Creatine and BCAAs

BCAAs (branched-chain amino acids) are often used around training sessions to improve recovery and reduce muscle breakdown. They can be combined with creatine to optimize performance and muscle growth.

However, priority should be given to a balanced diet and sufficient protein intake.

Creatine and Glutamine

Glutamine is another popular supplement among athletes. It is known for its effects on protein synthesis and recovery. While creatine and glutamine can be taken together, it is important to note that their mechanisms of action are different.

Creatine is primarily used to improve performance and strength, while glutamine promotes recovery and intestinal health.

Creatine Side Effects

Creatine is generally well-tolerated by most users when taken in recommended doses. Potential side effects include cramps, headaches, and digestive issues, mainly when consumed in large quantities.

It is essential to drink enough water to avoid dehydration, especially during intense efforts or in hot weather.

Creatine and Kidney Function

Some concerns have been raised regarding the impact of creatine on kidney function. However, most studies have found no solid evidence that creatine damages the kidneys in healthy individuals.

Nevertheless, it is recommended for individuals with a history of kidney problems to consult a healthcare professional before starting creatine supplementation.

Other Potential Side Effects

Other potential side effects of creatine include weight gain due to water retention and muscle soreness.

These effects are generally temporary and diminish over time. It is important to follow dosage recommendations to minimize these risks.

Creatine and Cognitive Performance

While creatine is primarily known for its effects on physical performance, recent research suggests that it may also have beneficial effects on cognitive functions.

Studies have shown that creatine could improve memory, concentration, and intellectual abilities by increasing ATP availability in the brain. These effects are particularly interesting for students and professionals seeking to enhance their mental performance.

Creatine in Endurance Sports

Although creatine is often associated with strength and power sports, it can also be beneficial for athletes engaged in endurance sports. Creatine can help improve performance by increasing phosphocreatine reserves in muscles, which allows for faster recovery between intense efforts.

Endurance athletes can thus benefit from improved fatigue resistance and faster recovery.

Creatine and Body Composition

One of the remarkable effects of creatine is its impact on body composition. By increasing muscle mass and reducing body fat, creatine can help athletes improve their physique and performance. Studies have shown that creatine supplementation can lead to a significant increase in lean muscle mass and a reduction in body fat, especially when combined with an appropriate training program.

Creatine and Bone Health

Recent research suggests that creatine could also have beneficial effects on bone health. It has been shown that creatine supplementation can increase bone mineral density and improve bone strength.

These effects are particularly interesting for athletes and older adults seeking to prevent fractures and bone injuries.

Creatine and Neuromuscular Adaptations

Creatine can also influence neuromuscular adaptations to training. By increasing ATP availability in muscles, creatine allows for faster and more efficient muscle activation.

This can lead to improved sports performance and a reduced risk of injuries.

Creatine is therefore a widely recognized supplement for its numerous beneficial effects on physical performance and muscle growth. By increasing ATP levels in muscles, it allows for more intense workouts, better recovery, and significant muscle gains.

Although creatine is present in some foods, supplementation remains the most effective way to achieve optimal levels. To maximize the benefits of creatine, it is essential to follow recommended doses and combine it with a balanced diet and an appropriate training program. 

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