I've experianced this in sparring match's back when i first began and would forget my breathing. After taking many hits to the ribs (One of the benfits of training with black belts when i was still learning how to spar) I would find myself crouching and having shooting pains from lack of breath, and kicked ribs. But i noticed that once i began blocking one punch, then a kick, then another the pain began to go away, and my movements quickend. Afterwards however
it HURT!
Couldnt this also be attributed to Adrenaline? If you've ever tasted that on the tip of your tounge you know what i mean.