I'm not quite on the level with what Michael was saying in the quote in Mark M's quote. But I think what Mark said in response is exactly the same thing I was saying a few posts up in this thread:
muscle contraction is specific mental task that is an important skill in conjunction with increasing
the intensity of the thing that responds to intent (the "qi").
In other words they may indeed be 2 different things that we focus on at the same time.