They just said this on the international feed of the Doha DL broadcast.
Pretty interesting. When is the last time a major marathon was at night? I know the body's rhythm is such that runners do better at night than during the day but the heat will take away that advantage in Doha.
Rome Olympics was at night.
I've heard one guy say that if Breaking2 was at night that Kipchoge would have had a better chance of sub 2.