This book strikes a balance between international sporting governing bodies' interests and values enshrined in rules regarding sporting nationality on one hand, and athletes' rights under EU law on the other. It argues that some rules governing athletes' eligibility in national teams in their current form, notably certain waiting periods, quotas for naturalised athletes or athletes having previously played for another country, and rules prohibiting the change of sporting nationality, constitute a disproportionate restriction on athletes' rights under EU citizenship, free movement of persons, competition law or fundamental rights. Accordingly, the book subsequently presents concrete recommendations for international sporting governing bodies on how to reconcile their interests and values with the rights that athletes enjoy under EU law. As such, it offers an essential guide for these bodies and their representatives, as well as for athletes, academics and practitioners in the fields of law and sports.