Here's a brief wsj video: https://youtu.be/Bp9km7oRtmU https://youtu.be/Bp9km7oRtmU Some notes: * That's mostly national team people in the video * All of t

Here's a brief wsj video: https://youtu.be/Bp9km7oRtmU https://youtu.be/Bp9km7oRtmU Some notes: * That's mostly national team people in the video * All of the yelling is after the action stops * As you'll see, the primary reasons stated are to mess with the opponent's head, and the ref. And then stress relief, yea. You'll do other things like, uh... stabbing your own foot... for that purpose as well. (Sounds bad to say out loud but it doesn't hurt) Akido (and kendo too) are a lot more stylized. Some yelling in there is for the same reasons, but a lot of it has been passed down in some almost mystical level. It's not a hyper optimized/gamified sport that cares only about results, so you get a lot more style points type things happening in aikido/kendo/etc. gamified - as an example, there was a period of time from like late 90s to early 00s where foil fencing became dominated by an offensive strategy that involved literally bending the blade and hitting your opponent's back. It got so ridiculous that they messed with the weight/timing on the electronic equipment so it didn't work as well. And in the later 00s people started using plastic chest protectors because with the new timing, you'd get some attacks literally bouncing off your chest protector and not registering. Just kinda a ridiculous results-only-everything-else-be-damned situation lol.