Pope Pius the XI addressed it, with regard to gymnastics in Convent schools…
In promoting modesty in dress for those under their charge, teaching sisters were complying with Rome’s decrees. In 1930 Pope Pius XI had directed the Sacred Congregation of the Council to issue a strongly-worded Letter on Christian Modesty to the whole world (as had Pope Benedict XV before him):
“Nuns, in compliance with the Letter dated August 23, 1928, by the Sacred Congregation of Religious, must not receive in their colleges, schools, oratories or recreation grounds, or, if once admitted, tolerate girls who are not dressed with Christian modesty; said Nuns, in addition, should do their utmost so that love for holy chastity and Christian modesty may become deeply rooted in the hearts of their pupils.”
The same message was reinforced in all Catholic schools, colleges and universities before the Council. The only concession made for gymnastics and sports in convent schools was shorts of the culotte type with boxed pleats reaching almost to the knee, and then only in an all-girl setting.