I regularly train with a mate who has studied xingyi for longer than I've worn pants. When we spar he has an annoying way of having hands and arms so heavy I'd need a mack truck to move them, and yet this guy is 100 pounds dripping wet if that. I'm about 230 pounds.
My experience is mainly in Bagua and so I rarely if ever meet his force head on, but this intrigues me. He reckons he doesn't know how he developed this particular skill, other than always training with the intention to occupy the space in front of him. So my question to the knowledgeable Xingyi players is this: is that intention over decades of training what makes the Xingyi body heavy as hell? I haven't come across this in any Bagua or Tai Chi player, or any other Xingyi guy - but I reside in Australia so may be there aren't that many who know how to do it over here. Comments?