Sports competitions were originally organized for several reasons, but one of the most significant was to foster competition and resolve disputes between tribes, cities, or nations without resorting to warfare. For example, the ancient Olympic Games in Greece were held not only as a festival of athletic prowess but also as a means of promoting peace and unity during times of conflict, as the Games would often come with a truce that allowed participating athletes and spectators safe passage.
While demonstrating physical strength and athletic ability may have implications for military readiness, this was not the sole purpose of organizing competitions. Additionally, while there have been instances of gender divisions in sports, the initial organization of sports was not explicitly about proving which gender was stronger, but more about showcasing human capability in various physical disciplines.
Thus, the primary reasons sports competitions were first organized included resolving disputes and promoting peace among competing groups, rather than solely appealing to concepts of military readiness or gender comparison.