I had that once, in a sparring match during the training. When we where about to start, I already had some intense matches. So I was a bit out of breath, so I bent my knees a bit, and "tried" to do some kind of "chi gathering moves", I had never done that before, but after some of those "moves", we started the match, and it seemed like everything moved in slow-motion, I blocked every kick he made and was able to hit him wherever he opened his defenses But how is that possible and how could I do that again?