Atherosclerosis and inflammatory arterial diseases are rare in young people. Since the early 1980s, an increasing incidence of iliac arterial stenosis in competition cyclists has been reported. Histological findings in these individuals are specific, with fibrosis of the intimal wall on histology and no atherosclerotic or inflammatory lesions. Clinical consequences of this arterial endofibrosis are usually described as an exercise-related subjective sensation of swollen thigh in one or both (15%) legs, with normal clinical and Doppler investigations at rest. Following maximal exercise, ankle-to-brachial systolic pressure index is lower than 0.5 in 85% of individuals with disease and is used as a key argument for diagnosis before deciding upon arteriography. Surgery (recalibrated saphenous grafts or angioplasty-endofibrosectomy) seems to be efficient to allow an early return to competition, but its long term results are still to be evaluated. The physiopathology of this disease and its possible relationship with atherosclerosis are unknown.