The bicuspid aortic valve (BAV) is the most common congenital heart defect among adults, often leading to severe valve dysfunction and aortic complications. Despite its clinical significance, uncertainties persist regarding the impact of sports participation on the natural course of BAV disease. The SPREAD (Sport PRactice and its Effects on Bicuspid Aortic valve Disease) study is a multicenter and multinational project designed to investigate this relationship. This paper outlines the study's design, and objectives. The study is divided into two phases; phase one involves a cross-sectional analysis comparing aortic dimensions and valve function among competitive athletes with BAV, athletes with tricuspid aortic valves (TAV), and sedentary individuals with BAV. The second phase is a prospective, longitudinal follow-up aiming to evaluate the impact of regular sports training on disease progression. The SPREAD study seeks to provide evidence-based insights into the effects of sports participation on BAV disease progression, guiding clinical decision-making regarding sports eligibility and risk stratification for individuals with BAV.