If you have been following all the propaganda and rhetoric of recent years, then Dennis Kimetto should not have been able to run 2:02.57 to knock 26 seconds off the world marathon record a few days ago in Berlin … go figure! I have held off for a few days from commenting here (been busy commenting on Facebook though!) waiting to see the response in social media and the blogosphere to this run.
There has been plenty of good analysis on his run; for eg see Roger Robinson’s account at Runners World, so no point litigating those issues again.
Of relevance to this blog here are 3 points I want to raise:
He did this heel striking (see his images at Photorun.net). All the rhetoric and propaganda from the fan boys, running cults and bandwagons is that heel striking is evil and uneconomical. If it is so bad, how come Dennis Kimetto was able to run as fast as he did to break the world record? We already know that plenty of elite runners heel strike when running fast. Plenty of other elite runners also forefoot and midfoot strike when running fast. We know from the plethora of running economy studies that some have shown that heel striking is more economical and some have shown that midfoot/forefoot striking is more economical. What is obvious from all that research is that the best foot strike pattern for running economy is probably subject specific. There is probably no one systematic best foot strike pattern. If anyone is to claim that heel striking or midfoot/forefoot striking is more economical, then they are making it up and guilty of cherry picking. Obviously, the heel strike pattern that Dennis Kimetto used was probably the most economical for him.
POSTSCRIPT: I based the claim that he was heel striking on photos at Photorun.net and some that they have but have not listed yet in which it appeared that he was heel striking. Now I have seen the video below from Berlin in which he is clearly midfoot striking, so the above comments need to be interpreted in that context (BUT, the comments below still stand!).
Dennis Kimetto did his world record run in cushioned shoes, the Adidas Adios Boost 2’s (with Adidas’s Boost technology for cushioning and energy return). According to the fan boys, running cults and bandwagons, cushioned shoes are evil. The second place runner at Berlin, Emmanuel Mutai, who’s 2:03:13 was also under the previous world record was also wearing the Adidas Adios Boost 2’s. In fact, the five fastest marathons ever run have been done in the the Adidas Adios Boost’s! Obviously there is a sponsorship deal in place with these athletes, but they could all run pretty fast in a shoe that is cushioned. We have all seen the prediction that I addressed here that the first 2hr marathon will be run barefoot. Given that the fastest guys are wearing a cushioned shoe (and no barefooter has yet gone past 2:15), it is looking less likely that this is going to happen. In my discussion of the 2hr marathon, I discussed research that has shown cushioned shoes are more economical than barefoot, but also noted the subject specificity of that research. I also commented on the prediction that the 2hr marathon is more likely to be run in cushioned shoes that has the amount of cushioning tuned to the specific individual to get the subject specific response right (and in some that might be no cushioning). Presumably the Adidas Adios Boost 2’s have the right amount of cushioning and energy return specific for Dennis Kimetto.
10.4mm drop (forefoot/rearfoot differential):
The Adidas Adios Boost 2’s have a 10.4mm drop and according to the fan boys, running cults and bandwagons anything other than a small or zero drop is evil, yet the five fastest marathons ever have been done in a 10.4mm drop shoe. I previously reviewed the evidence for a specific drop in a running shoe; there was no evidence and all that was driving the concept of zero drop was the use of the natural fallacy. That does not mean that there was anything wrong with zero drop, but neither does it mean that there was anything wrong with a 10mm drop either. There really can’t be anything wrong with a 10mm drop if such fast marathons are run using a shoe with it. I speculated in that discussion on drop that the best drop is probably like the foot strike pattern and amount of cushioning – it is probably subject specific and there is no systematic best drop for all. Presumably the 10.4mm drop in the Adidas Adios Boost 2’s was the right subject specific drop for Dennis Kimetto.
As always: I go where the evidence takes me until convinced otherwise, and the anecdotes of the five fastest marathons is not data, but what they did can be interpreted in the context of the evidence and be used to poke fun at the fan boys, running cults and bandwagons.