Optimising Drafting When Running
by Doug Stewart
When Eliud Kipchoge broke the 2-hour time for the marathon, part of his success was attributed to a team of support runners that allowed him to draft them – reducing the air resistance he experienced. A recently published paper explored the positioning of the pacers to see if it was optimal, or if a different configuration would provide even greater time savings.
Eliud Kipchoge at the end of his record-breaking run in Vienna © The New York Times
Using scale models of 1/10 in size and a wind tunnel, the researchers tested various configurations to assess the impact on the ‘Kipchoge’ positioned figure.
Initial Configurations as used with the distances in cm and the orange dot representing the protected runner. Source Marro et al., 2023
After testing the formations as shown above, various others were trialled and refined:
Source Marro et al., 2023
Overall, it was found that configuration 8.1 was the most beneficial formation in terms of reducing drag. The researchers estimated that the Ineos 1:59 challenge saved 3 minutes 33 seconds versus Kipchoge’s World Record run set in Berlin without a lead-out of runners to draft from. However, formation 8.1 would provide an estimated saving of 4 minutes 22 seconds.
Source Marro et al., 2023
Based on the models used in the wind tunnel and the researchers’ modelling, we can infer that a faster time could have been achieved with a different formation in place. It is worth noting, though, that drafting will reduce cooling of the protected runner, which may negatively impact performance. Moreover, this study was using static models in a wind tunnel, which is obviously different from real world conditions. However, this research does provide some insights into how future record attempts may be set up to look to further optimise the use of drafting.
References:
Marro, M., Leckert, J., Rollier, E., Salizzoni, P., & Bailly, C. (2023). Wind tunnel evaluation of novel drafting formations for an elite marathon runner. Proceedings of the Royal Society A, 479(2276), 20220836.