How should we breathe when we do our tai chi form, of whichever lineage? The correct, but not so correct, answer is 'normal breathing'. Why not so correct? It is because we have to learn power breathing first before we can do proper tai chi form using normal breathing. And tai chi form has to be done using normal breathing that can have the effect of power breathing. If the above doesn't sound too strange to you, read on!
Before we can put down something we have to lift it up in the first place! It is essentially the same in the practice of tai chi. Tai chi is moving meditation. A student has to do it slowly with a meditation mind in a meditative zone. And only in a meditative zone can a student relaxes his joints and allow his breathing muscles to do their proper job, in addition to allowing inertia and the force of gravity to take part. Such meditative approach however will be ineffective without prior conditioning of one's body - or "lifting it up first".
How to train our body (or lift up our body)? There are two basic areas to be trained: the first one is opening one's shoulder and hip joints, our major joints, primarily using the method of "finding points maximum resistance", and the closely related second one is learning how to do power breathing.
I have explained the former in previous posts. Breathing needs more explanations here.
Firstly, tai chi breathing, when doing tai chi forms, requires a practitioner to be able to generate chi both while inhaling or exhaling. When a student can do it this way, he can forget about when to breathe in, when to breathe out; his simply needs to breathe as his movement flows.
Secondly, while breathing (inhaling and exhaling), our breathing muscles (primarily our diaphragm) must be able to open our joints (hence joint opening has to be/is being trained together with power breathing). Power breathing is like weight lifting. The weight to overcome here is the "sluggishness of our joints".
Thirdly, such power breathing has to be trained separately (with some prior joints opening training) and preferable with the personal guidance of a good teacher.
Traditionally, such training is to be done separately from tai chi form. And it is traditionally call tai chi nei-gong or tai chi chi-kung.
The training sequence should be: first tai chi chi-kung (both power breathing and joint opening), second tai chi form and finally tai chi chi-kung and tai chi form in sequence during a training session.