ElonMusk wrote:
CONCLUSION
Npositive=RWspend$ * WIREDfreeshoes*NtripstoMonza
The best thing about PR is that there's no shortage of freebies you can give to "journalists" to write positive stuff. How do you think Runner's World has survived all these years?
fisky wrote:
Even a slight deviation could negate the benefits. Energy released before the foot reaches push off position is lost. Energy released after the shoe leaves the ground is lost. Energy released at the wrong point on the shoe is reduced.
All the acceleration in running comes from the body pushing against the plant foot. If a spring or whatever energy restorer pushes the plant foot upward or forward, the muscles pushing the body away from the plant foot must exert extra force to compensate, otherwise the foot would simply move closer to the body. It is not a free bounce.
The forward or upward motion in the toe of any shoe - the last point of contact - is insignificant in any case, and I don't believe any shoe could time its springiness precisely enough to make any difference. Bounciness in the heel could possibly relieve fatigue in some muscles, but I doubt any shoe does that. A certain well-tuned track might, on which MD runners with a particular form are able to set records. But this relies on adapting to a prolonged footstrike and lower cadence, and I think it's useless over long distance and harmful to sprinters.
The world record for a mile on a pogo stick is over 10 minutes. Running isn't about bouncing.
9 seconds per mile faster with low profile springs in the soles of running shoes:
Claims of a 9 second per mile improvement can be dismissed out of hand. Kiprop's not running 3:17.
It's been a while since university physics, but isn't energy return from shoe a zero sum equation? These shoes do not create energy, but just minimize losses. I'd be shocked if the incremental gains from these shoes are anywhere near the improvements yielded from moving from cinder to state of the art synthetic track surfaces.
As long as the shoes are not creating energy, all forward propulsion is created by the athletes muscles. Improvements to shoes and running surfaces are just improving efficiency. You can't exceed 100% efficiency, but anything that gets us closer should be allowed.
I'm personally excited about aerodynamic headwear!
zzzz wrote:
yourmom.com wrote:I was thinking about that in a similar way and completely agree.
Maybe there is some angle or shape that returns some level of energy using a certain type of gait that is optimized for someone for like kipchoge.
There's no way it works as well for a 7min/mile pace joe jogger or even other elites who have a different gait.
I really want to see specifically what this "spoon" shape is in the new shoe and how it's angled and where it is placed.
I'm also kind of surprised that something like this doesn't have some effect on the runner's mechanics - especially a fine-tuned elite logging +100miles/wk - IF it actually does have some kind of remarkable energy return. The Wired article author says he can hardly stand in these shoes... you'd think a drastic shoe change would be a gamble that might have all kinds of slight side effects on kipchoge's mechanics that can add up to seconds here or there in a marathon, in a bad way.
I think there is a lot less tuning than Nike or you guys suggest. I disagree with fisky's comments on the timing of energy release being something that needs to be tuned. On the contrary, springs are excellent at releasing energy at exactly the right time in this series (as opposed to parallel) kind of system. It would be hard to design it so that the timing is off. You see this in things like pogo sticks, flex in bicycle frames (that is NOT all wasted contrary to advertising, just the little portion that is lost due to the bike frame material not being 100% elastic), and trampolines.
A spring in a shoe would be loaded at the same time the runner's leg is being loaded up in its own spring-like manner (plus additional force added), with the part that is under the ball of the foot what you should be paying attention to because that's where the push off force is coming from (both body and energy return from shoe). The maximum force applied by the body to the legs occurs the same time as the maximum force applied by the feet to the shoes (thus close to the maximum force applied to a spring in a shoe): When the body's center of mass is directly over the ball of the foot (see any of the force plate graphs with any style of running - forefoot and heel strike, doesn't matter). The force applied to the ground decreases immediately afterward that point. The energy return force on a spring in a shoe is automatically released from the shoe starting because the force on the shoe decreases.
You can step on a leaf spring in a non-optimal place (not at the highest camber) for energy return or trampoline in the wrong place (not in the center) and not get as much bounce out of it. I don't think this would be too much of an issue in a shoe because different shoe sizes match up foot size with plate size/camber position, but sure, there is probably some individualized tuning that would help match that up better because no everyone's foot is the same. It's possible that the shoe works best with a certain type of running style too.
All this is not to say that I buy the advantage that Nike claims. And, like I said in a previous thread, the ideas that this Nike shoe uses - springy foam and stiff plate have long been used in some running shoes and spikes, so I don't think the combination should be banned.
I agree with mostly everything but slightly differ on your part about the trampoline.. what happens if the foot is oriented in an inverted or everted position and energy is returned? It will propel the leg into an unnatural kinematic pattern, and then eccentric muscle work is needed to slow the leg down or correct the pattern. If TOO much energy is returned, then eccentric muscle work is needed to slow the limb, despite moving in the correct direction. Both of these situations would negatively impact running economy.
ClonedDuck wrote:
zzzz wrote:I think there is a lot less tuning than Nike or you guys suggest. I disagree with fisky's comments on the timing of energy release being something that needs to be tuned. On the contrary, springs are excellent at releasing energy at exactly the right time in this series (as opposed to parallel) kind of system. It would be hard to design it so that the timing is off. You see this in things like pogo sticks, flex in bicycle frames (that is NOT all wasted contrary to advertising, just the little portion that is lost due to the bike frame material not being 100% elastic), and trampolines.
A spring in a shoe would be loaded at the same time the runner's leg is being loaded up in its own spring-like manner (plus additional force added), with the part that is under the ball of the foot what you should be paying attention to because that's where the push off force is coming from (both body and energy return from shoe). The maximum force applied by the body to the legs occurs the same time as the maximum force applied by the feet to the shoes (thus close to the maximum force applied to a spring in a shoe): When the body's center of mass is directly over the ball of the foot (see any of the force plate graphs with any style of running - forefoot and heel strike, doesn't matter). The force applied to the ground decreases immediately afterward that point. The energy return force on a spring in a shoe is automatically released from the shoe starting because the force on the shoe decreases.
You can step on a leaf spring in a non-optimal place (not at the highest camber) for energy return or trampoline in the wrong place (not in the center) and not get as much bounce out of it. I don't think this would be too much of an issue in a shoe because different shoe sizes match up foot size with plate size/camber position, but sure, there is probably some individualized tuning that would help match that up better because no everyone's foot is the same. It's possible that the shoe works best with a certain type of running style too.
All this is not to say that I buy the advantage that Nike claims. And, like I said in a previous thread, the ideas that this Nike shoe uses - springy foam and stiff plate have long been used in some running shoes and spikes, so I don't think the combination should be banned.
I agree with mostly everything but slightly differ on your part about the trampoline.. what happens if the foot is oriented in an inverted or everted position and energy is returned? It will propel the leg into an unnatural kinematic pattern, and then eccentric muscle work is needed to slow the leg down or correct the pattern. If TOO much energy is returned, then eccentric muscle work is needed to slow the limb, despite moving in the correct direction. Both of these situations would negatively impact running economy.
Here is the science that proves LEAF springs improve running economy
http://iom3.tandfonline.com/doi/abs/10.1080/19424280.2015.1018342?src=recsys&journalCode=tfws20and
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0172287I'm running barefooted from now on.
Here is the science that proves LEAF springs improve running economy
http://iom3.tandfonline.com/doi/abs/10.1080/19424280.2015.1018342?src=recsys&journalCode=tfws20and
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0172287
You need to be more critical of what you are reading. Both studies are for HEEL STRIKERS. No claim about how the leaf spring affects midfoot or forefoot strikers. Could be different to loading parameters, contact times, etc.
Both studies have a slow running speed (3.0 m/s) which is close to 9 min/mile. What happens at 4:40 / mile? Again, changes in loading parameters may affect this.
both studies support that if you're jogging around and heel strike, leaf springs will probably be of benefit. Beyond that, there is no evidence to say they will benefit. Not saying an extrapolation probably wouldn't hold true, but critical analysis is needed in the claims of where performance will be enhanced.
ClonedDuck wrote:
Here is the science that proves LEAF springs improve running economy
http://iom3.tandfonline.com/doi/abs/10.1080/19424280.2015.1018342?src=recsys&journalCode=tfws20and
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0172287You need to be more critical of what you are reading. Both studies are for HEEL STRIKERS. No claim about how the leaf spring affects midfoot or forefoot strikers. Could be different to loading parameters, contact times, etc.
Both studies have a slow running speed (3.0 m/s) which is close to 9 min/mile. What happens at 4:40 / mile? Again, changes in loading parameters may affect this.
both studies support that if you're jogging around and heel strike, leaf springs will probably be of benefit. Beyond that, there is no evidence to say they will benefit. Not saying an extrapolation probably wouldn't hold true, but critical analysis is needed in the claims of where performance will be enhanced.
Also like the guy above said in reference to physics, neither of these studies conclude that the shoes create energy or return more energy than they receive. The find that the LEAF shoes improve efficiency. The first found oxygen costs and stride rates decreased in the leaf shoes. The second found muscle forces decreased in the leaf shoes.
External validity aside and whether or not these results apply to all runners and foot strikes, there's not thing here to suggest the benefits of these are any different than the benefits of other shoe or running surface improvements.
I totally understand the above questions over whether it is relevant to use a study about heel strikers. However the bottom line is that mechanical cushioning device that have a directionality to the energy return can impact running economy. I'm not stupid. I know that you can't get more energy out of a system than is put in and i never claimed that. What i claim is that certain methods of mechanical cushioning can impact things like stride length, and rate and thus can artificially enhance running economy.
heyyo wrote:
ClonedDuck wrote:You need to be more critical of what you are reading. Both studies are for HEEL STRIKERS. No claim about how the leaf spring affects midfoot or forefoot strikers. Could be different to loading parameters, contact times, etc.
Both studies have a slow running speed (3.0 m/s) which is close to 9 min/mile. What happens at 4:40 / mile? Again, changes in loading parameters may affect this.
both studies support that if you're jogging around and heel strike, leaf springs will probably be of benefit. Beyond that, there is no evidence to say they will benefit. Not saying an extrapolation probably wouldn't hold true, but critical analysis is needed in the claims of where performance will be enhanced.
Also like the guy above said in reference to physics, neither of these studies conclude that the shoes create energy or return more energy than they receive. The find that the LEAF shoes improve efficiency. The first found oxygen costs and stride rates decreased in the leaf shoes. The second found muscle forces decreased in the leaf shoes.
External validity aside and whether or not these results apply to all runners and foot strikes, there's not thing here to suggest the benefits of these are any different than the benefits of other shoe or running surface improvements.
heyyo wrote:
the B standard wrote:If any of you had taken the time, and some surely have, to read Nike's patents that were linked on this site a week or two ago you'd know that these are 100% designed to be against the spirt of the sport.
It's like a little carbon fiber leaf spring. Not massive, but definitely something that could greatly help people who have bad control of their feet or weak arches and plantar fascia and a little help with people who have great control of their feet.
Wait until the real cyborg stuff comes along. This is hardly scratching the surface.
can you explain why carbon fiber leaf spring is against the spirit of the sport but the transition from leather soles to nike air wasnt/isnt? or why spikes aren't against the spirit of the sport?
The leaf spring artificially increases the stiffness of the foot's arch while Nike Air decreases it. We see this in cycling shoes as well. Extremely stiff soled shoes allow riders with weaker feet to lessen the advantage of those who have better feet. It is not nearly as much of a factor in cycling due to the fact there is very little eccentric component involved, whereas the eccentric component of running and how the body absorbs and returns that energy makes a massive difference. Paralympic athletes must have their prosthetics approved due to the fact we can engineer parts that are better at transferring power than what we are naturally born with.
Spikes allow better traction, which purists could rightly argue is incorrect to allow, but in general it's something that has been accepted by the sport. If people accept that leaf springs are ok to use that's fine, but not if only one company can make them. If Nike was the only shoe company that could make spikes they would not be allowed in Track and Field, although I wouldn't put it past USATF to try to allow it since they're owned by Nike.
This is the key point, and this is why this shoe will work for Pro's because they will tune the stiffness for each athlete ensuring that the MTP still flexes. All the studies show that stiffer forefoots have responders and non-responders. If you respond (MTP flexion) then you get a benefit, if you don't respond then it makes you slower.
Bottom line - the facts clearly state that the plate is changing biomechanics, whereas NIKE are now claiming that it is all the foam. 2 caveats to that: Original NIKE PR releases talked about propulsion from the plate until they got negative publicity. Rumour has it the magic NIKE foam is available in-store soon on Reebok's Floatride shoe!
The other major point is that if you buy the cheaper joe public version of the Breaking 2 shoe with the NON-CUSTOMIZED Nylon plate, you will not know if it works for you or not. Essentially an expensive gamble to find out if it makes you 4% faster or slower!
Not stupid wrote:
https://www.bartoldgold.com/blog/latest-news/stiffer-shoes-improve-running-energetics-as-long-as-first-mtp-flexion-is-preservedThis is the key point, and this is why this shoe will work for Pro's because they will tune the stiffness for each athlete ensuring that the MTP still flexes. All the studies show that stiffer forefoots have responders and non-responders. If you respond (MTP flexion) then you get a benefit, if you don't respond then it makes you slower.
Bottom line - the facts clearly state that the plate is changing biomechanics, whereas NIKE are now claiming that it is all the foam. 2 caveats to that: Original NIKE PR releases talked about propulsion from the plate until they got negative publicity. Rumour has it the magic NIKE foam is available in-store soon on Reebok's Floatride shoe!
The other major point is that if you buy the cheaper joe public version of the Breaking 2 shoe with the NON-CUSTOMIZED Nylon plate, you will not know if it works for you or not. Essentially an expensive gamble to find out if it makes you 4% faster or slower!
When I was living in the UK in 2003/2004 the big buzz was over the Nike Mayfly, my thoughts originally were that a slight variation on the Mayfly's that were more robust would be adopted by the major shoe makers. But this seems like opposite direction.
In my opinion, any shoe that acts as a spring on your foot needs to be banned. The winners should not be different in terms of footwear, but rather in terms of running ability.
Foot strength and biomechanics should be a part of training that is just as important as mileage, lifting, nutrition, sleep, etc. We should not be able to rely on springy shoes to make up for our disadvantages.
Lots mentioning instability with this shoe, nobody noticed the crazy amount of torque it's applying to the runner. The stack height on this is FAR too high for this carbon effect.
Tune Boost at the current height in Adola's shoes, with a 'spoon' such as this, or just go with what Mizuno has, and both those shoes would kill whatever Nike comes up with. Not that Adidas needs anything more to still have the world records, that is.
Brett Schoolboy wrote:
The funny thing is that the athlete tuning for the elite version is exactly why nobody should buy the non-customized joe public shoe. For some it may improve, and for some it may hinder performance.
Okay, so exactly what is the difference between the elite/non elite version, other than the place being customized?
Can joe public buy the elite version? And if so, if he is in the same ballpark as an elite runner in terms of height and weight, would it be more likely that the elite version would help them? Or is it based on running biomechanics as well?
just a question wrote:
other than the place
*plate
Runsmith wrote:
In my opinion, any shoe that acts as a spring on your foot needs to be banned. The winners should not be different in terms of footwear, but rather in terms of running ability...
Imagine if golfers/tennis players/pole vaulters were still using wooden equipment. Nike innovates, always. Others are now behind.
Dupafly. wrote:
Runsmith wrote:
In my opinion, any shoe that acts as a spring on your foot needs to be banned. The winners should not be different in terms of footwear, but rather in terms of running ability...
Imagine if golfers/tennis players/pole vaulters were still using wooden equipment. Nike innovates, always. Others are now behind.
Confused why clearly breaking IAAF rules is considered “innovating” when it comes to Nike.
But this is the IAAF’s fault. They aren’t following through on their own rules and letting Nike athletes use the shoes.
Happy for Shalane, Amy, and Rupp but you’re crazy if you think the shoes haven’t played a role.
Jordan too. She can’t compete at the elite level- minus making worlds in 15- and she gets the shoes, hits the roads and is US #2 all time? I love her, but come on.