Earth rotation and running speed

Yep, a "pound" could be pound-force (lbf) or pound-mass (lbm), and it wasn't specified so I can assume that it is lbm.

The longer you can stay suspended above your frame of reference the more effect there would be.

Picture being on a rotating earth - facing the direction from which it rotates. When you are standing there you are moving the same speed as the running surface - even though you think you are both standing still. Every time you come in contact with the earth you return to the speed of the earth. But if you are bounding when you run, there are greater periods of time in which the rotation of the earth are not impacting your position and speed relative to that earth. So if you are running opposite the direction of rotation, the longer you are in the air the faster the earth will slip by beneath you. It will appear you are running faster.

Since the earth rotates faster than you can run, if you bound in the direction of rotation the finish line keeps spinning away from you when you are airborne. If you bound high enough you would never finish the race.

I always coach my freshmen to "bound toward the rotation, take short, low steps with it."

I also plan meets around the earth's rotation. Early season it doesn't really matter where you run. Late season when you are trying to set records it is clearly adventageous to run in the Northern Hemisphere.