According to UK experts, man is near the physical border in some sports such as athletics. XX. Since the beginning of the twentieth century, researchers have analysed the data of this sport and consider that records obtained during years are adapted to the curves in the form of S. That is, after a slow initial improvement, the brands improved very quickly at the time when the sport became professional. In the last twenty years, however, the improvement has slowed and athletes can be very close to the physical barrier.