## 4 Discussion  
The main objective of this study was to investigate whether wrestlers of different competitive qualities would differ in the performance, cardiac, and metabolic parameters in SWFT after repeating tests which created physically demanding testing protocols. According to the objectives, the main findings of this research are as follows: (i) Wrestlers of different competitive qualities did not differ in cardiac or metabolic variables in either of the SWFT trials; (ii) Wrestlers of different competitive qualities differed in terms of performance variables; successful wrestlers achieved a greater number of SWFT throws and had more favourable SWFT indexes in the second testing trial than did less successful wrestlers. Therefore, our study hypothesis can be partially accepted. Differences in Cardiac and Metabolic Variables during Repeated Trials of Specific Wrestling Fitness Tests  
The finding that cardiac and metabolic variables did not differ between wrestlers of different competitive qualities in either testing trial can be explained as follows. The noted results are supported by the results of previously published studies using a similar methodology. Specifically, a study on adult wrestlers from Serbia reported that the cardiac and metabolic responses of national, first, and second-league wrestlers did not differ according to the SWFT [13]. Moreover, a study on Croatian wrestlers revealed no significant differences in the La concentrations accumulated during a wrestling match between the national team and club-level wrestlers [7]. This could be explained by the fact that the SWFT and the biggest part of the wrestling match are predominantly anaerobic-glycolytic activities, which lead to high production and accumulation of blood La, placing high demands on aerobic metabolism (cardiovascular functions) to remove La from the blood during recovery [7; 13]. Therefore, wrestling-specific performance corresponds to match requirements and leads to adaptations in cardiac and metabolic outputs [22]. To simplify, more successful wrestlers had advanced cardiac and metabolic adaptations, which allowed them to achieve better results and to resist fatigue during the testing trials, even though their absolute measures of physiological response were similar to those of less successful wrestlers. A similar explanation was provided by [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] [13], who noted that wrestlers at higher levels could deliver larger amounts of oxygen to muscles included in the test for the same HR and execute a greater number of throws for the same La concentrations, which was explained by the increased oxygen capacity and higher contraction intensity of the muscle resulting from peripheral adaptation [13; 28]. A study on Croatian wrestlers aged 15-20 years that examined the dynamics of blood lactate production hypothesized that training-induced metabolic adaptations enable high-quality wrestlers to operate for longer periods and under greater loads, and they also create more blood lactate at greater intensities and remove it faster [29]. This might also be affected by increased buffering capacity, which enables well-trained athletes to generate ATP via glycolysis [30]. According to the results of our study and those of similar previous studies, the absolute values of cardiac and metabolic variables (i.e., HR and La) are not accurate representations of physiological response because they do not consider the efficacy of the work that the wrestler is performing [31]. Therefore, cardiac and metabolic responses to effort should be adjusted to real performance because wrestlers with greater performance and the same cardiac and metabolic responses have better specific training adaptations and overall physical performance. Thus, the creators of the SWFT have proposed using index values that take into account cardiac and metabolic responses calculated together with performance values (i.e., number of throws) [10].