Some people have raised some interesting points about Japanese and Chinese athletes. I have some questions, just to inspire some debate:
1. What about Americans of Asian descent? I myself am one, and ran track in high school and college. Asian Americans only constitute 5% of the population, of course, so that tips the balance in one way. However, I went to a high school school with a strong running culture, in an area with a relatively large Asian population (~25%), and at least anecdotally found it rare to find top athletes who were of Asian descent. Some may point to cultural differences still, and they may have a fair point, but of my friends who were Asian, most were very into sports of all forms (tennis, track, football, basketball, etc), so at least in my urban area, Asian teens were certainly into sports frequently.
2. There is a relatively large amount of data indicating that, on average, Asian adults are shorter than Caucasian adults. I wonder if this might be the *only* physical bias that predisposes Asians away from certain sports (e.g. football). In other words, is there any evidence to suggest that if two men were both 6-1, 180 lbs, but of different ethnicities, one would statistically tend to have more raw strength (by some objective measure, such as max squat weight)? I doubt any studies have been done, but it would be interesting to see people speculate on this.