Dr Arroyo graduated from the University Autonoma of Guadalajara and completed a fellowship in sports medicine in Columbus, Ohio. He focuses on the pathologies of soccer players, related to physiology and traumatic injuries. He lectures and publishes research on soccer internationally. He has worked in sports medicine since 1989 with professional and amateur athletes from a variety of sports, including five professional soccer teams, American football, professional basketball, Olympic volleyball and tae kwon do teams, and is also medical advisor to the marathon organisation in Guadalajara.