This graduate thesis deals with the issue of starting to play sports in childhood and the impact of training on the health of child athletes. The entire work starts from the idea that starting to play sports at an early age destroys the health of athletes. Before the actual research, all aspects of the entire topic were studied through the professional literature. Thus, in the first part of the paper, it is generally about the beginnings of playing sports, the concept of sports training, the relationship between children and sports, the role of the media in the popularization of sports, abuse of children in sports, and developmental stages. The paper uses the case of Ana Konjuh, which by its characteristics corresponds to the chosen topic. Namely, Ana is a Croatian tennis player who started tennis training at an early age. The goal was, in her case, to investigate the cause of her injuries, whether the occurrence of injuries can be connected with early involvement in sports. In the second part of the paper, a survey was conducted in which eight respondents participated. All respondents were chosen based on the criterion of a close connection with sports. The semi-structured interview method was used. The results of the research lead to the conclusion that starting to play sports at an early age damages children's health and that children's health is neglected for the sake of sports success. The purpose of the entire work and the reason for the research is that modern professional sports increasingly require an earlier and earlier start of intensive training, and these trainings are more and more intense. The consequences of this are more and more frequent, sometimes serious, permanent injuries, even among the youngest. Unfortunately, the negative side that is mentioned less often, where sometimes the victims are children.