3. In Article 29 of the [1976 NI 15] Sex Discrimination (Northern Ireland) Order 1976 (which excepts physical training courses from the application of provisions of that Order making sex discrimination in education unlawful), sub-paragraph (b) (courses for teachers of physical training) and the word “or” preceding it shall cease to have effect except in relation to persons admitted to courses in an academic year beginning in a year earlier than the year in which there falls the day on which this Order comes into operation.