## 4 Discussion
The reduction in non-perseverative errors on the WCST may reflect improved attention, inhibition, and overall working memory [54]. Meanwhile, a previous study [55] suggested that transient hypofrontality occurs during high-intensity exercise, but not during low- and moderate-intensity exercises. Nevertheless, a certain level of intensity seems to be needed in order to release dopamine and influence the activation of different cortex areas [56; 57]. The Contingent Continuous Performance Task and WCST tests were used in a previous study [58] as measures of executive control. Following the ventilatory threshold, executive control performance remained poor, possibly owing to the additional amount of time which the brain needs in order to return to homeostasis following intense exercise. According to [PERSON] et al. [59], tentative explanations for the exercise effect postulate that exercise allocates attention resources, influences the dorsolateral prefrontal cortex, and is implicated in exercise-induced dopamine release. Widely in use for more than half a century after the initial presentation of the WCST, there are limitations to classical tasks with VR which must be overcome [60]. Nonetheless, WCST in VR has been comprehensively used in neuropsychology clinical research [61] and in physically unhealthy older adults [24]. There are no previous studies with exercise to the knowledge of the researchers of this study. Therefore, the results are compared with other topics similar to current research. Once [PERSON] et al. [62] developed a two-choice rule-switch task with mice, they concluded that the animals learnt to discriminate between the visual cues and successfully switched their strategies according to the related rules. The findings support the role of prefrontal networks in mice for cognitive flexibility. In a previous study, [PERSON] et al. [63] used VR technology to induce stress and to test three main cognitive functions for decision-making in stressful situations. The results indicated that if someone perceived the virtual Trier Social Stress Test (TSST) as unexpected, as an indicator of a mild stress response, their cognitive flexibility was improved; meanwhile, the authors of [64] examined the VR more closely to approximately reflect real-life settings, distractions, and common interchanges using WCST and Look for a Match (LFAM). The results demonstrated that the participants found LFAM to be more enjoyable and interesting, whereas they found the WCST to be easier. Maintaining a certain level of physical activity has beneficial effects on the body itself but also, surprisingly, on cognition [65]. Despite new developments, a large portion of VR's potential is still unexplored; therefore, real experiences in a flexible context that combine relevant cultural, physical, and cognitive aspects are necessary [66]. To date, cognitive flexibility has been measured only using neuropsychological tasks; therefore, the VR task was developed to evaluate cognitive flexibility [67]. A previous study [68] investigated immersive VR as a novel technique to test the executive function of healthy younger and older adults. The conclusion drawn from the study indicated that immersive VR measures were found to be stronger contributors than existing traditional neuropsychological tasks in predicting age-related cognitive decline. Accordingly, the physiological explanation of VR in improvements of cognitive reality is severely limited. To the best of our knowledge, this is the first study conducted with healthy adults in this field; hence, there is no point of reference with the same population as to the current study. Nonetheless, the authors of [69] studied older adults at risk for mild cognitive impairments, the authors of [70] studied patients with brain injury, and the authors of [71] studied cardiac rehabilitation patients--all utilized the Stroop test. Performance in VR was present in all three studies.