“Mental attitude is very important in the practice of Prāṇāyāma.
In Prāṇāyāma we have no body movement to see; it involves mostly what we feel.
The only thing dynamic in Prāṇāyāma is the breath.
Yet, we must have the same attitude of attention in Prāṇāyāma, as in Āsana.”
– TKV Desikachar Religiousness in Yoga Chapter Nine Page 125