## 4 Discussion  
Both of the stated research hypotheses were confirmed. It was shown that the body composition of the athletes was significantly related to the results obtained by the wrestlers studied in the performance test. It was noted that wrestlers with higher FM [%] obtained significantly lower results in the performance test, while wrestlers with higher FFM [%], TBW [%], and MM [%] obtained higher VO2 max on the first test date. Athletes in the period of adolescence must be provided with an adequate diet to cover their energy needs resulting from daily functioning, the development of the body, the building and development of the osteoarticular system, the building and rebuilding of muscle tissue, as well as the implementation of the training process [36]. The results of the study also confirm the need to provide athletes with supplies during the immediate preparation period for major competitions in terms of energy security and hydration of the body. Similar correlations were indicated by [PERSON] and co-authors (2018), demonstrating that a diet providing energy requirements is one of the important determinants of wrestlers' effective implementation of an aerobic training program [37]. It should be noted, however, that the body composition of the subjects, analyzed in [%], did not show a significant relationship in the second term of the study, and the level of VO2 max significantly increased between the first and second terms of the study. The subjects in the second term obtained the highest levels among the results of aerobic capacity available in the literature for wrestlers in the cadet age group [38]. This may indicate the presence of another factor influencing the results obtained by the subjects in the second trial. Previous studies have shown that training experience is only one of the factors affecting the results obtained in wrestling competitions [39]. In addition, in the junior group, relative age effects [40], which, along with training experience and higher levels of aerobic endurance, are important factors that distinguish elite wrestlers from amateurs aged 15-17 [41]. This indicates that athletes who have started sports training earlier have a greater chance of achieving competitive success in younger age groups in wrestling. It should be noted, however, that even when starting wrestling training at a very young age, too early specialization should be avoided, as research shows that it is injury-prone during the long-term training period [42]. The above indicates that for wrestlers competing in international championship competitions who are in the period of puberty, it is necessary to constantly control this process as well as provide them with a diet adapted to the changes resulting from the maturation process and training loads. At the same time, due to the changes occurring during this period, premature sports specialization should be avoided, and for athletes with more training experience, all-around fitness training should not be excluded, as it is one of the determinants of success in wrestling during adolescence [43]. It has been reported that higher FM [%] and FM [kg] levels have a significant decrease in the level of Klonowicz COR 3 min after exercise and increase the level of resting heart rate between the second and first terms of the study. At the same time, it was shown that a higher level of FFM [%], TBW [%], and MM [%] significantly improved the Klonowicz COR 3 min after the workout, and decreased the level of resting heart rate between the second and first testing terms. Wrestlers characterized by lower levels of body fat have a better-developed autonomic heart rate regulation system [21]. Previous studies have shown that wrestlers with a higher FM level [%] have a significantly poorer post-exercise recovery rate in the wrestling special fitness test [44]. Wrestlers often aim to achieve a lower level of body weight before competition through rapid weight loss (RWL).