We already have those leagues now... they're just called rec leagues. One issue I could think of is women playing a sport which has considerable groinal contac

We already have those leagues now... they're just called rec leagues. One issue I could think of is women playing a sport which has considerable groinal contact, such as basketball. I'm sure there is some amount of women players who would not be comfortable with men essentially grinding up on them in the paint. For those without experience, if you are offensively in the paint a typical strategy is to shove your butt out into the defenders groin to create space. By making all sports coed you invite the potential for more sexual harassment, especially at the lower levels of competition due to the close skill levels between minimally athletic men and moderately athletic women.