Products
Creatine (synonym: creatine) is commercially available as a dietary supplement in powder, tablet, and capsule forms, among others. It has gained popularity since the early 1990s and is now taken by many athletes. Creatine should not be confused with keratin, creatinine or carnitine. Creatinine is a breakdown product of creatine that is excreted in the urine.
Structure and properties
Creatine (C4H9N3O2, Mr = 131.13 g/mol) is a natural and nonessential guanidino compound formed in the body in the liver and kidney from the amino acids glycine, arginine, and methionine. Creatine is also absorbed with food when consuming meat, fish and milk. In muscle, it is present in a large proportion (2/3) as creatine phosphate, which is formed by phosphorylation from creatine with ATP. This reaction is catalyzed by creatine kinases.
Effects
Creatine is found in the human body primarily in skeletal muscle (about 95%), but also in the central nervous system and heart. In the muscles, it increases the available energy and leads to an increase in performance during short and intense physical exertion. The effect is based on the rapid rephosphorylation of adenosine diphosphate (ADP) to adenosine triphosphate (ATP). In this process, a phosphate group is transferred from creatine phosphate to ADP. Creatine promotes the building of muscles. It increases muscle mass and strength, provided that regular exercise is performed. It has been proven that the amount of creatine phosphate in muscle is increased by supplementation. Creatine is well documented scientifically and is considered effective.
Areas of application
As a dietary supplement for sports, bodybuilding and rehabilitation.
Dosage
According to the product information. For adults, the regular intake of 3 g per day is recommended. At the beginning, a higher saturation dose can also be administered. For the exact information, please refer to the literature (e.g., Kreider er al., 2017).
Abuse
Creatine is not on the doping list and may be used during and outside of athletic competition.
Contraindications
- Hypersensitivity
- (kidney disease)
- (Children and adolescents)
The full precautions can be found in the literature.
Adverse effects
Creatine is considered well tolerated and there are few known side effects. This is with the exception of weight gain, which is related to water retention.