Old hatha yoga books suggest that breathing is the essence of hatha yoga training. It is much more fundamental than learning or mastering most difficult yoga poses or asanas.
Which breathing or respiration matters most? The breathing process is going on 24/7 and the body requires O2 all the time. Hence, it is necessary to have a closer look at our unconscious or basal breathing.
Classical manuscripts on Hatha Yoga (Gheranda Samhita, Hatha Yoga Pradipika, and Shiva Samhita) were written about 5-7 centuries ago. What do they say about breathing? According to these ancient hatha yoga manuscripts, the goal of hatha yog is to “suspend”, “hold”, “restrain”, and “calm” our breathing.