Not just running, but:
I saw it first on the Disney running forum, but I can't remember who the OP was.
The marathon portion at the beginning always brings tears to my eyes. A fast athletic woman finishing in 3 something, then a more middle-of-the pack woman (she still beats me) finishes in 4 something. They are dressed similarly and if you're not paying attention, you won't realize its 2 different women. It brings it home: fast/slow, Olympian/middle-of-the-packer, young/old..., we're all runners and should celebrate our sameness rather than our differences. Which I think this forum is great at doing.
I've posted this before about this video:
DW is ready to axe murder me because when ever she says 'Good Luck' before a race, I respond with (I have it memorized!): 'Luck is the last dying wish of those who want to believe that winning can happen by accident. Sweat on the other hand is for those who know it's a choice; so decide now because destiny waits for no man.' DW sharpening axe.