For the past 50 years, running shoes have only made small changes and updates in terms of functionality and improving performance. Some advancements in shoe technology have made a small ripple in the running world, but nothing like the tsunami the Nike Vaporfly created. If you look at pictures from major marathons and look at the elite field, you will now be looking at 95% of the top runners wearing a version of the Nike Vaporfly. Nike claims it reduces the energetic cost of running, which will make you run faster. This of course is a huge claim, and will leave many people skeptical. Does this shoe deserve all the hype it’s getting? If so, how much will it help improve your race times?
Since the introduction of the controversial shoe designed by Nike, the Vaporfly 4% has been lab tested and proven to make runners more economical by 4% on average, according to the original study out of CU Boulder in 2017. Then in 2019 the improved version, the Vaporfly Next% was shown to improve your running economy by closer to 5% on average. This does not mean you will run a 4-5% faster time, but instead means your body will be using 4-5% less oxygen to run at a given speed, making you more economical. If you think of it in terms of cars, running economy is basically looking at how fuel-efficient a car is. Would you rather drive a car that can get 30 miles per gallon at 60mph, or drive one that can go 4% faster, but still burning the same amount of fuel? Originally, many scientists and runners believed this to be more of a placebo effect, accrediting the performance benefits from people wearing them to be more of a psychological advantage. Anytime new technology or new supplements hit the market that claim to make you 4% faster or stronger, other studies come along and disprove their claims, but this isn’t the case with the Vaporflys. Since the original study in 2017 showing the 4% improvement in running economy from the shoe, several other lab tests were done by other companies and researchers that came to the same conclusion; the Nike Vaporfly will allow you to run faster using less effort! This in itself is enough evidence to show the legitimacy of the shoe, but to go along with the dozens of lab tests, marathon times since the birth of the shoe have improved at a dramatic rate.
In 1968 the world record for the men’s marathon stood at 2:09:36 by Derek Clayton, and over the next 20 years it slowly improved until in 1988 it dropped to 2:06:50 by Ethiopia’s Belayneh Dinsamo. Another 20 years from that at the 2008 Berlin Marathon, the great Haile Gebrselassie set the mark at 2:03:59. As we can see, it isn’t uncommon for the world record to fall by about 3 minutes every 20 years. What is uncommon is for it to drop nearly 2.5 minutes in just half the time, and that’s exactly what happened when Kipchoge set the current record in 2018 of 2:01:39 wearing the Nike Vaporfly NEXT%. Kipchoge isn’t the only one to improve from using the shoe. In 2014 Dennis Kimetto set the world record of 2:02:57 before the vaporfly was created. Now his world record from just five years ago isn’t even among the top five in history, because those top 5 times now belong to runners wearing versions of the Vaporfly, and this doesn’t even count the 1:59:40 marathon Eluid Kipchoge ran in October of 2019. Although his sub 2 hour marathon doesn’t count as an official world record, it still would not have been possible without the improved version of the Vaporfly, the Alpha Fly, that he wore in that controlled time trial setting. Lastly, along with the men’s recent accomplishments in the Vaporfly, the women’s marathon world record was destroyed by Brigid Kosgei in the Chicago Marathon this year when she ran 2:14:04 in a pair of the Nike Vaporfly NEXT%, beating Paula Radcliffe’s WR by 81 seconds. Radcliffe’s world record was already such an outlier because only 1 other woman has run within 2.5 minutes of Paula’s world record from 2003, then Kosgei beats that by nearly 1.5 minutes. This shows us that people are clearly getting an advantage from wearing the shoe, but how much of an advantage is the real question.
When the shoe first came out, many thought the 4% was how much faster it would make you, but as I just mentioned, it actually increases your running economy by 4% on average. A 4% improvement in oxygen-saving abilities translates to roughly about a 2.6% improvement in time for a 2:03 marathoner. To be safe, let's assume Kipchoge only received half of the performance claim by having a 1.3% improvement in his marathon time from the shoes. You may be thinking 1.3% doesn’t sound like much, but for someone running a 2:02:57 marathon (what the world record was before the introduction of the vaporfly) that improves their performance by roughly a minute and a half, which is right where Kipchoge’s current marathon world record is from Berlin in 2018. So if the shoe is taking off a minute and a half from the top marathoners in the world, we're basically seeing the same 2:03 guys from 2014 running 2:01 strictly because of the improvements in shoe technology. As Sports Scientist and Professor Ross Tucker explained, “We bypassed physiology by improving the economy through the use of the shoe.” The shoe basically caused us to make a quantum leap 20 years into the future for marathoning.
A 4% improvement in running economy may not sound like much, but if you’re a 3:00 hour marathoner in a normal pair of racing flats who is now running in a pair of the vaporflys and you’re using 4% less oxygen, your time would improve to a 2:55:19 just from the shoes! Personally, I think a 2:55 sounds much better than a 3 hour marathon! So if you’re really close to a Boston Qualifying time or a new Personal Best, that 4% can mean a lot! Here is a table I created showing how much certain marathon times would improve if the runner were to switch to wearing a Vaporfly. Remember, this is based off of a 4% improvement in running economy, which translates to about a 2.6% improvement in time for a marathon! Members can follow each other, write and reply to comments and receive blog notifications. Each member gets their own personal profile page that they can customize.
Racing flats have always been a necessity, especially for elite marathoners. Shoe companies would often struggle trying to find the perfect mixture of cushion and weight, because adding extra foam would increase the weight of the shoe, which would obviously be counterproductive for fast marathon times. So it’s proven that the shoes work, but what is so different about them?
Well, there are 3 main things:
The foam inside the shoe
The carbon fiber plate
The stack height
The foam Nike uses in all the vaporfly models is called “ZOOM X Foam” and an aerospace company created it. Most foams in shoes return about 65% - 75% of your energy with each step, but ZOOM X foam is the most responsive foam on the planet, returning 88% of your energy. Along with that, the foam is lighter weight than traditional shoe foams, which means you can package more of it into a large volume without adding additional mass to the shoe. All this extra foam is what increases the stack height of the shoe which allowed Nike to put a curved carbon fiber plate in the middle of the Zoom X foam. So as your foot hits the ground, energy travels through the foam, then is stored in the carbon fiber plate that acts as a spring like mechanism so the energy can then be returned to help you with your forward propulsion. This new form of mechanical doping has changed the way we have to view the recent successes in the marathon.
Many believe the shoe should be banned, especially from elite runners. If you’re not a Nike sponsored athlete and you’re forced to run in a shoe that doesn’t give you this economic boost, it is a clear disadvantage just from wearing a specific shoe. The good thing is other shoe companies such as Brooks, Saucony, and Asics are going to be releasing their version of the Vaporfly in 2020. This will make the elite field much more fair, but at some point shoes are going to have to be regulated because before long they may have rockets attached to the end of them!
It’s clear we’re in a new age of shoe technology because of the mechanical advantage runners are getting from these super shoes. Be prepared, because since the acceleration rate of marathon times since the introduction of the Vaporfly, I believe qualifying times to major marathons, like Boston and New York will make another couple minute jump, making them harder to achieve. So if you’re worried about placing in your age group or hitting those qualification times, it's best to adapt to the changes and go get a pair of the Vaporflys. If you still don’t think they make much of a difference, be prepared to basically give everyone else a 3-5 minute head start at your next marathon.