Yes, I am Japanese...and you're Swede?
One of the biggest mistakes I made when I went back to Japan (the time before this New Year's) was not to pick up a book on Ma's runners. It talked quite a bit about their training and, I can't remember exactly why, I didn't buy it for whatever the reason. I really should have and, next time I'm back in Japan, I'll definitely look for it again (hopefully it's still out). It's hard for me to comment on how Chinese train because I really don't know and, the information out there by saying that they run 20~30 miles a day, I don't know the validity of it--I only take it for grain of salt; I've seen so much misinformation out there!
One thing I know is, yes, I guess they, both Japanese and Chinese, run a lot. It is probably because of their system and mentality that allow them to committ themselves to do so. They don't think too much of if it creates overtraining. They probably think more or less like Gerry Lindgren--if you want to be good, then you need to work hard at it; if you want to be better than others, then you need to work harder than others. Very simply thinking. Of course, that alone is not going to be a solution; they still put "some" thinking into it but they don't tend to use "science" as an excuse or permisson to train less.
I, as some of you know, was back in Japan mere a month ago. Most houses in Japan, as my parents' place, don't have the central heating system. My mom kept telling me, before I went, that it's been very cold (about 45~50F compared to MN's sub-30F). Well, my wife called me and asked me how the weather was in Japan. I told her that it's very cold...inside the house! She laughed (she lived in Japan for 3 years and spent one winter at my parents' place too) and said, "Go outside to warm up...at least you can get the sun!" They only recently installed the running hot water (thank God, now I can take a shower when I go for a run there!). But my mom still washes dishes with cold water--that's what she's used to. Hardship to some is nothing if you're used to it.
I'm not saying Americans are soft or anything like that. When you read Mike Salkowski's blog, you can see how he trained with his young family and work obligation. I used to get up at 4:00 just to get my long runs in because of my family obligation. It's the choice you make. I guess what I can say is that, here in the US, there are way too many choices. It's easy to say you don't want to get up early in the morning to get the mileage in; so you don't. What does bug me is that some people use that as an excuse to say, "Well, we can't run 100 miles a week because..." We don't hear too many of that kind of excuse in Japan...and I'm sure we don't hear that in China either.