At least a couple of times in the recent past, including at NCAAs, Mike Smith has referenced running form changes that have positively impacted Nico Young's performances. He started to add some detail to this in his Letsrun.com interview after the successful double, but I think he said, "it is complicated." Smith mentions that difference between easy running (your foot falling to the ground) and fast running (applying force to the ground) but leaves it at that.
I have noticed a difference in Nico's mechanics from, say XC Nationals 2022 to now, but it is pretty hard to describe that change.
(Side note: Regarding the application of force into the ground, the most recent study I've seen indicates that more force is actually applied to the ground when one focuses on lifting the opposite leg than driving the stance leg downward.)
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