Cornell researchers: Vaporflys improve men's times by 2.1 to 4.1 minutes in marathon, women improve between 1.2 and 4 mins

889 wrote:

To think that new shoes do not help in the marathon is like saying new clubs and balls don't help in golf. But if you never played golf, you would never know.

So how does a new golf club help you run faster? Oh, right - it's a silly analogy. I might suggest new shoes in golf or new tees might be a more appropriate comparison - and would make very little difference. But I would be guessing - like you.

Armstronglivs wrote:

889 wrote:

To think that new shoes do not help in the marathon is like saying new clubs and balls don't help in golf. But if you never played golf, you would never know.

So how does a new golf club help you run faster? Oh, right - it's a silly analogy. I might suggest new shoes in golf or new tees might be a more appropriate comparison - and would make very little difference. But I would be guessing - like you.

Ok, are pros playing with balls and clubs they made in the 60s, or are they using new tech that is more forgiving and longer?

All you have to do a side by side and you would take the new clubs and balls hands down. All the senior players use new clubs and they played with the old stuff. It's longer and more forgiving, allowing them to keep their distance up.

Same way with shoes get a new pair of carbon plated shoes and go for a long run. Then go for a long run in your traditional marathon racing shoe. See which one allows you to run faster and are more forgiving. This could be any of of the new shoes by Nike, Saucony, and Adidas.

Long distance racing times have dropped like a rock since these shoes. It's more than just hype tp sell shoes.

Dr. Klein has a good article here:

889 wrote:

Ok, are pros playing with balls and clubs they made in the 60s, or are they using new tech that is more forgiving and longer?

All you have to do a side by side and you would take the new clubs and balls hands down. All the senior players use new clubs and they played with the old stuff. It's longer and more forgiving, allowing them to keep their distance up.

It should be pointed out that while everyone benefited from the new golf technology, some people benefited more than others. A different set of winners and losers came about as technology changed the game.

What I would be interested to know is how much gains can be had by tuning the shoes. If the performance increases vary from 0-10% with off the shelf models, what happes when they can go into the lab and mess around with stiffness for an individual runner? Can they get more people up towards 10%?

And would anyone else love to see studies of the rest of the random shoe techs? What did those airbags nike used do? Or asics gel? Any of the foam variants?

I would think that is the same with shoe tech- at least for longer races.

I bet that is coming next-at least for pros. Probably everyone has the perfect combo of foam and plate/rod tension for their running game. Just like in golf you can be fitted for shaft length, flex, flex point, degree of launch angle, and ball trajectory, for your swing.

A lot more money in golf than running, so the trickle down effect has now made everyone to get fitted for a price.

joeguinness wrote:

In our dataset, there were 71 men and 56 women who switched shoes from a non-Vaporfly to a Vaporfly shoe. However, the other people in the study are helpful for sharpening the estimates of the vaporfly effect.

Here's an example, suppose that runner A and runner B both run Boston and Chicago in the same year. Runner A wears non-Vaporfly shoes in both races, but runner B switches from a non-Vaporfly shoe in Boston to a Vaporfly shoe in Chicago. This gives us a piece of information about the effect of the shoes because we can compare how much runner B (the shoe switcher) improved in Chicago relative to how much runner A improved.

The gist of our analysis is combining a bunch of these mini comparisons in an optimal way, using a technique called generalized least squares.

How did you control for confounding by genuine improved fitness over time? Most runners improve over time, or at least that is the general idea.

If you followed a group of sub-elites in the 00's, you would have similarly found that brightly colored shoes (new models) were associated with improved performance compared with white-colored shoes (old models), since runners naturally improve and also switch to new models.

joeguinness wrote:

Hi Rojo, I'm one of the authors of the study and can answer any questions you or anyone else has.

We put the code and data online here:

https://github.com/joeguinness/vaporfly

One of the nice things about the researchers.one publishing platform is that experts can read the paper for free and leave their feedback, comments, and suggestions. We'd love to hear from runners and coaches.

If it is between 2-4 mins how come Kipchoge only improved by 1:26. He ran 2:03.05 in 2016 before carbon Vapofly shoes

Also what were the comparison shoes worn?

As the comparison shoes are not listed I'd assume it very unlikely the runners were wearing the fastest non carbon models hence the exaggerated difference.

ukathleticscoach wrote:

As the comparison shoes are not listed I'd assume it very unlikely the runners were wearing the fastest non carbon models hence the exaggerated difference.

Were there fastest models back then? Was there a noticeable difference between wearing asics 70z racer and nikes 7oz racer? Maybe the difference in 2004 between Baldini and Meb was the shoes. And lets not talk about track races where the difference is often a couple seconds. The supershoes are good enough that we can no longer ignore the difference equipment makes in running.

ukathleticscoach wrote:

If it is between 2-4 mins how come Kipchoge only improved by 1:26. He ran 2:03.05 in 2016 before carbon Vapofly shoes

Also what were the comparison shoes worn?

Kipchoge “improved” by 2:21. His fastest marathon prior to the shoes was 2:04:00 in Berlin 2015. He won London 2016 in the first prototypes of the VaporFly (same ones Rupp wore at the trials that year).

One should also ask: is it possible that Kipchoge declined between 2015 and 2018, and the benefit is even larger than 2:21? Or the opposite, that he improved and it’s smaller? I’d hedge on the former given his age and general trends of marathon asymptotes in two-a-year elites, but if there was one to break norms, it’d likely be him.

rojo wrote:

Anyone know if this study is well regarded? I just saw a link to it on TFN and haven't had time to look into it.

https://researchers.one/articles/20.02.00005

Hey Rojo just glancing through and instantly realised that this study may understate the gains of these shoes (or similar shoes such as the Adizero Adios Pro or Saucony Endorphin Pro). The researchers focused soley on sub 2:24 guys but they are likely closer to meeting their maximum potential and are likely to already have stronger lower limbs. It's the guys going from 3:10 to 2:49 that are receiving the greatest benefit.

ukathleticscoach wrote:

joeguinness wrote:

Hi Rojo, I'm one of the authors of the study and can answer any questions you or anyone else has.

We put the code and data online here:

https://github.com/joeguinness/vaporfly

One of the nice things about the researchers.one publishing platform is that experts can read the paper for free and leave their feedback, comments, and suggestions. We'd love to hear from runners and coaches.

If it is between 2-4 mins how come Kipchoge only improved by 1:26. He ran 2:03.05 in 2016 before carbon Vapofly shoes

Also what were the comparison shoes worn?

His 2016 shoes had carbon plates and pebax foam. Nike called them the "Mayfly." Rupp & Co had had the same shoes for the US trials and researchers found them to be way better than all shoes on the market. If Kimetto had of run in the adidas equivalent the Adizero Adios Pro he would still hold the Marathon record.

lobster wrote:

2.1 minutes as the minimum of the improvement range seems kinda crazy.

The vapor fly was pretty widely adopted by 2018 yet only Kipchoge managed to break 2:04, and the average top 100 time was well within the standard range for the last decade (and slower than some other years like 2012). 2018 would need to be by far the worst marathon ing year in the last decade for a 2.1 minute typical improvement to make sense.

2019 was significantly faster than 2018 (which is still weird considering the vapor fly was already popular in 2018. Are the next% significantly better?), but 2.1 minutes is still kinda pushing it even then. You still have second place at 2:04 high after the adjustment, which isn't unheard of (this occurred in 2015, but 2015 was the worst marathon ing year this decade) and the top 100 times were close to 1 minute better than usual, not 2.

1) I don't necessarily agree that the vaporfly technology was"pretty widely adopted by 2018". The Vaporfly was only unveiled in 2017. When Kipchoge ran 2:00:25 that year, everyone thought it was primarily because he was drafting off of a car - not the shoes. Rival shoe companies didn't even have prototypes of anything like the Vaporfly so many top pros couldn't wear anything close to it. To me, it would make total sense that 2019 would be way faster than 2018.

Also 2.1 m inutes makes perfect sense. The reality is Kipchoge isn't much better than Haile G.

Kipchoge raced in 6 marathons before the Vaporfly tech was used and never broke 2:04:00 (and actually that 2:04 was a vaporfly prototype but the insole was coming out). His 2:04:00 in Berlin was nearly identical to Haile G's old WR. Then he started wearing the Vaporflys and rarely ran slower. Add 2.1 minutes to 2:01:39 and you are getting something very close to 2:04 flat.

Burnsy wrote:

ukathleticscoach wrote:

If it is between 2-4 mins how come Kipchoge only improved by 1:26. He ran 2:03.05 in 2016 before carbon Vapofly shoes

Also what were the comparison shoes worn?

Kipchoge “improved” by 2:21. His fastest marathon prior to the shoes was 2:04:00 in Berlin 2015. He won London 2016 in the first prototypes of the VaporFly (same ones Rupp wore at the trials that year).

One should also ask: is it possible that Kipchoge declined between 2015 and 2018, and the benefit is even larger than 2:21? Or the opposite, that he improved and it’s smaller? I’d hedge on the former given his age and general trends of marathon asymptotes in two-a-year elites, but if there was one to break norms, it’d likely be him.

https://www.alamy.com/stock-photo-eliud-kipchoge-elite-mens-winner-of-the-london-marathon-2016-running-114977438.html

Wasn't his 2:04 in exploded, worse than barefoot, shoes? Saying that 2:04 was his peak is a pretty extreme take.

Who in the top 10 in 2018 wasn't wearing the vaporfly? I remember you starting a thread back then asking this and having the answer be either all of them or 9/10, but maybe I'm misremembering. And the 2.1 might make sense for Kipchoge, but looking at top 100 times 2019 would need to be a really shallow year (the worst of the decade) for 2.1 to be reasonable. I'm not saying that that's out of the question, but a 1 minute average improvement with a handful of super responders feels more believable to me. With that adjustment 2019 becomes a very good year with lots of top end quality, but still wasn't as deep of a year as 2012, which had an absurdly quick 100th best time. 2018 also becomes average to a bit below average depending on adoption numbers rather than abysmal with the 2.1 adjustment.

I would think that women would see greater improvement as they are on the course a greater amount of time and taking more steps. Perhaps men have greater force at push off or the greater weight influence results?

ukathleticscoach wrote:

If it is between 2-4 mins how come Kipchoge only improved by 1:26. He ran 2:03.05 in 2016 before carbon Vapofly shoes

Also what were the comparison shoes worn?

No, he did not run 2:03:05 in non carbon shoes. Kipchoge was wearing vaporfly prototypes in all of 2016.

Here is the best pic of Kipchoge's 2016 London shoes. Notice how his shoes are different than the other Nike athletes. If that's not mechanical doping, I don't know how you'd define it.

reminder that Wired did a non-scientific sample of the sub-3:15 NYC Marathon results and found that Vaporfly wearers were far, far, far more likely to run the second half of the race close their first half.

Which suggests the benefit is from less pounding over the first half of a marathon.

And leaves open the question if the cheater shoes would help in a 5k or 10k, since the distance is so much less hard on the legs.

NB: it was 2017 so the sample size of cheater shoe wearers was small: 21

Wired:

Of the 92 photos (of the marathon), 138 runners have both shoes and bibs visible. Of those, 21 are wearing a version of the Nike Zoom Vaporfly—either the $250 4% or the $150 Zoom Fly—and 117 are not.1 We looked up the data for each of these 138 runners, and, interestingly, the Vaporfly runners finished much better. Of that group, seven, or 33 percent, ran negative splits. Of the others, 17, or only 15 percent, ran negative splits. The average Vaporfly runner ran the second half of the marathon a minute and forty seconds slower than the first. But the average non-Vaporfly runner ran the second half five and a half minutes slower. Both groups of runners had faded, but the people in the new shoes had faded less.

These results couldn't remotely be published in a scientific paper. The sample size is too small, and the standard deviations are much too high. There also could be alternate explanations. It's possible that runners who pay exorbitant prices for awkwardly shaped shoes are the kind of people who plan their races well. The shoes might, for some reason, work particularly well on wet roads or in humid weather or on a course with punishing descents down a series of bridges. There could be a placebo effect. Still, the numbers are suggestive: Nike may in fact have designed something that limits the agony of a marathon's final 10K. Certainly, the theory behind the shoes makes more sense for a race through the five boroughs than the last time there was a boom in marathon technology: when, about eight years, ago everyone started running barefoot to be more like the Tarahumara.

https://www.wired.com/story/do-nike-zoom-vaporfly-make-you-run-faster/

It looks like 22/36 podium finishers at the world major marathons in 2018 were wearing the vapor fly, with another handful wearing the Adidas equivalent, so I think it is fairly safe to say that the vapor fly was widely adopted by 2018.

@rojo: If you click on the picture I linked above, you can see the full side profile of the shoe with a bit of the tread pattern underneath, which is indicative of the original VF prototype (same ones that were used in the original 4% study).

Stanley Biwott was 46 seconds back in Zoom Streaks. He’s had two marathons where second place was less than a minute back in normal shoes, and in the Olympics Ghirmay Ghebreslassie was 2:20 back. GOAT*

This study is cool as, among other reasons, it adds some more evidence to interpret these retrospective analyses.

@lobster Yes, his Zoom Streak’s insoles were coming out at the end of his 2:04:00. It likely affected the performance a bit, but I’d say not by more than 15-20 seconds. It causes pain and blisters, but you’re still able to run fine. I’ve had this happen twice in workouts in different flats, and the first time I finished the workout with my feet ripped to shreds, but it didn’t seem to affect the actual paces (if anything, it’s a weird distraction). The second time I stopped because I didn’t want the repercussions of the blisters, ha. I don’t know his exact experience, but I suspect that 2:04:00 is a pretty good barometer of where he was pre-VaporFly.