I've posted this before, but I am compelled, having discussed it recently, to do so again. It's the best photo I've had the pleasure of occurring in - which is specific phrasing, on my part. The dirt, rocks, lake, and sunrise are the stars here. I'm just a dude that happens to have happened upon the scene, at the right time. And not a dude, if we're picking nits, who ought to be chosen for any sort of running ad shoot, given my high and punchy arm carriage (it's always like that), flared elbow, swooping hair, knock-kneed quad angle, etc.
You can see here, after the same race, that my knees point inward pretty drastically, which could, theoretically, have all manner of deleterious kinetic consequences. But, I mean, you can also see that I won the race. Well, probably you can't see that, because you can't zoom in on the mug, and read the text. But I did win. Promise. Even though I think I look a little stupid while running, it seems to go ok, for the most part. But I am - and will remain - rather absurdly preoccupied with all manner of core/strength work. I don't think it's made me look any faster; but it has helped my times actually get faster, inasmuch as it's allowed a guy with probably pretty suboptimal natural biomechanics to train at consistently high volumes, without anything like an overuse injury. And highish volume training (for me, I'm calling this 70 and up, at present) - aside from being absurdly addicting - makes for better racing.
Which is the point, yeah? Works for Priscah Jeptoo, anyway.