what is creatine?

Introduction

Creatine is a naturally occurring compound synthesised in the body from the amino acids arginine, glycine, and methionine. It is predominantly stored in skeletal muscle, with ~95% of the body’s creatine reserves found in muscle tissue (Buford et al., 2007; Kreider & Jung, 2011), primarily in the form of phosphocreatine. Phosphocreatine serves as a high-energy phosphate reservoir that helps regenerate adenosine triphosphate (ATP); the main energy currency of the body.

During high-intensity, short-duration activities or explosive movements, the body relies on ATP for quick energy. Creatine supports this process by donating a phosphate group to adenosine diphosphate (ADP), converting it back into ATP and thus enabling continued high-power output in muscles. The availability of intramuscular creatine and phosphocreatine is essential for sustaining peak performance in activities that require bursts of power or speed.

Supplementation with creatine increases the body’s stores of intramuscular creatine and phosphocreatine, enhancing an individual’s ability to perform during exercise (Crisafulli et al., 2018). This is particularly beneficial for athletes involved in strength training, explosive sports, and events requiring intermittent high-intensity efforts. Creatine monohydrate remains one of the most commonly researched supplements globally.

 

Creatine's impact on athletic performance

Creatine has been widely documented in the literature as an ergogenic aid (Kreider et al., 2017). Creatine acts by enhancing the body's ability to rapidly regenerate ATP, the primary energy source for muscle contractions. During high-intensity exercise, ATP is quickly depleted, and creatine, stored as phosphocreatine in muscle cells, donates a phosphate group to regenerate ATP.

This process allows athletes to sustain high-intensity and explosive movements for longer durations before fatigue sets in. By increasing phosphocreatine availability, creatine supplementation has been shown to improve strength, power output, and overall exercise performance (Wax et al., 2021).

Beyond energy production, creatine also supports muscle growth and recovery (Wax et al., 2021). It enhances cellular hydration by drawing water into muscle cells, promoting an anabolic environment for muscle protein synthesis.

Additionally, creatine supplementation has been shown to reduce muscle damage, inflammation, and oxidative stress post-exercise, leading to faster recovery (Wax et al., 2021). These combined effects make creatine one of the most well-researched and effective supplements for improving athletic performance, particularly in strength and power-based sports.

 

Impact on general health  

Beyond its ergogenic effects, creatine plays a vital role in brain health by supporting cognitive function and protecting against neurological decline (Xu et al., 2024). The brain requires large amounts of energy to sustain processes like memory, learning, and problem-solving, relying on ATP as its primary fuel source. Creatine helps maintain ATP production by serving as a rapid energy reservoir through its stored form, phosphocreatine.

This is particularly beneficial during periods of mental fatigue, sleep deprivation, or cognitive stress (Candow et al., 2023). Research has shown that creatine supplementation can enhance cognitive performance, particularly in tasks requiring short-term memory, reasoning, and processing speed (Avgerinos et al., 2019).

Beyond its role in energy metabolism, creatine has neuroprotective effects. It helps stabilise cellular energy balance, reducing oxidative stress and inflammation (Sztemberg et al., 2024) - both of which are linked to neurodegenerative diseases like Alzheimer’s and Parkinson’s. Additionally, creatine may influence neurotransmitter function, potentially alleviating mental fatigue (Wantanabe et al., 2002). These findings suggest that creatine supplementation is not only valuable for athletic performance but may also serve as a practical strategy for preserving brain health and cognitive function across various populations.

 

Creatine intake recommendations  

As we can see above, creatine supplementation is well-documented for its benefits in enhancing exercise performance, recovery, and muscle mass. Traditionally, a creatine loading phase involves taking 20 g/day, divided into four doses, for 5-7 days, followed by a maintenance phase of 3-5 g/day to sustain creatine levels in the muscles. This loading phase helps saturate muscle stores quickly.

However, there is an array of recent research that suggests that skipping the loading phase and starting with 3-5 g/day can still achieve muscle saturation over a period of ~28 days (Antonio et al., 2021), making the process simpler for many people. Creatine monohydrate remains the most extensively researched and effective form, with long-term supplementation at recommended doses proving to be safe, with no adverse effects on renal function in healthy individuals.

 

Dietary sources of creatine 

Creatine is naturally found in animal-based foods, particularly in red meat and fish, which are the richest dietary sources. While this contributes to overall creatine intake, it is generally not enough to achieve the higher doses typically used for performance or cognitive benefits, which are around 3-5 grams daily.

To reach these optimal levels through diet alone would require consuming large quantities of meat or fish daily, which may not be practical or sustainable for many. This is why creatine supplementation has become so popular - it offers a convenient and effective way to ensure individuals can reach and maintain optimal intramuscular creatine levels without the need for excessive food intake. By supplementing with creatine, athletes and individuals seeking cognitive or health benefits can more easily enhance their performance, recovery, and overall well-being.