Bryan Walker wrote:
It may annoy some of your trainging partners, but a good kiai when taking a fall will help you to keep breathing. Once you have confidence and control over your breathing you could eliminate the vocals. Many striking arts encourage kiai when taking a hit to keep the core tight and to keep you breathing through and beyond the attack....amongst other reasons.
just a suggestion
I have been doing the kiai when falling down thingy and yes you are right, it actually makes you last longer in jiyu waza/randori... I guess it all boils down to breathing.