Creatine as a performance enhancing supplement has received support from the Journal of the International Society of Sports Nutrition, and in joint position stands from the American College of Sports Medicine, Academy of Nutrition and Dietetics, and Dietitians in Canada. Creatine use can increase maximum power and performance in high-intensity anaerobic repetitive work (periods of work and rest) by 5 to 15%. Creatine has no significant effect on aerobic endurance, though it will increase power during short sessions of high-intensity aerobic exercise.
An approximation of 0.3 g/kg/day divided into 4 equal spaced intervals has been suggested since creatine needs may vary based on body weight. It has also been shown that taking a lower dose of 3 grams a day for 28 days can also increase total muscle creatine storage to the same amount as the rapid loading dose of 20 g/day for 6 days. However, a 28 day loading phase does not allow for ergogenic benefits of creatine supplementation to be realized until fully saturated muscle storage.
This elevation in muscle creatine storage has been correlated with ergogenic benefits discussed in the therapeutic uses section. However, higher doses for longer periods of time are being studied to offset creatine synthesis deficiencies and mitigating diseases.
After the 5–7 day loading phase, muscle creatine stores are fully saturated and supplementation only needs to cover the amount of creatine broken down per day. This maintenance dose was originally reported to be around 2–3 g/day (or 0.03 g/kg/day), however, recent studies have suggested 3–5 g/day maintenance dose to maintain saturated muscle creatine.