Hi Marcy,
I hadn't heard anyone mention chills before, to the degree you did. Chills, tingles, heat, whatever, experienced during or within close proximity is one thing, chills for eight hrs seems like another. Again, regardless, level I active is very effective for self healing, and that is really all one has to know. You can back off it, or modify how you express it, if there are limitations or discomforts. Side effects, the same thing. Do what you are comfortable doing, and listen to your own body as you proceed. By all means, proceed though...
You are obviously self aware and sensitive, so enough said.
Regarding standing or sitting...
It is the simple idea of building and storing or using energy.
If one is depleted, a more demanding physical position or posture, would work against building energy. For some people, that could be as simple as standing, as opposed to sitting. Also, excessive sexual activity would tap the same energy reserve. Getting enough rest, eating properly, etc...
In qigong, you have this internal reference to three dan tiens. In level I, there is emphasis on the lower dan tien, and emphasis on 'physical' healing. Relative to a meditation practice, my own sense is that building the lower dan tien, grounds you and strengthens the 'container', that then can handle higher energies. So establishing that center, then moving up to the heart or third eye center, is a beneficial progression, whether within one meditation, or over time, in a general sense of paying attention to that lower center. As I said, I think many people bypass developing those roots, and go directly to the third eye center. The lower dan tien maybe seeming mundane by comparison to what one feels in the heart or sees in the third eye.
In level II there is a shift to focusing in the heart center. Also, there are heart centered meditations utilizing mantra, that some people learn at retreats. They still start and finish in the lower dan tien, and relative to a heart centered practice, one still shifts to taking care of the body and perhaps more lower dan tien focus, if physical issues come up. Not that level II healing techniques don't work to clear something. I refer more to how one engages with active exercise in one's practice. Maybe a dip in physical health most likely finds one using both those level II techniques, and level one active. That is one aspect of balance that one finds in this practice. I certainly don't deny that it is possible to 'transform' all aspects of self in a heart centered focus(I refer many to just a meditation practice), but I do feel that some people with physical issues, and that relative to their spiritual level of practice, in say a practice focused just in a higher center, may have difficulty in that transformation of physical blockages. Some not. It is all relative. I think it is wonderful to live a healthy physical, emotional, and spiritual life, experience and include all those pieces. It is a very simple and effective measure, and reference to self, through these three dan tiens. Where one is relative to them, where one can choose to reference oneself, express's one self, relative to these three centers.
Perhaps the lower dan tien will be a great puzzle piece for you given your past meditation practice., which I would continue by all means.
Bring into that practice, the starting point, which you could spend more time in to feed the physical self, and making the energy pill at the end, closing with the face washing, combing the hair, cupping the head, massaging the ears, and cupping the kidneys. Stand, and pat the tailbone. All this putting energy back in the right places and promoting health.
one more thing. Small universe can be quite elegant.. In the beginning, it can seem to have a pace to it that seems counterproductive to experiencing emptiness. At some point , without the CD, maybe try slowing it way down and expand the sense you have of an area, the area perhaps being the 'only place you are aware of ' in that moment of experience, not focusing there, relative to also seeing or realizing the whole loop, or other parts.
love,
gallen