Creatine is one of the most popular sports supplements, and the reason may be that it improves high-intensity athletic performance after taking it. When our athletic performance improves, we can achieve greater training adaptation and improve our functional state. Phosphate is ubiquitous in all species and plays an important role in maintaining energy availability. The main metabolic effect of creatine is the enzymatic reaction of creatine kinase (CK) binding to phosphoryl groups (Pi) to form phosphocreatine (PCr). The pleiotropic nature of creatine is mainly related to the function of CK and PCr (i.e., the CK/PCr system). Since adenosine triphosphate (ATP) is degraded to adenosine diphosphate (ADP) and Pi provides free energy for metabolic activities, the free energy released by PCr hydrolysis into Cr+Pi can be used as a buffer for ATP resynthesis. This helps maintain ATP availability, especially during anaerobic sprint exercise. This is one of the reasons why we can improve our performance in high-intensity sports after creatine supplementation.

Potential enhancement of creatine supplementation • Improves performance in single and repetitive sprints • Increases workload during maximal effort muscle contractions • Increases muscle mass and strength fitness during training • Enhances glycogen synthesis • Increases anaerobic threshold • Increases aerobic capacity through more shuttle of ATP in the mitochondria • Improves exercise capacity • Enhances recovery • Improves training tolerance

1. How to supplement creatine

Our normal daily diet contains about 1-2 grams of creatine, in which case muscle creatine stores about 60-80% of the maximum store. The literature notes that the most effective way to increase muscle creatine stores is to consume 5 grams of creatine (or about 0.3 g/kg body weight) four times a day for 5-7 days. Once intramuscular creatine stores are fully saturated, creatine stores can be maintained by consuming 3-5 grams per day, and some studies suggest that larger athletes may need to consume 5-10 grams per day to maintain creatine stores. These two stages are also commonly referred to as the "shock period" and the "maintenance period". But does it necessarily need a "shock period"? A common misconception about creatine supplements is that creatine stores must be increased in the muscles through a "shock period" before they can experience the powerful benefits of creatine supplements. However, studies have shown that a strategy of lower daily creatine supplementation (i.e., 3-5 g/day) can increase intramuscular creatine stores, resulting in greater improvements in muscle mass, athletic performance, and recovery. However, creatine supplementation without a "loading phase", i.e., higher "loading" doses, delays the time for intramuscular creatine to reach its maximum storage (study data indicate similar accumulation of creatine in muscle in subjects who consumed 3 grams per day for 28 days or 20 grams per day for 6 consecutive days). Determining which way to take creatine depends on the individual's goals. For example, if you want to maximize the benefits of creatine supplementation in a short period of time (<30 days), a creatine "shock" strategy may be more appropriate. However, if creatine intake is planned over a longer period of time (>30 days) or to avoid the potential weight gain that sometimes occurs during creatine "loading," creatine "maintenance" strategies are a more reasonable option.

2. Is creatine only useful for strength training?

Although creatine supplementation is theoretically beneficial primarily for participation in high-intensity intermittent resistance/strength-type activities, there is growing evidence that creatine supplementation may also provide beneficial effects on other activities. Data suggest that supplementation with carbohydrates or carbohydrates and protein at the same time promotes more muscle glycogen storage than carbohydrate supplementation alone. Because glycogen supplementation is important to promote recovery and prevent overtraining during intensive training, creatine supplementation can help athletes who consume large amounts of glycogen during training and/or competition to maintain optimal glycogen levels. In addition, creatine supplementation during exercise-induced muscle injury recovery can reduce muscle damage and better maintain muscle performance.

Examples of benefits of creatine supplementation for different sports

1. Increase PCr: Athletics sprint: 60–200 m, Swim sprint: 50 m
2. Add PCr resynthesis: basketball, American football, ice hockey, volleyball
3. Reduce muscle acidosis: alpine skiing, water sports (e.g., rowing, kayaking), swimming: 100, 200 m, track and field: 400, 800 m, combat sports
4. Oxidative metabolism: interval training for basketball, football, tennis, and endurance athletes
5. Gain weight/muscle mass: bodybuilding, combat sports, weightlifting, rugby, track and field events (throwing the heavy metal bal, javelin, discus, etc.).

3. Is it safe to take creatine?

Creatine is a popular sports nutrition supplement used by many athletes and fitness enthusiasts to improve athletic performance and increase muscle mass and strength. But many people still have concerns about the safety of taking creatine. For example, creatine supplementation can cause kidney damage.

In some clinical trials of creatine supplementation, markers of kidney health, inflammation, and liver function were continuously monitored, none of which were negatively affected by the corresponding creatine supplementation intervention. In addition, a review of the safety of adolescent creatine supplementation noted the effectiveness of creatine supplementation in a variety of adolescent athlete populations, and no evidence of adverse effects was found. And short- and long-term studies in healthy and diseased populations, from infants to the elderly, have shown that creatine intake at doses of 0.3-0.8 g/kg* body weight per day, creatine does not pose adverse health risks and may provide many benefits for athletic performance and health. And there is growing evidence to support that creatine can improve the health of individuals as they age. For example, creatine helps lower cholesterol and triglyceride levels, reduce liver fat accumulation, enhance blood sugar control, and increase strength and/or muscle mass.

In fact, there has been more than 20 years of research on creatine, and the U.S. Food and Drug Administration (FDA) classified creatine as generally recognized as safe in 2020. This classification indicates that the currently available scientific data on creatine safety are sufficient and have been agreed upon by experts.

4. Does creatine increase fat mass?

For most sports enthusiasts, they are worried that creatine intake will cause fat gain. The reason for this concern may be that some people gain weight through creatine supplementation. However, many studies have shown that creatine supplementation does not increase fat mass, and some studies have also found that creatine supplementation increases lean body mass. In a systematic review and meta-analysis of 19 studies with a total of 609 participants, it was shown that participants who supplemented with creatine lost about 0.5 kg of fat and had a significant reduction in body fat percentage compared to the placebo supplementation group. The results of the study suggest that creatine supplementation does not increase fat mass in various populations.