The design of certified athletics tracks is tightly regulated, though there is some leeway. In principle, the inside edge of the track measures 400 m in total, with two opposing 84.3 m straights joined by two curves. The 100 m is run in a straight line; the 200 m, by contrast, covers half a lap, with competitors starting on the bend and finishing on the straight. Traditionally, each curve is a semicircle with a radius of 36.5 m, a path regarded as optimal for reaching maximum speed.
Two French mathematicians, Amandine Aftalion and Emmanuel Trélat, have developed a model aimed at determining the mathematically optimal shape for the track. It is based on the runner's oxygen consumption, which varies with the curvature. The two researchers showed that the traditional track is far from optimal. They propose shortening the straights to 60 m and increasing the radius of the curves to 44.3 m, thereby reducing the track's curvature and hence the centrifugal force. The gain would be around four hundredths of a second, equivalent to roughly 45 cm. Usain Bolt's record of 19.19 seconds, set in 2009, and Florence Griffith-Joyner's 21.34-second record, set in 1988, had better watch out!
