I'm sure some of it is nutrition and increases in quality of life. However that doesn't explain the cultural phenomena of all the old ladies deciding on getting perms, dressing in fancy walking clothes, and getting big floppy hats.

They are still pretty spry though. In Korea some of the old Buddhist temples are on really steep mountains. Some to the point where you have to use ropes to help you climb a "staircase" cut into the side of a cliff. During this I got passed up by a bunch of halmeoni that were taking the rock face like a bunch of goats. I know at 95 my granny still walked a couple miles a day and was able to put both of her palms on the floor when stretching.