LAUSR

As sports enthusiasts and scientists, we were reminded of many important lessons on the day that Eliud Kipchoge set a new world record in the marathon. On September 16th, 2018, he ran a time of 2:01:39 in Berlin, eclipsing the previous record by 1 min and 18 s. Two days before the Berlin marathon race was to take place, our paper [1] was accepted, but would not be seen in press until a week later. On the day of the race, Kipchoge not only broke the world record, but he might have also broken the record for outdating a scientific paper. Note that for our simulations of cooperative drafting during marathon running, we used Kipchoge’s fastest marathon time (2:03:05 from the London marathon in April 2016) as a model input. Kipchoge’s new world record time suggests that since he is so much faster than any other current or historical marathon runner, he might not be able to benefit from cooperative drafting as we originally predicted. Kipchoge’s new world record time also suggests that we might be closer to a sub-2-h marathon performance than originally predicted. We based our ideas and model simulations on a snapshot of the current state of elite marathon running at that time. Nonetheless, new information brings about new understanding, a crucial aspect of the scientific process. While our previous predictions of possible marathon times are outdated with Kipchoge’s new world record, the most important insights of our original paper are still valid. We built a framework combining knowledge from the fields of biomechanics and physiology of marathon running, using fundamental principles that allowed us to understand how an elite runner like Kipchoge could exploit the benefits of cooperative drafting. We specifically simulated each athlete’s ability to tolerate intermittent exercise above and below their sustainable velocity (SV), with the goal of exploiting their D′ (D-prime, the distance capacity that can be covered above one’s critical velocity) to increase their overall marathon velocity. When compared to traditional drafting, our model simulations clearly showed that cooperative drafting allows elite marathoners to run faster by taking turns in the lead, allowing each runner to intermittently exploit the depletion and recovery of their D′ while sustaining exceptionally fast running speeds (refer to Fig. 1 in [1]). With Kipchoge’s new world record, we now have the opportunity to update our predictions, but more importantly, it allows us to test our model and cooperative drafting concept in a more extreme, but realistic situation where one of the runners is substantially faster than the others. In addition, we use this opportunity to assess how sensitive our predictions are to changes in D′, arguably our least certain estimate. Therefore, we follow up from our previous work by revising our model input parameters using Kipchoge’s recent world record performance to determine (1) if Kipchoge, being much faster than other elite marathoners, could still benefit from cooperative drafting and (2) how many runners with the physiological characteristics of a 2:01:39 marathoner like Kipchoge it would take to break the sub-2-h marathon barrier. * Wouter Hoogkamer [email protected]