In many Taijiquan styles a breathing method is used.
In our Yang style our breathing method is what I would describe as a paradox method in that we should not breathe in nor breathe out. In this way, our breathing pattern becomes refined and imperceptible.
However, to train and realize this method we must not purposely train it. In fact, all we have to do is to keep working on the form and this method will come out by itself. This is when patience can yield dividends.