The new sport organizations were part of a much larger phenomenon: in the second half of the nineteenth century, voluntary associations moved like wildfire around the planet, jumping from continent to continent within only a few years even when travel could take weeks or even months. Physical education emerged as a professional field in the 1880s, and its practitioners used classicism to legitimize their craft, claiming that mens sana in corpore sano was an ancient Greek ideal. German gymnastics were preferred in military schools worldwide, modeled after the admired Prussian military. British sports were preferred in schools modeled after the British public schools that prepared young men for capitalism and colonial service. The commercialization of soccer and the huge global audience ultimately made Fédération Internationale de Football the only sport organization with enough wealth and power to rival the International Olympic Committee (IOC). In 1988 the IOC finally opened up the Olympics to professional athletes.