[cptvideo2]

There’s also a well-known affect on blood-pressure (lowering) that comes from the breath control that’s at the core of most meditation practice.

http://www.health.harvard.edu/blog/stress-raising-your-blood...

I don’t think that the cause of this is completely understood, but CO2 is a potent vasodilator. I’ve seen hatha yoga (physical yoga) practioners ditch hatha for prana-yoga (breath yoga) because they said it's a more powerful way to get to wherever yoga takes you.

[curun1r]

One small nit to what you've said. Breath control is core to yogic practices, as you've mentioned, but it is not part of most meditative practice. Meditation typically involves breath awareness, but specifically not control. The idea is to observe the breath as it is, not how we would like it to be.

[autocorr]

I'm not the OP, but it is an important distinction, breath control (pranayama) is yogic.

While I can't speak for other traditions that feature meditation, at least in Theravada Buddhism, training of the breath is an essential part of the practice for the development of mindfulness (sati), beyond "observing the breath as it is." This gets de-emphasized in the modern vipassana movement focusing on "bare attention", but canonical interpretations of the Anapanasati Sutta [1] on the mindfulness of breathing to indicate that one only uses bare attention to "discern" long and short breaths, but "trains" oneself to become aware of the whole body, to calm bodily fabrication, and the rest of the items on the list. This is taken to mean that one can use right effort to breath in ways that are conducive to being aware of the whole body or ways of breathing that calm bodily fabrication, etc. So, while definitely not as gross as counting fixed durations like on the site linked, exerting oneself to influence the breath has a place in at least one very prominent non-yogic tradition.

[1] http://www.accesstoinsight.org/tipitaka/mn/mn.118.than.html (perhaps the second most important sutta related to meditation in the Pali Canon, next to the Maha-satipatthana Sutta [2])

[2] http://www.accesstoinsight.org/tipitaka/dn/dn.22.0.than.html

[thomyorkie]

And yet another nit must be picked. Breath awareness is simply one way to meditate. There are a broad array of different meditation techniques and some do involve breath control.