Canon LXXI.
The Quinisext Council in Trullo (692) · The Seven Holy Ecumenical Councils
Those who are taught the civil laws must not adopt the customs of the Gentiles, nor be induced to go to the theatre, nor to keep what are called Cylestras, nor to wear clothing contrary to the general custom; and this holds good when they begin their training, when they reach its end, and, in short, all the time of its duration. If any one from this time shall dare to do contrary to this canon he is to be cut off.
Trull 1.72.2
Whoever devotes himself to the study of law, uses the manner of the Gentiles, going to the theatre, and rolling in the dust, or dressing differently to custom, shall be cut off.
Trull 1.72.5
Liddell and Scott identify καλίστρα with καλινδήθρα , which they define as “a place for horses to roll after exercise,” and note that it is a synonym of ἀλινδήθρα. But it is interesting to note that ἀλίνησις is “a rolling in the dust, an exercise in which wrestlers rolled on the ground.”
Trull 1.72.6