Hormones and athletic performance.

Physical activity exerts an important influence on the endocrine system, modulating synthesis and secretion of several hormones. Almost every organ and system in the body is affected by physical activity and exercise, mainly through the endocrine and neuroendocrine system. Mode, intensity, and duration of the exercise bout, age, gender and fitness level of the individual as well as environmental and psychological factors may affect the endocrine response to physical activity. Several hormones are able to influence physical performance and body composition. Thus, a bi-directional interrelationship between exercise and hormones exists. In the past decades, hormone abuse has become a widespread habit among professional and recreational athletes. A substantial part of this chapter is devoted to the effects of exogenous hormones on physical performance. Anabolic steroids, growth hormone and GH secretagogues, insulin-like growth factor-I, insulin, erythropoietin, and glucocorticosteroid properties, use and misuse in sports are widely described. Specific methods to detect hormone abuse are presented and discussed. The purpose of this chapter is to provide all professionals involved in sports medicine and endocrinology a state-of-the-art overview of the complex interactions between physical activity and the endocrine system and to focus on hormone abuse in sports at competitive and recreational level, highlighting its negative consequences for long-term health.