An interesting side note to the breath training mentioned here -
as far back as 2008 Dan Harden insisted that there were breathing exercises in the Sagawa line (there are earlier examples, I know, but this is the one that came up first in search), in opposition to no small amount of sceptacism.
And when this article appears in current times - there is hardly a ripple of controversy. It's interesting to see how much things have changed.
Best,
Chris