Competitive sport on high levels is far from being healthy. Strenuous physical activity on the way to the medal is far from being physiologic. In fact, we have now ways and means to evaluate the immediate muscle damage and the accumulation of metabolic products causing pain and other physical phenomena by which the body notifies us about this suffering. It is important to find ways and means to decrease body discomfort or to reduce the tissue damage, and to avoid exercise stress-related health risks. On the other hand, from the medical point of view we have to provide athletes with adequate nutrients and energy for the maintenance of homeostasis. Doing this, the question is, what is the border between doping and preventive medicine? Energetic and nutritional needs of athletes are higher than those of sedentary people. Where is the border between adequate nutritional supplementation aimed at maintenance of appropriate body composition, energy stores, and body mass on one hand and nutritional overload for the improvement of athletic performance in elite athletes on the other hand? Very often, there are possible links between “supplements or ergogenic compounds” and the endocrine-metabolic system.