Looking at the comments above, it's actually pretty funny. In the western fashion, 14th Century German Longsword Fencing became the basis for most, if not all, modern western martial arts. Yes, even things like boxing and MMA. Just look at the footwork.
So if you knew German Fencing (which actually had a good bit of wrestling), you'd have learned a damn practical style.
Hopefully you never have to experience a real sword fight because there is a good chance you will get maimed, blinded, or killed. That being said, if you find yourself in a sword duel, and you are skilled in Kendo and your opponent isn't, and he's just wildly swinging a sword at you, then you may be able to counter his wild swings with carefully calculated blocks, parries, slices, or stabs.
Kendo has the same relationship to kenjutsu (the fighting art) as Western sport fencing does to actual duelling.
It's a sport, with very strict rules, a limited target area, and a light, split-bamboo "sword" that is not handled in the same way an actual katana would be.
So in short... No. Almost no relationship to the combat art at all.
Shinai and Shinken are worlds apart. Unless you train with a real sword, or at least with the proper weight, distribution and shape, you have little experience to back up any skills you've developed. It would be like swimming in shark-infested waters -- swords kill, and unless you're prepared for it, getting smacked with a bamboo pole is far from the penalty of making a mistake real sword combat involves.
Where do people actually fight with swords today?
It is extremely unlikely.
So, my answer is no.
J, also brings out some very valid points.
I don't think anything is practical about a sword fight anymore these days.
Depends on if you can block or deflect enemy weapons using a shinai or whatever you got.
