## 4 Discussion
### The Effects of EMS on Athletic Performance
It also induces hypertrophic adaptations in Type II muscle fibers, contributing to improved explosive performance and broader applicability in soccer. However, even among studies employing WB-EMS, considerable variations in session frequency, stimulation duration, and integration with voluntary training were noted [26]. This variability contributes to inconsistent outcomes and makes it difficult to identify optimal implementation strategies. A recent study [21] also indicated that WB-EMS could be effectively used as a warm-up strategy, significantly improving short-term sprint performance and offering practical value for pre-match preparation. Nevertheless, [PERSON] et al. (2016) [17] highlighted increased creatine kinase levels following WB-EMS sessions, indicating potential muscle damage and the need for careful management of training load and recovery [27]. Overall, EMS and WB-EMS each present distinct advantages and limitations depending on the context of application. EMS is effective for targeting specific muscle groups, reinforcing precise movement patterns, supporting recovery, and improving isolated motor functions [28]. Its low cost, operational simplicity, and broad applicability contribute to its practicality in both clinical and athletic environments [29]. However, its influence on comprehensive athletic performance may be limited--particularly during in-season periods--as improper integration could interfere with regular training adaptations. WB-EMS offers more systemic benefits for general conditioning, although its application is logistically more demanding, requiring professional supervision, specialized equipment, and careful regulation to avoid adverse outcomes such as delayed-onset muscle soreness or even exertional rhabdomyolysis [30]. When using supraphysiological electrical impulses, muscle soreness--such as delayed-onset muscle soreness (DOMS)--is a common and expected physiological response. It should not be interpreted as an indicator of improper application. DOMS typically occurs following any form of high-intensity training, including EMS, due to microscopic muscle damage and associated inflammatory processes [31]. However, if stimulation parameters such as intensity, frequency, or duration are not properly adjusted to the individual's conditioning level, there is a potential risk of more serious adverse effects, including exertional rhabdomylysis [32]. Determining the threshold between beneficial muscular adaptation and harmful tissue damage remains a key challenge in EMS protocol design. This issue should be addressed through individualized application and careful monitoring. The substantial variability in EMS protocols across the included studies represents a major limitation of the current evidence base. Without standardized parameters, it is difficult to draw definitive conclusions about the effectiveness of EMS or to formulate evidence-based guidelines. Therefore, coaches and practitioners should critically evaluate the strengths and limitations of each modality, tailoring their use based on specific performance goals, athlete characteristics, and available resources. Future studies should aim to standardize EMS protocols and investigate whether combining EMS with other training modalities may produce synergistic effects. Preliminary evidence, such as the combination of EMS and glyometric training shown by [PERSON] et al. (2019) [19], suggests that hybrid approaches may enhance muscle activation and promote superior performance adaptations. Further research is needed to explore these strategies and to optimize EMS applications in athletic performance enhancement.