Fast Shoes
In the past few months nike’s Vaporfly (also called Next%) running shoes have been the subject of so much attention, with world records, national records and personal records being destroyed left and right. Many non-elite and recreational runners are also enjoying the benefits of these shoes, whether it be to finally nail a long awaited PR or even that BQ or OTQ.
The Hype is Real
Maybe you’re wondering if all the chatter is just clever marketing by nike, or if these special shoes really do provide benefit for some people.
At this point there is a lot of data and research on the vaporfly and there is absolutely no question that these shoes make you run faster. Significantly faster. Up to several minutes in a marathon. Now, don’t worry if you’re not a nike fan (like myself) — other running brands have been developing their own models that work in the same way. All of these will be on the market to buy this spring, but save your pennies and expect to pay upwards of $200-$300. I am personally waiting for the Saucony Endorphin Pro to become available!
UPDATE: 5/5/20 I just pre-ordered my Saucony Endorphin Pros! Read my review here.
A Carbon Plate, Lots of Foam, and a Thick Stack.
Top: Nike Alphafly, Saucony Endorphin Pro
Bottom: NB FuelCell TC, Brooks Hyperion Elite
How They Work
The vaporfly shoes have 3 distinct advantages or improvements over your typical running shoes: The carbon fiber plate, the cushioning foam, and the stack height.
Vaporfly (Next %)
Cushioning
Nike is using a new midsole foam material that is very squishy, very springy, and very lightweight (low density). Because it’s so light, the shoe can have a ton of cushioning without becoming super heavy.
This new material has greater energy return than any material ever used before. It squishes a lot and then springs back really well. The foam is the propulsion in this shoe.
Carbon Plate:
The carbon fiber plate is very stiff and runs the length of the shoe sole. This plate prevents you from flexing at the big toe, which is a great energy saving because normally your body is doing work when you flex at the big toe. This shoe does that for you. The plate also offers structure in the thick layer of cushioning.
Leg Length
Nike’s vaporfly shoe has a thick stack height or platform that adds 2-3cm to a runner’s “effective leg length” (the distance from a runner’s center of mass to the ground) but because of how lightweight the foam material is, the shoe isn’t heavier than a thinner more typical model.
In the animal kingdom, the cost of transport (the energy required to move) goes down as effective leg length increases. In other words, if you have two creatures with the same body weight and one has longer legs, the one with longer legs is more efficient. So in the vaporfly, you have additional leg length without significant extra weight, which improves your running economy. Simply put you can run further before you fatigue.
The “Cheaterfly”
Because these new shoes provide a distinct advantage to anyone wearing them, the terms “mechanical doping” and “cheaterfly” have been coming up in the discussion. Is it fair for some runners to be wearing these shoes if they provide an advantage?
There’s a huge range in opinions in this “grey area” and since this is my website and my article here’s what I think:
Want to hear from experts on this topic? The information in this article has been summarized from The Science of Sport Podcast: The Shoe That Broke Running
Give it a listen to hear sports scientist Ross Tucker and biomechanist Geoff Burns discuss the vaporfly.
Since these shoes came out, world records and national records have been obliterated. Records are made to be broken, but the shoes are providing an advantage that past runners did not have when setting the old records. I believe all records set by a runner wearing these shoes should have an * and even better, I wish a new set of records could be established instead of erasing the records set without a mechanical advantage from shoes.
At this point it is public knowledge that the vaporfly provides an advantage, so each person can make a decision whether or not to purchase and wear that advantage. But only recently has this advantage become common knowledge. Four years ago, nike athletes were already wearing special prototypes (disguised to look like a standard model shoe) at the Olympic Trials and at the Olympics. They wore these shoes knowing they had a secret advantage, which is probably where the term “cheaterfly” came from.
Don’t Drop Your Old Model
When I have a runner preparing for a marathon, I make sure to discuss the extra advantage available from these specific shoes. It’s my responsibility to let them know the shoes actually work.
But these fast shoes change the way your body works while running (stiff carbon plate prevents flexing big toe) and should not be used exclusively. If you want to invest in a pair of fast shoes, they should be in addition to your regular runners.
I recommend limited use of carbon plated shoes that changes the mechanics of your body. Save them for race day and some key workouts and long runs.
Credit Where Credit is Due
If you do choose to race in the vaporflys and run a fast time or a new PR, please add an * beside that time. Understand that there’s no way of knowing how much of your new record had to do with your own talent, ability and hard work vs. the shoes. You would have run slower without the shoes so make sure not to take ALL the credit. That being said, personally I’m curious to see how much faster I could run in a pair of shoes like this!
Also understand that if you do a subsequent race without wearing the shoes, you will give up that advantage and it will be more difficult to get another personal best time unless you do a LOT of training and make significant and real physical fitness gains.
Want to run faster the old-fashioned way, with training and hard work?
I can help you make gains that are real no matter what shoes you’re wearing.
Nicole Sifuentes is a former professional runner and 2-time Olympian, a Certified Strength and Conditioning Specialist and full-time Running Coach for adults of all ages and abilities. Read more about her services, and schedule your free consultation today!