Tucker wrote:
Yes, though it’s probably better to word that subtly differently - smaller athletes are less affected by the heat and so they perform relatively better than large runners on hot days! As for cold, rainy weather, same question crossed my mind when I saw your weather article!
In cycling, it was thought that larger riders, with slightly higher body fat %, would be less affected by cold. Same is true for cold-water swimmers - if you wanted to swim the English channel, you needed insulation from higher body fat %. So the same logic suggests that runners with very low body fat % will struggle in the cold. Bigger athletes produce more heat, too at the same speed. So my prediction would be that in extreme cold (& the wind & wet achieves this for Boston), very small, lean runners will struggle more.
A final factor - does the athlete train in it. The Africans will find it entirely unfamiliar. Some Americans, too. But some will be accustomed. That said, I recall Cheruiyot won a super cold Chicago, so predictions only go so far!
The mitigating factor is that the elites generate such a large amount of heat because heat production = 4 x mass x velocity. The slower runners at the back are going to struggle, especially if it’s wet (heat loss in water is 25x greater than in air). Staying warm is a big issue!