The final paper of "The Importance of The Plyometric Training in The Fitness Preparation of Athletes" methodologically contains four significant parts: plyometric training, fitness preparation of an athlete, the importance of plyometrics in the fitness preparation of athletes and research. The first part of the paper focuses on the history and definition of plyometric exercises, the second part refers to the fitness preparation of athletes , the type and principles of fitness training, and the third part with the importance of plyometric training in fitness preparation of sports and the papers in which the authors describe plyometric training and its uses. The fourth part of the paper describes and presents the research. The research was intended to examine whether the trainers of fitness training of athletes use plyometric training in their work and its importance on the values and benefits in fitness training of athletes. The key problem that the research deals with is whether the training of pliometrics leads to the appearance of overtraining and whether it is stressful for the organism. The obtained results show that despite these possible side effects, fitness training believe that plyometrics training is important in fitness training of athletes, as many as 84% completely agree with this statement.