## 4 Discussion
Research has reported varying findings regarding the relationship between the training load and HRV in elite athletes. Some studies suggest that HRV progressively decreases with an increasing training load [21, 26], while others reported statistically significant effects without a consistent pattern [46]  
Despite these discrepancies, researchers generally agree that a stable or increasing HRV trend in response to higher training loads indicates a positive adaptation to training. At the same time, a decline in HRV may signal excessive training stress, which could lead to overtraining [47, 48]. Our study found no significant variations in HRV trends related to the training load. This lack of differences may be attributed to individual differences in autonomic regulation, variations in methodology, or effectively managed training loads that limit excessive physiological stress. Additional research is essential to clarify the relationships between these findings further. In previous studies, HRV has rarely been investigated in the context of competitive sport performance. Several studies reported a positive correlation between HRV and ability testing. [PERSON] et al. [49] reported that lower daily HRV values are associated with poorer abilities on bikes. [PERSON] and [PERSON] [50] found that underperforming athletes have higher parasympathetic tone and lower HRV compared to performing athletes in a competitive context. The association mentioned above may initially seem surprising, as higher HRV is generally associated with better health and greater performance, but researchers have found that HRV usually decreases before competitions, as an increase in sympathetic activation is linked to pre-competition stress. An increase in sympathetic activation correlates with a higher cardiac output, elevated catecholamine release, and improved oxygen delivery to active muscles, all of which contribute to enhanced acute exercise performance [22, 23, 51]. Some research reports a decrease in HRV only before competitions, which athletes consider to be more important [23, 52]. Our study indicates a similar pattern to previous studies, with HRV values showing a decrease during competition weeks compared to non-competition periods. This difference did not reach statistical significance, but this trend is consistent with previous findings. HRV during the competition week was lower than in the preceding period, with an additional decrease on competition day. [PERSON] et al. [53] reported a reduced HRV during the week of competition, but there was no evidence of an effect on competitive performance in elite rowers. [PERSON] et al. [54] found that lower HRV appeared to be a good indicator of sports performance in elite long jumpers participating in the Rio de Janeiro Olympic Games. While few studies have explored the effect of HRV on athletic performance, they indicate the possible value of HRV as a marker of athletic performance. Depending on the specific demands of each sport, future research should explore the value of an autonomic profile that enhances competitive performance. While our study did not establish a clear relationship between HRV and sports performance, the decline in HRV we observed before competitions indicates a possible advantage of increased sympathetic activation.