If you want to claim that there are not sports specifically appropriate for one gender or the other, you can talk about the claims for the opposite argument (that there are sports more appropriate for men or women), and then disprove those claims. For example, if someone argues that baseball is not appropriate for women to play, you can talk about Eri Yoshida, a female baseball player who was drafted to play in the Japanese professional league at only 16 years old. You can also point to the movie "A League of Their Own," in which women play professional baseball to replace the men's team during wartime.
