Scholar: Imâm ´Abdul-´Azîz bin ´Abdillâh bin Bâz
Source: http://binbaz.org.sa/mat/11065
Reference: Darulhadith.com
http://aFatwa.com

Question: What is the ruling regarding women’s sports?

Shaykh Ibn Bâz: It varies. It is permissible if it occurs only among women in a way that does not contradict the Sharî’ah. An example of it is running in a place that is separate for women and [a place] that men can’t visit. Another example is swimming in their houses or in swimming pools where no men can visit. If the men neither can see them or come in contact with them, the deed [would then be] allowed.

But if the deed is practiced by both men and women together or that the men see the women or that there are factors that harm the Muslims, the deed would then not be considered as allowed. Thus, this matter is detailed.

It is namely allowed if the deed is specific for women and no sins occur while it does not occur mixedly with men such that the place is hidden and distant from the men. This is concerning running, swimming and other competitions.