Our contribution, backed by research conducted because of dissatisfaction from the field of volleyball training proposes an emerging design that makes sensitivity as a crucial vector of expertise. As part of the recent extensions of the enactive approach and philosophy of life, norms and values from Canguilhem, our study of the activity of two volleyball expert players suggests that sensitivity to is the entity integrating affectivity cognition and motricity as well as the human mobilization instance to what matters to him. We show that experts and some novices have a common sensitivity to and we list the reasons why it promotes access to expertise. Expert and novice should not be seen as opposites, and it is necessary to distinguish and connect two lines of analysis: sensitivity and expertise. We defend the principle that understanding the expertise requires understanding the conditions that favor it in order to design training aimed its access.