It does not play any significant role. That you can hold breath after exhaling is obvious and yogis probably talked about it. Doesn't change the fact though that Pranayama is all about holding breath after inhaling. That is basically the core goal.
okay, I'll have another look at it. anyway - my intention was not to disregard breathing techniques where breath holding after exhalation plays a role. I do a few of them on a regular basis. I just don't like the Navy Seals practice Pranayama sentiment. can't even say why exactly.
