You explained how Bandhas protect by regulating blood pressure in Pranayama. Is there a virtue in practicing a technique, which may cause blood pressure to rise? Thanks A.
Main benefit goes beyond adjusting blood pressure. It is good for those with lowered pressure but more importantly helps to regulate heart function both subtle and emotional. With practice it can prolong the pause (kumbhaka) that leads to natural (sahaja) meditation. To me bandhas are the techniques for pratyahara; they can create a transition from Asana, pranayama into dharana and dhyana so that serenity and peace can be found as arising from within. This is a great attainment as we are so easily convinced that serenity consists in some outward attainment or activity.