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You assert that:
"Last month's Chicago Marathon had to be shut down mid-race, because undertrained five- and six-hour marathoners couldn't handle that much time in the 85-degree heat."
While I understand that characterizing it thusly backs up your thesis, the reality is that the uncharacteristically (for Chicago in October heat AND humidity, combined (tragically in one instance) with bizarrely unprepared race organizers, who ran out of water very early in the race (almost immediately, from the sound of things), led to the questionable cancellation of the race.
As a high school English teacher, I'd give you credit for using what we call a concrete detail (CD).
But as a clydesdale and/or penguin (large and/or slow runners, respectively), screw you, buddy.