Not so long ago, the idea of anyone running an official marathon in two hours was the stuff of science fiction. But on the streets of Chicago, it became a dizzying reality as the Kenyan Kelvin Kiptum ran 2hr 0min 35sec to shatter the men’s world record. As the 23-year-old ran the final few hundred metres along Columbus Drive, he even had time to blow kisses and wave to the crowd. His time not only took 34sec off Eliud Kipchoge’s old best but was another staggering reminder of how much super shoe technology has changed the sport. Kiptum, who was wearing Nike Dev 163 prototype shoes, said he had not initially targeted Kipchoge’s old record of 2:01:09. But that rapidly changed towards the end of the race, when he ran the 22nd mile in an astonishing 4min 18sec.