The SUPPORTER project aims to foster gender-related, sustainable, and transformative institutional changes in sports higher education institutions paying specific attention to the challenge of gender-based violence and leading to the development of inclusive, innovative, intersectional and impactful gender equality plans (4I-GEPs). These include a set of grounding actions towards to achieve institutional changes. This poster, presented at SUPPORTER's final conference, presents a grounding action undertaken by the Faculty of Physical Education and Sport at Charles University which aims to explore how constitutive and eligibility rules in sport create structural inequalities, particularly disadvantaging female athletes, and to pilot unisex sports models that promote fairness for all gender.