This is a weighty topic. When students first encounter the bones, they laugh. Bones don't make sense. I say:

"Bone Training is weird. You enter a strange and uncertain place. With gravity there is no Yin/Yang. How could there be when gravity does not vary? To separate meat from bones requires great and sustained efforts of mental transformation. Your body's state of bony separation never varies. Our expectations are what varies. At this time, to perceive bony cues is virtually impossible."

I have recently began to notice the qualitative difference between the light yi associated with movement and what I normally associate with "thought". With yi, it always leads to movement or change in the body. I feel like it could be compared to wind. Yi is wind when it it fills a sail and the boat is moved along. Imagination is wind as well but it's immaterial to the boat because the sail is not up and the direction is wrong.

I know I've noticed this before I got busy with moving but I was doing the 5 elements some more and I noticed that after I do it when I sit down my stomach feels different, maybe larger or full? Is this just related to increased blood flow in that region or something from the different pressures on the organs? I know sometimes you've said if there is a full belly feeling it can mean that you are disconnected. Is this indicitive or something positive or negative? Or just what happens from doing the practice?