I can say this at least - anytime I'm at a national park in Korea, the older people walk circles around me in terms of hiking. they don't play around. it seems they are always helping me up...
Now in America, there's no way you'd see my dad on the floor for anything. If for nothing else, cultural necessities step in and demand that he use a comfy chair. Even though my mom is in great shape, I would guess that she would even get tired of sitting and raising from the floor; which brings me to my theory. If one always does things a certain way, one gets used to those ways. Perhaps it's not as big of a deal for Koreans for two reasons. 1) comparatively speaking, the whole world (including Korea) is more physically active than most Americans and 2) if Koreans are always raising and sitting on the floor, perhaps those muscles involved are in better shape than than people in the west.
(in case anyone is wondering what blog entry we're talking about - get with the program here: http://blogs.koreanclass101.com/blog/20 ... angements/