The spectrum of hormones in sports doping
Physical activity exerts an important influence on the endocrine system, modulating synthesis and secretion of several hormones. On the other hand, several hormones are able to influence physical performance and body composition. Thus, a two-way relationship between exercise and hormones exists.
The use of performance-enhancing compounds dates back to the initial Olympiad in ancient Greece where herbal remedies and animal extracts were used by the athletes before competition. In the past decades, hormone abuse has become a widespread habit among professional and - most of all and more frequently recreational athletes. Anabolic androgenic steroids (AAS), GH and erythropoietin (EPO) are the most frequently abused hormonal substances in sports. The use of AAS as performance enhancing drugs dates back at the 1936 Olympic Games in Berlin, shortly after testosterone was first isolated and synthesized. GH was introduced to the world of sport by the Underground Steroid Handbook, a leaflet published in 1982 and used in the 1988 Olympic Games. Recombinant human EPO has been imputed to be abused by athletes in aerobic sports early after its marketing as an erythropoiesis-stimulating drug.
AAS are chemically modified analogs of testosterone which act on the skeletal muscle as a primary target tissue. The anabolic effect of testosterone is dose dependent, and significant increases in muscle size and strength occur only with supra-physiological doses. GH is used as a drug of abuse in sports, although there are no proper scientific studies demonstrating GH to be performance enhancing in normal subjects. EPO stimulates an increase in hemoglobin thus increasing the oxygen-carrying capacity of the blood.
The adverse effects of hormone abuse are numerous and affect several organs and body systems leading to increased mortality. Thus, hormone abuse among athletes and specific subsets of the general population represents a major public health issue which requires further research in sports endocrinology and widespread educational programs.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.