don't know. haven't figure out what folks defined as ki/chi/khi/.... in asia, those things usually associated with gas, as in, by product of bean and cabbage (kimchi - pickled chi/ki with hot chili peppers (ooohhhh yyaaaa) - worked pretty well too). so here i am scratching my head and wondering what in the god name are you western folks talking about developing!!??? you just eat the stuffs and wait for a few hours and voila! c'est la vie!
By now you should have figured out that in the west, "ki" is the proverbial Emperor's Suit of Clothes. It is something I have and that you don't, something that makes me superior to you. It is proof by definition. Ki, and the concern over it, and the worshipful belief in it, and the hook-line-and-sinker swallowing of claims about it, probably do more harm to martial arts practice in the West than anything else. Mind you, there may be some thing called "ki" that is more than the end product of a bowl of beans...but if so, it's very much being overshadowed by the foolishness committed in its name.