Answered by Shaykh Amjad Rasheed
Is it permissible to use the masjid hall for Kung Fu and other forms of physical exercise, particularly if it’s difficult for Muslims to gather in other places?
What can be inferred from the words of our imams is that doing this in the masjid is not forbidden, because it is rigorously authenticated in the Saheeh [m: of Imam Bukhari] that the Abyssinians danced with their spears in the masjid and the Prophet (Allah bless him and grant him peace) consented to them doing this. However, [m: the imams] clearly state conditions: that doing so should not damage the furnishings of the masjid, such as its carpet and the like and that it should not disturb those praying, sleeping, or reciting the Qur’an; otherwise, it is forbidden.
If we say that this is permissible, it would become disliked if it involves the raising of voices, for this is disliked in the masjid except when teaching or making mention (Ar. dhikr) of Allah Most High. It is better to avoid using the masjid for such activities because of the hadith of our master Anas Ibn Malik (Allah be pleased with him) who narrates that the Messenger of Allah (Allah bless him and grant him peace) said, “These masajid are not appropriate for urination or filth. They are merely for remembrance of Allah and recitation of the Qur’an.”
Amjad Rasheed
(Translated by Sidi Moustafa Elqabbany )