Like it or not, there’s a much avoided phenomenon in the evolution of speed sports . The world records in running tend to be set by black athletes, while world records in swimming tend to be set by white athletes. This phenomenon is backed up by simple physics. Locomotion is a “falling forward” cycle in which body mass falls forward and then rises again. Mass that falls from a higher altitude falls faster, downward and forward. In running, the altitude is set by the position of the center of mass above the ground. In swimming, the altitude is set by the upper body rising above the water, and it’s proportional to height minus altitude. The center of mass in black athletes is 3% higher above the ground than in white athletes. This means that black athletes hold a 1.5% speed advantage in running, and white athletes hold a 1.5% speed advantage in swimming.
