NCAA practice/training question

What are the rules regarding how much an NCAA athlete can be spent pursuing his/her sport? I understand that players have limited numbers of practices, hours a week, etc, but I was wondering about time spent in workouts, training room, film study, etc. Is that monitored (or is that even possible)?

Take our early enrollees. If Hayden Rettig wants to spend 6 hours a day breaking down film and getting informal throwing technique training from a "staff advisor", can he do that? Does that constitute a practice? I've often wondered how much coaches demand from their players at big time programs, given the severe limitations on the number of formal practices.