I actually started practicing this around the time we started week one. I got interested in it, and Kouji said I could.
One of my biggest experiences with this meditation has actually come from that first week. A few days into it, I got to concentrating particularly well on the dantien. I had "found" it, and so I no longer use the poke thing (really, the sooner you can concentrate on the actual dantien, the better).
In concentrating that night, I got kind of absorbed in the dantien. Its "feeling" got stronger, and my awareness sunk into it. Not a literal "sinking," as much as the majority of my awareness was on the warmth of the dantien--my surroundings, my thoughts, and everything else did not matter at that time. Only the dantien. In this concentration, I simply breathed and observed. With my awareness centered on the dantien, I felt more energy, and I felt my energy move all through me, over me and round me. As I inhaled, I somehow ended up doing Bardons practice of Pore Breathing without intending to--that is just what my body did, it seems. And so, inhaling, concentrating on the dantien, I felt qi flow not just through my nose but through the entirety of my being as, not my lungs, but my dantien its self inhaled.
It was a very strong experience, which I am not sure I can accurately put in words. It only lasted a moment, and but my dantien was very strongly warm and tingly even into the next morning. Suffice to say, I think I did something right, and I have spent the rest of my time since trying to relax back into that state of concentration and relaxation. And, make no mistake, that is what it was--do not concentrate on the dantien so hard that veins pop. Relax, and simply be aware of the dantien. Focus your awareness, so that you are aware of nothing else. Then, just breathe. This, as I have found, is a very good way to practice dantien meditation.
Other than that, in the last few weeks, I have had a lot
more energy that I did before. And, I have noticed something about my hair. See, I was born with orange red hair, and over the years it settled into a sort of auburn--a very nice color between red and brown, almost like having natural highlights (and if you don't know what that is, read a fashion magazine!). But, over the last few years, it has settled into being more brown than red. Today, however, I have noticed that it is more red than it was last month. The "red" half of the red-brown mix is a little stronger.
Now, the shade of ones hair color changes based on many things, from sun exposure to vitamins and other things. I can't say that my hair is getting healthier because I am practicing qi gong. But...I haven't been practicing anything else different, so take it for what you will.