The subject of Qigong is a difficult one to come to terms with on many levels though we live in a time in which it has become very popular again, both in the West and in China.
I won’t try to summarize any aspect of this exercise/meditative umbrella of practises except to say that many taiji teachers have said that our discipline is not a form of qigong and that such supplementary exercises are not useful to developing any of the six Family styles of taijquan and their attributes.
One of the exceptions to this is the practise of standing quietly for extended periods of time [5-30 minutes] before and/or after doing any of the traditional Yang solo forms. Since I am, foremost, a Yang style practitioner, I will let one of the acknowledged masters of that art voice his opinion on this from "The Essence and Applications of Taijiquan" by Yang Cheng fu  , translated in 2005 by Louis Swaim and published in 2005. It summarizes neatly the Yang Family approach to standing still as being an integral part of learning and practising that discipline
I had some sad news yesterday when a former taiji colleague phoned to let me know that she had recently learned that our first taiji teacher, Shirley Choi, died in April of this year. While I had lost touch with the deceased since the late 1980s, I owe her and her late husband, Steven, a great debt as my first serious instructors in the Yang style. I had first learned rudimentary taiji at a three-month course in 1975; however the instructor didn't offer another session after the first one finished. I learned about Shirley's classes from a couple who had been in that course with me and who were more in tune with the local taiji world, and went to watch one of Shirley’s classes. I was hooked even though Shirley focused on Yang style for health and I was looking for a more martial approach.
43+ Years of Experience Training in the Chinese martial arts; 33+ years experience teaching taijiquan and 24+ years experience teaching baguazhang