## 1 Introduction
Furthermore, this knowledge of body composition has been suggested to discriminate athletes of different performance levels [17]. If the four electrodes are located on a specific muscle, it can be named both as muscle-localized BIVA (ML-BIVA) and electrical impedance myography (EIM). There is less consensus about the exact location of the electrodes regarding ML-BIVA, since the scientific literature is scarce and heterogeneous. ML-BIVA has mainly been studied in medicine in a wide range of different clinical conditions [18; 19]. However, in recent years there has been growing interest in its applicability in the high-performance sports field [19], and in the assessment and follow-up of muscle injuries [20; 21; 22; 23; 24]. The most analyzed muscles are the quadriceps, hamstrings, and calves, as they are long muscles that allow an easier assessment than others. The information provided by this method could help technical and medical staff to make decisions about their athletes. Unlike BIA, BIVA does not provide a quantitative evaluation of the outcomes; thus, making a single measurement may be inefficient, since one of the main strengths of BIVAis to analyze how the vector changes over a given period of time and under previously established circumstances, e.g., comparing impedance values before and after intense physical exercise. Another interesting aspect of BIVA is its ability to make a comparison of bioelectrical data, without the need to perform a PRE-to-POST comparison, based on specific sectors of the population that may be different (e.g., healthy adult reference population) or similar than the subject under analysis. Furthermore, BIVA may be of great use in the assessment of body composition, considering that this issue is important since the physical stress imposed during exercise may lead to body composition alterations causing a poorer performance [25]. In addition, dehydration can also impair performance [26; 27] and increase the risk of injury [28], thus monitoring body fluid can assist in prescribing water intake and mitigating dehydration effects. Lastly, one of the main interests regarding BIVA and sport lies in the analysis of how the impedance parameters correlate to other indicators that also serve as exercise response markers. Some of the pioneers of this possible application were [PERSON] et al. [29], who reported that whole-body vector displacement could be correlated with some biomarkers of renal damage at 24-48 h post-race but not with CK. Thus, this study aimed to analyze the kinetics of BIVA parameters (global and muscle-localized), which can provide information about the degree of dehydration, the physiological training effects, and the cellular integrity of muscle induced by a session of high-intensity training in risk hockey players. Furthermore, we also aimed to analyze if some of these BIVA parameters are correlated to CK changes, since both are markers of adaptation to exercise that may indicate that muscle damage has occurred after training. In this sense, it is now recognized that the evaluation of body water is a dynamic and complex process, and that no measure is valid for all situations [30; 31]. It is for this reason that BIVA emerges as a precise, accurate, reliable, non-invasive, portable, cheap, and safe method that can easily be used to assess hydration status in real time [32]. These properties are particularly interesting for the evaluation of sport for both the training process as well as in competitive events. The present study analyses anthropometric adaptations, bioelectrical data (global and localized), and their relation to the behavior of CK, beforehand, afterwards, and 24 h after a high-intensity risk hockey training session.