A drug that has a structure and function similar to that of the hormone testosterone. AASs are prescribed for medical use, but they are on the World Anti-Doping Agency's 2005 Prohibited List. There are two main types of AAS:
1 exogenous AAS (substances that are not capable of being produced by the body naturally, e.g. danazol, metenolone, and nandrolone).
2 Endogenous AAS (substances that are capable of being produced by the body naturally, e.g. dehydroepiandrosterone or DHEA, 19-noranrdosterone, and 19-noretiocholanolone). Both exogenous and endogenous steroids, as well as their analogues (any substance formed by modifying the chemical structure of another substance while retaining a similar pharmacological effect) are prohibited inside and outside of competition. An athlete is deemed to contain an endogenous AAS on the Prohibited List if the concentration of the substance (or one of its metabolites) in the urine sample is greater than the amount normally found in humans. The athlete is not deemed to contain the prohibited substance when the athlete can prove, by evidence, that the excess concentration of the exogenous substance is due to a pathological or physiological condition. Anabolic Androgenic Steroids are usually taken in tablet form or by intramuscular injection to improve muscle strength, power, and size. They encourage retention of nitrogen, potassium, and phosphate, increase protein synthesis, and decrease amino acid breakdown, but their effects are dose dependent. They may also increase tolerance to hard training by improving tissue repair and by delaying fatigue. Doped athletes may also feel stronger, more aggressive, and more confident. Among teenagers and children, the use of anabolic steroids can adversely affect skeletal growth, leading to premature fusion of the epiphyses. In adults, AAS may produce psychological changes (e.g. the so-called ‘roid rage’), and damage the liver and heart. In males, excessive levels of testosterone may reduce the size of the testes and affect sperm production. In females, testosterone may cause masculinization. AASs are responsible for much drug abuse in sport.
Subjects: Sports and Exercise Medicine.