Every player who takes the court at that position gets some training proportional to the amount of time they're on the court. So you could conceivably have 12 players get 24 minutes worth of training in a week. (not that you'd want to because the further from 48 minutes a player is, the less effective their minutes are. All your players will get trained, but only those with 48+ minutes will get the full amount of training.
Also, BB rounds up anything from 47:30-47:59 up to 48, meaning your player gets almost all the training. "48+" means the player gets the full training.