While qi-gong,
tai chi, and yoga are nice to do, none are meditation.
Tai chi is slow motion kung fu. It's a martial art requiring great concentration, and sure, concentrating hard on something crowds out other things, but it isn't meditation. Many tai chi classes or groups do meditate a bit after working out, but like yoga, it's hard work. Qi-gong are just warm-up exercises, again, not meditation.