Heart Disease 8. However, outcomes for trained athletes in competitive situations have not been consistent. 14 Creatine supplementation does not appear to increase endurance performance and may impair it by contributing to weight gain. 15 Improvements in exercise performance after creatine supplementation are strongly dependent on the extent of muscle retention of creatine during supplementation. Creatine supplementation has been reported to improve strength in rare diseases of muscle and energy metabolism.
Creatine is produced naturally in the human liver, pancreas, and kidneys.
It is concentrated primarily in muscle tissues, including the heart. Supplements in the form of creatine monohydrate are well absorbed and tolerated by the stomach. Individuals involved in intense physical activity, especially those limiting their intake of red meat, may have low muscle stores of creatine. Several muscle diseases, as well as rheumatoid arthritis , and chronic circulatory and respiratory diseases , are associated with lowered creatine levels. Two methods are used for supplementing with creatine.