This is exactly what I have been trying to tell you...
"The long run puts the tiger in the tank," does not mean that you will have a massive upper body.
Craig Virgin once said to me, "I ran my butt off." That is what he literally meant!
Americans are not willing to be ectomorphs, even the ectomorphs "want to get big." Therefore we will never win in distances above 1500 meters.
Chris Solinsky would have been better off competing at the mile because he was 6'1" 165" Perhaps at that weight and constant TRUE speed development he could have made it to the Olympics. I have said that on other threads.
Drew Hunter, Galen Rupp, Matt Centrowitz Jr., are very skinny kids. But are they as skinny as Mo Farah and the rest InWyo mentioned? Probably not.