I think I mentioned this before somewhere, but one of the exercises Tohei Sensei described in "Ki in Daily Life" is actually a breath/fascia exercise, although he doesn't say that clearly. Someone else posted the comment that Tohei attributed that particular exercise to Ueshiba Sensei.... that would make sense, since it is essentially a power-gung.
Regardless, it doesn't hurt people to look around. Ueshiba certainly did.... Aikido is founded on the Ki of Earth and the Ki of Heaven, the famous Yin-Yang dichotomy.
Would the following be part of the second phase of that exercise?
I do believe I have a copy of "Ki in Daily Life" at home, but I have no idea what edition. That's on the short list of "books I now keep hidden because too many copies have disappeared and I'm tired of replacing it."