The speed of a runner benefits from minimizing contact with the ground, at least in contact time. For a car it may be contact surface reduction.
Running technique coaching and inflating tires, if taken to the extreme, leads to "flying" as the ultimate zero contact movement.
Early mornings walks to the Tel Aviv beach in March. Lots of joggers and runners committed to start the day bright, early, and sweaty. After two weeks of curious observation I made a mental note that the prevalent running style had lots of ground contact, true across all age and fitness groups.
Curious observation gives way to causality analysis. The only explanation at hand is that Tel Aviv runners develop their technique during their mandatory military service...and further assume that soldiers train with boots instead of Nikes, while carrying heavy loads. That would explain not picking up their feet like gazelles.
If you buy such evidence as proof, there is a lemma we can derive. We know that if you carry a burden, once the burden is removed, you will feel stronger and lighter. But carry a burden for a long time, and you will continue as though the burden is still there even after it is removed. The burden is in you now.