One way to understand Qigong is that it is the basics or foundation of T'ai Chi. This is how I learned from the very beginning: grounded myself first in a Qigong form, then gradually learned the more sophisticated principles and practices of T'ai Chi.
Why Kung Fu? I have always enjoyed applying Kung Fu techniques to my riding. I believe that with of course strenth gained over the years is why I can drop other riders that by appearance one would think they could ride faster.