Friday, October 10, 2014

Marathon WR in Slow Motion: Dennis Kimetto Running Form

I do like an opportunity to watch elite athletes in slow motion. They make it all look far too easy!


Here’s a great video showing Kenya’s Dennis Kimetto in the closing few kilometres of running a World Record time of 2:02.57 in Berlin this year.



Some Observations


Clearly this is footage pulled from TV, rather than good quality high-speed camera footage. So we can’t get too into the more subtle areas of running biomechanics. But we can look at a couple of key areas…



Cadence / Stride Frequency:


Earlier the race, I picked a few of the leading group of male runners, and simply counted their cadence (strides per minute). As you’d expect, there was variation between the runners, but all those I observed were in the 180-190spm region. At the pace these guys are running, that shouldn’t come as a surprise.


What I found interesting is that in this footage collected nearly 41km into the race, Kimetto’s cadence is still well over 180spm. That’s over three steps per second – which you can observe using the race timer in clip! Anybody who has really pushed themselves in a race will know that cadence (leg speed) is usually one of the first things to drop as fatigue kicks in.


We can assume that Kimetto had to work pretty darn hard to set a new WR, which makes the consistency in his cadence impressive!


Remember though that cadence is variable in determining running pace, not a constant… more on that here and here.





Stride Length & Foot Strike:


The tongue-in-cheek title of Craig Payne’s article on this run made me smile:


Heel striking in a cushioned shoe with a 10mm drop and he still managed to break the world marathon record!


It’s important to remember that not all heel strikes are made equal. Also that there is a big difference between the glancing / proprioceptive heel strike we see from Kimetto, and the heavy, over-striding heel strike we see from many less skilled runners.


I’d also argue that on his left, Kimetto is heel striking a little more pronounced than on his right, which looks to be more on the borderline between heel strike and midfoot… Hard to say with this quality of footage through! This just goes to show how even the elites often display notable asymmetries in running gait.


“Isn’t he over-striding?”


That’s a question I’m often asked when people see elite distance runners and show surprise at how far ahead of their hips they strike the ground.


I’ve been guilty in the past of judging distance runners on whether they land close to under their hips / centre of mass, or not. Using this as a simple marker of whether they’re over-striding or not. This is unfair I now feel…


When working with sprinters, I do want to see them strike the ground as close to under their hips as possible when sprinting at maximal velocity. Marathoners are not sprinters!


When working with distance runners, the over-striding marker I now look for is whether the point of initial foot contact comes as the ankle is positioned underneath a flexing knee (regardless of foot strike pattern). What we don’t want to see is a more extended knee aligned behind the ankle as the foot strikes the ground – essentially running with the brakes on!


Kimetto achieves this ‘ankle under flexing knee’ nicely as the foot strikes the ground.


I’ll cover ‘markers for over-striding’ with reference to the differences between sprinting and distance running in another article :)




Feel free to share your thoughts on this footage in the comments section below…


The post Marathon WR in Slow Motion: Dennis Kimetto Running Form appeared first on Run Coaching, Ironman and Triathlon Specialists - Kinetic Revolution.






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