Upvote:1
The breath patterns you are mentioning (2s-4l-2s breath sequence (s-short, l-long) followed by 2s-2l-2s
) is generally found in Yoga / Pranayama than in Theravada Buddhism.
Nevertheless, Anapana Sutta does mention about the long and short breaths. The breath is considered a bodily fabrication and it is tied to the body. (If you stop breathing then you are dead.) In meditation you have to calm your fabrication, out off which the bodily fabrication generally cease before mental fabrications. As you get concentrated your bodily fabrications also slow down hence shorter breaths. When you come out of meditation your breaths become longer as you start creating fabrication. If you start thinking and pondering (verbal fabrications) again your breath becomes longer as these fabrications influence bodily fabrications.
Kamabhu Sutta, Culavedalla Sutta & Rahogata Sutta covers more on the 3 fabrications out of which bodily fabrication is tied with the breath and breathing process.
Upvote:1
In Katsuki Sekida's book Zen Training - Methods and Philosophy, the author talks about bamboo breathing. Essentially, the way the practice works is that you exhale in smaller, segmented breaths much like in the way a stick of bamboo is segmented. This has a couple of applications, specifically for Zen.
First, Sekida states that bamboo breathing helps build "internal pressure". That's a phrase he invents in the book, but the way he uses the terminology and the phenomenology he attaches to it makes it sound an awful lot like mushin. I'm personally not a fan of using his method for emptiness meditation - I think that a single deep, natural abdominal breath is better - but he seems to have some success with it. I think his main reason for employing this technique is to maximize the time the body is completely stable. In the conventional way of a single breath, you only get that space of pure nonaction (i.e. not breathing) at the very end of the breath prior to inhalation and to a lesser degree before exhalation.
Second, and I'm in more in agreement with Sekida here, he applies this type of breathing to working with the turning phrases of koans. For instance, say you were working with Nansen's cat. Your exhalation pattern might be segmented along the lines of "Kiiiiiiillllls [stop] theeeee [stop] caaaaaaat". Again, I'm not sold on it, but it does make sense.
Sekida actually does a lot with breathing in his book. I mean, the dude spent almost sixty years watching it so he does have a lot to say on the subject. He even brings in ideas like lung capacity, recovery breaths, etc. etc. If you're interested in the place of breathing from a Zen perspective, his book is worth a look.