The sub 2 hour marathon: was it the man, or.. the shoe?

He did it!!

Kenya's Eliud Kipchoge became the first human to run under 2 hours for the marathon distance of 42.2 km!

And he did in style, smashing the historic barrier to finish in a time of 1:59.40.2


And almost as soon as Kipchoge crossed the finish line, the debate began..

was this a remarkable, historic feat of human determination, courage, and skill, or was it due to the bespoke running shoe, specifically designed and built by Nike, for one athlete and one event?

Eliud Kichoge and the INEOS 1:59 Challenge.

To try to get a sensible answer to this question, let's drill down on the information we have about this remarkable affair.

On April 28th, 2019, Kipchoge won the London Marathon in the second fastest time in history, 2:02:37.

This was later to be bettered by a stunning preformance by Kenenisa Bekele at the 2019 Berlin Marathon, where he went over in 2:01:41.

This was only 2 seconds slower than the World Record time, set by Kipchoge at the same race, but a year earlier, of 2:01:39.

With the exception of these two incredible times, the World record has hovered around the 2:03 mark.

Here are the 10 most recent best times


 And here is the progression of the World record time for the past 31 years 

world record.png

So, in 31 years, the World Record time was reduced by 5:11

Now HERE are the times for Eliud kipchoge for the entirty of his marathon career.


So, in the 6 years Kipchoge has been racing the marathon distance, he has reduced his marathon best times by 5:50.

Thirty nine seconds better than the entire time reduction of all marathon records for the past 31  years!!

Now Eliud Kipchoge is clearly a once in a generational runner, but equally clearly, it seems something else beyond isolated human performance is afoot (haha!) here!

To underline this, when we look at Kipchoge's marathon times across his career, the outlier, with the exception of the 2 experimental runs at Monza (Breaking 2) and Vienna (INIOS1:59), was the World Record set in Berlin in 2018 (2:01:39)

THIS time was 58 seconds faster than his next best effort.. the equivalent to the grand canyon of marathon time differences!

For this race, Kipchoge was also wearing an experimental version of the much hyped Nike Vaporfly 4%, the shoe that was to become the Vaporfy Next % with a touted 5% economic advantage.

If we then look at the difference between his times in Berlin 2017, and Berlin 2018 (were he set the World record), the differential is a massive 1 minute 55 seconds..

in one year... in a marathon!!

IF the shoe were offering a 4% advantage, this would equate to an almost 2 minute difference in times.

OK.. so let's sit on that for a bit and take a look at the shoe Kipchoge wore on the Hauptallee in Vienna..




 This... is the Nike alphaFLY and it was built specifically for the INIOS 1:59 Challenge for Eliud Kipchoge. 

What you are looking at iis akin to an alien spacecraft, there has NEVER been a racing shoe that comes even close to this.

For a wonderful breakdown of the shoe, go here

The highly influential and very balanced Thomas F. Neuberger from Believe in the Run, had this to say about the new shoe.

"First off, this sole structure is a cornucopia of Nike technology. If there ever was an example of maximalism in a shoe, this is it. The wording in the patent application literally refers to the outsole composition as a “plurality of plates.”

Broken down, this sole structure features four independent cushioning pods, three carbon fiber/polymer plate layers, two layers of midsole foam, and a partridge in a pear tree."

The midsole is comprised of four different levels: a top layer of foam, a second layer of composite material, a third plate layer (possibly carbon fiber), and a bottom layer of more foam (see the image below).

Aside from the very top layer of foam and its accompanying plate layer, the rest of the sole is fully segmented between the heel and forefoot, with a sizable void between the two, partially filled in by those two layers of cushioning pods.

The forefoot may well be where the magic happens here, becasue Nike have produced 2 version of the forefoot setup.

1. The "pods' are either “fluid-filled” , ideally pressurized between 20-25 psi.

These pods will have a series of vertically aligned of tensile fiber strands within them, presumably designed specifically to maximally return compressed and stored elastic energy. There is discussion over their shock attenuating abaility, howver I believe this would not have been the primary focus of Nike with this design.

This is what this version of the alphyFLY looks like


photo credit Believe in the Run

2. The second version is identical, except the fluid pillars are replaced with foam. Currently there is no clear picture to establish which version he wore in Vienna, but from what i can see, it looks like the foam version.

It looks like this.


photo credit Believe in the Run

So let's try to wrap it up.

Here is an excellent analysis from Professor Ross Tucker @Scienceofsport


"A ‘typical’ runner gets 4% RE benefit, and their time reduction is enough to turn a 2:03:00 into a 1:59:48."

Kipchoge ran 1:59.40 yesterday, so I cannot better this comment.

And on this basis, with all admiration for Eliud Kipchoge and what he has achieved, I think the major difference was..

the shoe


Simon Bartold
Director of Bartold Clinical