Endocrinological Aspects in Handball

The effectiveness of physical training depends on the training load and on the individual ability to tolerate it, and an imbalance between the two may lead to under- or overtraining. Therefore, many efforts have been made to find objective parameters to quantify the balance between training load and the athlete’s tolerance. One of the unique features of exercise is that it leads to a simultaneous increase of antagonistic mediators. On the one hand, exercise stimulates anabolic components of the growth hormone (GH) ? IGF-I (insulin-like growth factor-I) axis. On the other hand, exercise elevates catabolic pro-inflammatory cytokines such as interleukin-6 (IL-6). The very fine balance between the anabolic and inflammatory/catabolic response to exercise will determine the effectiveness of exercise training and the health consequences of exercise. In this chapter, we review the changes in the anabolic-catabolic hormonal balance and in circulating inflammatory cytokines both in single exercise bouts and following training, and we demonstrate how these changes may be used by athletes and/or their coaches to gauge the training intensity focusing on team sports and in particularly handball.