I had been practicing qi kung for health for many years, off and on. As much as health qi kung is different from martial arts qi kung as our limited knowledge tells us at this moment, I still suspect and strongly believe that they are transferrable. Example, when I first met Dan, I was trying to "show off" my qi kung to "impress" him and without more detail, he put me way way back in my place with his demonstration of what I was trying to do and he is a " martial arts" qi kung sensei as most of us would consider him to be. Hence my suspicion.
For me it's more than a suspicion. Solo training is required for acquiring internal power. I'm convinced that qi kung is an important part of internal chinese martial arts training that can lead to internal power as the existence of chinese grandmasters with power shows.
But it's also evident that very few students of those chinese grandmasters can do what their teachers can, even after many years of training as loyal students.
This shows that there is essential information about why and how to train what, that you need to get there. There aren't that many teachers who know and understand the essentials, who are able to demonstate and who are willing and able to teach everything they know, for real, without holding back. And even less who will teach it to westerners, even if they are most loyal students for many years.
(I think I'm almost quoting some of Dan's posts here)