IAAF INVESTIGATING VAPORFLY NEXT%

we can't allow the existence of a technology that is largely available to anyone

Literally anyone with a credit card can obtain VF Next%. And what will become of us the day that happens? We will have to hold multiple racing events to find out who's fastest.

No thank you!

Swimming's international body, FINA, did ban the 2008 and 2009 swim suits that provided extra buoyancy (like wetsuits), but it took them 2 years to do so, by which time most every world record was broken. However, FINA never invalidated any of those records, so some of them still stand today, seemingly unbreakable. IAAF should learn from FINA and not make the same mistake. Ban the shoes!

Yeah 1 carbon plate is ridiculous. 3 is just comical.

I think we will be entering an era in the running world where we cut open finishers shoes at the end to see what advantages they are trying to use just like corked bats in baseball.

I'm all for advances in cushioning but adding plates that act like springs is going too far. It's not even ethical really.

People laughed at the shoe company Spira for putting springs in their shoes. What's different about this?

Gullible much? wrote:

As for limiting shoes based on stack height, that's a workable standard, but why 31 mm? Because that would end up banning a lot of Hokas and maybe the Brooks Adrenaline. I remain in favor of letting gravity and weight increases determine the limit on stack height

As the BSJM blog post makes clear but doesn't say outright, Nike isn't doing anything hugely new here. They've just finally figured out how to combine the plate of track spikes (and Mizuno), the stack height of Hoka, and an even better foam than Adidas's Boost.

We said 31 mm just as a starting point for discussion, as that was what Nike originally reported the VF as, and what the early prototypes tested in the lab measured at. I’m not sure Nike underreported it on purpose, or if it was just not carefully done, but most outlets measure the retail version of the VF 4% at 36-37 mm (and the next% is thicker).

If that was set as the standard, it would actually include nearly all Hoka models. Even if you wiped the records in the VF and set it at a more “normal” 28-30 mm, that would include most of their racing shoes as well (I think their Carbon X is 32 mm - less than the retail VF). Moreover, it definitely wouldn’t prevent people from training in shoes with thicker midsoles. It would just standardize competition footwear - i.e. what people racing at the top level can wear if they want to set records, win prizes, etc.

Will someone turn this into a Pokémon meme? It’s evolving!

https://ibb.co/0DPTcWy

Whether you like the lady or not, check out the videos she made of Brigid's stride and foot strike. (This was posted as the quote of the day a few days ago. Not sure how many actually watched the videos in the link)

https://www.balancedrunner.com/chicago-marathon-2019-brigid-kosgei-running-form-analysis/

Watch her feet after they lift off. It's pretty clear the shoes are springing her by the way her feet react.

Entirely wrong. I hope the fellow engineers will chime in here and correct you.

An ideal spring returns to its original shape without dissipating any energy as heat. It returns 100% of its energy. It does not bounce up and down perpetually that makes no sense.

It does not store energy upon each compression and cumulatively build it up. That is the definition of an efficiency in excess of 100%. Which is impossible obviously.

And yes you want stiff spring material, a pliant spring is useless. A good spring is made of a material with a very high yield strength like steel. Carbon fibre reinforced plastic is extremely stiff, approaching that of steel and is about 20x stiffer than your wooden blocks.

Again, everyone who has reservations with this shoe appears to believe in shoes creating energy.

I want to hear from the person that accepts the shoes simply waste less of the runners energy from the runner than other shoes but still thinks they should be banned.

I feel that way. I think it’s great if shoes approach 100% efficiency, but the problem is that they’re now extending the biological leg with a non-fatiguable element that has no weight penalty (i.e. it weighs the same as previous flats, but is longer and functions as a near-perfect elastic element).

From the BJSM piece: “A midsole-thickness standard would regulate running shoes on their fundamental mechanical function—as springs. This is akin to simply regulating length of the spring and would encourage further technological advances by allowing manufacturers to develop lighter and more perfect springs (i.e. approach 100% efficiency in energy return while minimizing mass and optimizing architecture).” The goal should be developing great footwear that’s not an “unrecognizable extension of the body”.

Put a geometric limit on what defines a shoe on an athlete and allow innovation within that space.

My gripe is against the people arguing that it should be banned because of their use in Recovery. People do hard runs in them and don’t feel so beat up the next day, then opponents come on and say this is bad.

Why is that bad!? That sounds like a really good thing and I hope the technology gets more widespread, especially for those of us who live in concrete paradises with no real access to dirt or grass for much of the year.

To all the non-Nike athletes complaining about the Vaporfly -

Your job as a sponsor is to endorse their product, meaning that you act as an advocate for them and their products as you are providing . Complaining about how a competing company's shoe provides an unfair advantage is conceding that your sponsor's products are inferior. "Unfair technological advantage" reads "my sponsor's products aren't as good and are obsolete."

exrunner wrote:

No shoes can return more energy than put into them.

exrunner wrote:

Again, everyone who has reservations with this shoe appears to believe in shoes creating energy.

You could not be more wrong. You keep beating up that straw man though. Your arguments are completely irrelevant. The few people claiming the shoes create energy are either trolls or just not being careful enough with their wording. There are many people who oppose these shoes who understand that they don't create energy. But you are completely missing the point. Just because they don't create energy doesn't mean they are okay. Rollerblades don't create energy either, but they aren't okay.

Hypothetically, if Nike's shoes RETURN (not create) 75% of the energy while all other shoes RETURN (not create) 25% of the energy, then Nike's shoes have a very clear advantage. They do not have to create energy to have an advantage. If they simply return significantly more energy than other shoes, then that is a significant advantage. You seem to be struggling to understand this very simple point. Whether the shoes create energy or simply return more energy is completely irrelevant to most of the arguments people are making.

Actually the opposite?

In 2007 IAAF banned the blades. IAAF and Oscar agree to run test in 2008 which the study concluded an unfair advantage is gained. Oscar appealed to the CAS which overturned the decision based on part on additional MIT studies and in part to disputing claims of 1st study.

https://www.google.com/amp/s/www.iaaf.org/news/amp/news/pistorius-is-eligible-for-iaaf-competition

For those that think this is entirely an energy efficiency issue, read this article which includes others that drew different conclusions from that same MIT study with respect to the mechanical advantages vs efficiency and the role each play.

https://www.google.com/amp/s/www.technologyreview.com/s/414233/blade-runner-has-no-clear-edge/amp/

Right now my view is as long as the shoes are reasonably available to everyone they're legal. The shoes are 350 bucks not 30,000 like the swimsuits. Dont forget both of which I believe have a very short lifespan making 30Gs much more out of reach of poorer countries.

exrunner wrote:

Springheel Jack wrote:

You've never been on a trampoline, have you?

Oh God.

Trampolines don’t create energy.

Is everyone’s issue with these shoes based around the fact that they are thick as f*ck?

Fins on a swimmer do not create energy either, they improve the efficiency of flutter kick to propel the swimmer forward with more force. The natural build of a human is not optimally efficient for the act of running, so if we modify the way humans run, they do so faster with more efficiency. Perhaps if humans were designed more like ostriches, they could run as fast as them.... perhaps we could add some technologies to the human to make the run more like ostriches...

Why do Ostriches run so much faster than humans?

"Ostriches can run so fast because of the elasticity in their joints, scientists have found. Ostriches, which are the fastest bird on the land, use tendons to store and return twice as much elastic energy per step than humans."

Height isn't a bad starting point at all, but would you keep that at 31mm across all shoe sizes? If so, then you've created a new problem. The industry already changes the height of the midsole, increasing in height as the size of the shoe gets larger to compensate for athlete weight among other things. The height of the foam determines how much energy can be stored and then returned, so if you limit it to 31mm, suddenly you're allowing the smaller sizes an advantage over the larger ones.

Regulation is probably a great idea, but finding the perfect solution is going to be extremely tricky.

If it were as simple as several plates why can’t the other companies provide an alternative?

The air pocket was copied why not the plates?

What are you even talking about?

A perfect spring would continue to bounce perpetually as it would not dissipate any energy.

1.An object in motion will stay in motion, and

2.every action has an equal or opposite reaction.

You drop a perfect spring on the ground and it would perpetually bounce up and down as it would return 100% of the force applied to it on each bounce. (Ignoring drag)

You seem to be describing some kind of perfect damper, which is the exact opposite of a spring.

The Next% is the wrong show to investigate.. what a waste of time.

runNomad.com wrote:

The Next% is the wrong show to investigate.. what a waste of time.

Lighten up, Colby.