Title text:
Runners looking for aerodynamic advantage typically wear sneakers because some fancy dress shoes can create wingtip vortices.
Transcript:
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Source: https://xkcd.com/3305/
Top performing sprinters accelerate faster that 1g, so slightly increasing the gravity would probably make them faster on very short distances.
For long distances it would probably be some low gravity jumping limited by the relative speed between foot and torso that you can create before touching the ground and decelerate before overextending the leg.