All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is not permissible to participate in matches between men and women as this is a means which provokes corruption and because forbidden mixing in it is inevitable. Therefore, one should not doubt about the prohibition of such a matter and this cannot be compared to the mixing at the work place because it is possible to abide by the Islamic requirements at the work place whereas it is it is not possible to abide by them in mixing when practicing sports. For more benefit, please refer to Fataawa 91237 and 83953.
Allaah Knows best.