Is physical training in mosques permissible?

Question:
Your Eminence, Shaykh Abdul Aziz, peace be upon you and Allah’s mercy and blessings. After that: I am one of the trainers in a military college for the sport of karate, which is a self-defense sport. The college does not have a designated place for training, so is it permissible for me to conduct the training in a place that is being built on the basis that it will be a mosque, but is not yet completed?

Answer:
As long as this training is beneficial in the path of Allah and in jihad against His enemies, there is no harm. The Messenger of Allah (peace and blessings be upon him) approved the Ethiopians, and they played in the mosque with spears and lances, moving around in the mosque with spears and lances.
So if the sport is used to aid in defending oneself, jihad against enemies, and protecting against their harm, there is no harm in a mosque that has an open area and sufficient space, until another place is found where the play can take place, on the condition that this play does not cause harm to the mosque through destruction, urination, or the like.