## 4 Discussion  
The aim of the present investigation was to evaluate the effects of WBV on MV and physiological parameters during an incremental SB skating test. The results reported changes in ergospirometric parameters and RPE in relation to the rhythm (intensity) of the incremental test in SVB. However, the novelty of this study is its focus on the difference in MV between the conditions in which the incremental test was performed. SampEn was higher when the incremental test was performed with WBV in all the rhythms analysed. In addition, it should be noted that there were no differences between conditions (WBV and non-WBV) in physiological parameters. An increase in training support by exploiting different configurations of information movement within different levels of variability has gained significant traction in recent years. While this study represents the first exploration of MV in a constrained skating environment, several investigations have explored the impact of constraints on MV in human sports performance using entropy analysis [38] (i.e., by analysing video recordings of various sports, including golf and tennis, these studies have revealed changes in variability patterns associated with different constraint conditions). Similarly, more recently, SampEn was validated for MV analysis of running complexity [26]. Moreover, previous studies have indicated an increase in SampEn in the structure of body acceleration patterns when specific ball constraints were introduced for elite rugby players [19; 25; 39]. Our findings align with these previous investigations, which supports the notion that human performance variability is susceptible to environment constraints. Thus, SampEn measures could be a valuable tool for analysing perturbations caused by added constraints. The SampEn values increased in the WBV condition for all players. The results obtained in the present study agree with those reported by [PERSON] et al. [16] who reported that adding mechanical vibration to a half-squat exercise resulted in increased MV. These results suggest that the constraint applied to the SVB exercise induced a change in the coordination patterns of the system or establishes some combination of stability and adaptability of the movement [28; 40]. These findings provide evidence that specific constraints can enhance the adaptive aspects of MV. The relationship between the degree of MV and skill and health is evolving [41]. Some degree of motor variability has been shown to be advantageous as it enables a system more adaptable to internal and external perturbations that constantly affect the body [16; 29]. Therefore, the introduction of a vibration constraint during the SVB exercise impacts the athletes' sliding performance, potentially indicating compromised movement control or coordination in the presence of vibrational constraints. The perturbation observed under WBV could be attributed to the body's transient loss of contact with the SVB surface, leading to a state of being momentarily airborne due to the lack of a firm attachment [12]. Mechanical vibration interferes with postural control through complex integrations involving supraspinal structures, which leads to an increase in phasic muscle activation [42]. As a result, the escalation in MV associated with mechanical vibration could be attributed to the immediate neural modulation triggered by the vibratory stimulus within the central nervous system. It is noteworthy that as the rhythm of the incremental test increased, SampEn decreased when exercise was performed with WBV. This observation was corroborated by linear regression analysis, which revealed an inverse relationships between SampEn vs. HR and VO2 max. Fatigue is known to decrease movement complexity [43]. Some studies have proposed that complexity loss is triggered, or at least influenced, by an increase in metabolic rate [44; 45; 46]. Prior researchers have suggested that peripheral fatigue may cause changes in motor unit discharge, which may be responsible for changes in complexity [46].