Vaporfly 4% Improvement

Do we really have to go this discussion again? The argument is simple, any shoe with a device inside of it shaped with the intension of springing the runner forward should be banned. The reebok run fast pro uses the exact same foam and we are not calling for that to be banned. Take the spring like carbon fiber out of the 4% and we have no problem with it.

Either you believe in science or you don't. The spring plate definitely makes you run faster, but it's the same concept as a rigid spike plate. Should spikes or shoes of a certain stiffness be banned? I fully believe that the benefit of the Vaporfly is the combination of the built-in spike plate for rigidity and the springiness of the foam. If the spring plate was just called a plate, I bet a lot of people wouldn't have an issue with these shoes. The plate is not a spring, no matter how much you turn your face away from the science and insist otherwise. This is the whole debate in society as a whole now though, isn't it? There are no authorities any longer, just different sides screaming that they're right without any foundation to stand on.

Alex Hutchinson is not a scientist or study researcher, he is an opinion author, like a well-educated commentator you'd see on TV for a political issue, just happens to be for sports science.

Anyone who has run even once in a vaporfly or (2018) zoomfly or any newer nike with a carbon spring will instantly know there is something "not kosher" and foreign, it's not just bouncy, it has forward propulsion from the shape of the spring. It's not a flat-plate, it's shaped exactly like a mini-version of Oscar Pistorius's "blade runner" spring:

https://i.imgur.com/iNhdeaT.gif

All they have to do is remove the carbon spring and we'll all shut up about it, well most of us.

Tomorrow I have a 10 mile race on Long Island. It's my first time racing with the shoe. The one training run I had felt awkward for the first few minutes and then very smooth. My overall pace was significantly faster with similar effort.

Last year I ran 66 mins and hope to go sub 65. Plan on starting at about 6:40 and going negative. I'll post tomorrow with hopefully good news.

Yeah, sure - by THAT logic please run a marathon in spikes and get back to us. Thanks.

Where did I write that Alex Hutchinson is a sport scientist? Did you even read the article? He's a journalist that reports on sports science and that science is discussed and referenced in the article. Just because a shoe "feels" likes it's springing you forward (because of it's shape, stiffness, and springy foam) doesn't mean it has springs in it. No matter how much you wish something to be true doesn't mean it actually is.

[quote]Alex Hutchinson Article in Outdoor Magazine wrote:

"The results were somewhat unexpected. The bending of the carbon fiber plate stored and returned energy at a rate of 0.007 watts per kilogram with each stride. In comparison, the squashing and unsquashing of the thick ZoomX foam returned 0.318 W/kg/quote]

You've happily quoted this so please explain EXACTLY how they came up with these numbers. Thanks.

Here's the link to the research (you'll need to create an account to see the full study). Do I know "EXACTLY" how the rotational axis material testing machine used by the researchers at CU works? Sorry, no I don't. Do I think they know what they're talking about more than people with strong opinions and feelings about the matter on this board? Yes, I do.

https://link.springer.com/article/10.1007%2Fs40279-018-1024-z

"Alex Hutchinson is not a scientist ..."

actually Alex has a Ph.D. in physics from Cambridge.

you know, that university where Newton and Steven Hawking were professors.

(yeah, Alex wasn't a student when Newton was a professor, but you get the idea).

So after the 150 mile "lifespan", do the 4% become 0%? 2%? -4%

I don't get all the vitriol over the Vaporfly 4% by some posters on LetsRun. Here is technology that makes our sport better and these posters consider it tantamount to cheating.

By that logic, GU should be banned, as it is a proven performance-enhancing substance.

My only problem with the 4% is that it's way too expensive. Drop the price to $120 and every runner on this board would own a pair.

Oh, and make a spike 4%.

Indubitably. $250 is a ridiculous price point and—while I could afford it—I refuse to pay that much out of principle.

^^^ You're not the only one. Count me out as well.

Alex Hutchinson Article in Outdoor Magazine wrote:

"Do I know "EXACTLY" how the rotational axis material testing machine used by the researchers at CU works? Sorry, no I don't. Do I think they know what they're talking about ... Yes, I do."

Ha ha, I love that!

Seriously though, I read that paper weeks ago when it was first released (in fact it was perhaps here that someone posted a link to the full paper) and there was absolutely nothing to qualify where these figures came from. i.e. was shocked to find they had not even removed a plate and tested it in isolation.

Now whilst it's absolutely fabulous that you are prepared to believe something completely blindly because someone has written it in a paper, the crux of the matter is that if you are going to claim that it's the foam not the spring you must explain how these numbers were calculated because otherwise citing that paper is worthless.

if the CU study had removed the plate and tested it in isolation you still would have complained and said, "the plate acts differently when it is embedded in foam". It made sense for them to test the total bending stiffness in intact shoes.

If it’s just the foam accounting for most of the 4% improvement, then shouldn’t the Pegasus Turbos give close to the same improvement? If it’s mostly the carbon fiber plate then you should see the same kind of improvement from the Zoom Flys right? Has anyone compared these shoes to see what kind of improvement they give?

To me how much the plate works compared to the foam is not the big concern with these shoes. It is the intension of the plate to be a spring that sets a horrible precedent. It is like someone coming up with an legal PED and people saying we shouldn't care because it doesn't work as well as you think. Where is the line then? If someone sets records in the bionic boots are we supposed to be ok with it? From what I've seen those of us that are against the 4% are consistent in our argument while those for the shoes have never defined a line for when a shoe should be banned.

ChonskyBoy wrote:

Indubitably. $250 is a ridiculous price point and—while I could afford it—I refuse to pay that much out of principle.

Well in Europe they cost 250 € : $284 !

We’ve had full length carbon fiber spike plates in sprint spikes for decades, and they’ve been shown to improve performance by 2-3% on average:

https://www.ncbi.nlm.nih.gov/m/pubmed/15079988/

All of the current men’s sprint records were aided by springy spike plates. Why should the marathon be any different? If the IAAF cared about this type of aid they would have banned them a long time ago.