“The aim in Yoga is to train ourselves so that we can modify
inhalation or exhalation and hold the breath to meet a demand.
That is why we develop different ratios.
If these things can be done,
and if we need a particular ratio,
it is in our pocket.”
– TKV Desikachar ‘Choosing a Ratio and the proper technique for Prāṇāyāma’
Religiousness in Yoga Chapter Twelve Page 173