Some sports would have both participation from women and men while some sports are only played by men, like american football. This is the reason why I choose the photo above since it reflects the most on this issue.
I just wondering if women have the ability to withstand the tackles like those players in the picture above deal with. However, it mights be interesting to watch women play football and have their own national league.
They tried having a female football league, and actually it still might exist. It wasn't very successful though.