Science: Nike Alphafly is fastest running shoe…

adidas Adizero Adios Pro 2 comapred to nike vaporflyNike Alphafly really does give you wings – the fastest running shoe


When researchers at Stephen F. Austin State University in Nacogdoches, Tex., looked at many of the current crop of carbon-plated running shoes they found Nike Alphafly, Vaporfly and Asics Metaspeed Sky to be the best. Their definition of best looked at improvements the shoes made to running economy ie how fast and far can be run on a given amount of energy.

Here are the full results:

  1. Nike Alphafly – 3.03 per cent improvement
  2. Nike Vaporfly 2 – 2.72 per cent (Review: here, it’s a good read honest!)
  3. Asics Metaspeed Sky – 2.52 per cent
  4. Saucony Endorphin Pro – 1.48 per cent
  5. New Balance RC Elite – 1.37 per cent
  6. Brooks Hyperion Elite 2 – 0.53 per cent
  7. Hoka Rocket X – 0.08 per cent
  • Asics Hyperspeed (racing flat) – 0.0 per cent

The research paper showed 3 clear winners were at least one per cent better than the best of the rest.

Results: VO2 (ml‧kg-1‧min-1; % change from AHS) was significantly different across shoes. HRX (51.67±2.07) and BHE2 (51.42±1.72) did not differ from AHS (51.71±2.02). While SEP (50.93±1.82; -1.48±0.72%) and NBRC (50.99±1.83; -1.37±0.78%) were statistically better than AHS, they were inferior to NAF (50.13±1.86; -3.03±1.48%), NVF2 (50.29±1.72; -2.72±1.02%), and AMS (50.39±1.71; -2.52±1.08%).

I’ve never run with the Alphafly myself, though, as I say in my review, my Vaporfly 2 shoes are definitely the fastest things I’ve ever put on my feet


  • Whilst these results look valid, you might experience different improvements (or not) to your personal running economy
  • Percentage gains might vary at different paces
  • Lighter running shoes are inherently faster regardless of the carbon plate tech or foam tech (Pebax in Nike’s case)


Look at those savings another way and a 20:00 5k runner will save a whopping 36.36 seconds with Alphafly. It really is a significant improvement. Personally, I said before that the Vaporfly seem to give me about 20ish seconds over 5k at that speed but the study’s 2.72% equates to 32.64 seconds.


The Competiton: Carbon Plate Shoes

These all have carbon plate tech of some sort

  • Adidas Adizero Pro (discontinued)
  • BUY: Adidas Adizero Adios Pro (discontinued) – novel carbon rods and a small carbon plate deliver a fast shoe at all distances. A contender for the best marathon shoe.
  • BUY: Adidas Adizero Adios Pro 2 (current) – novel carbon rods and a small carbon plate deliver a fast shoe at all distances. A contender for the best marathon shoe.
  • BUY: Adidas Adizero Prime X
  • BUY: Asics Metaracer (current) – built more for shorter distance speed over 5k and 10k
  • Asics METASPEED Sky – helps runners who get faster by increasing their stride. Due 2021
  • Asics METASPEED Edge – helps runners who get faster by increasing their stride and cadence. Due 2021
  • Brooks Hyperion Elite (discontinued)
  • BUY: Brooks Hyperion Elite 2 (current) – At £210 this is over-priced and not as good as cheaper shoes. Give it a miss.
  • Hoka’s Carbon X (V1, 2019, discontinued)
  • BUY: Carbon X 2
  • BUY: Hoka Rocket X (current) – At £140 this is a sensible performance all-rounder for training fast and for your B race.
  • BUY: New Balance FuelCell RC Elite – A top-level 5K to marathon racer at £210.
  • BUY: New Balance FuelCell TC – At £180 you would use this in rotation as a training shoe as you aim to use the ELITE version for your Races.
  • BUY: Nike AlphaFly NEXT% 2 A marathon PB shoe that’s more for the masses but rarely in stock and £260. This is heavier, costlier and bulkier than the Vaporfly, possibly less stable too.
  • BUY: Nike ZoomX Vaporfly NEXT% – A soft, super-cushioned ride for your A race, providing it’s on the road. If you can find some restricted stock and have £240 to blow, get a pair. Great for all the longer distances but AlphaFly edges it for a marathon if you have the choice.
  • BUY: Nike ZoomX Vaporfly Next% 2 – Same sole as the Next% and different upper. Different price…CHEAPER at £209. I got a pair for my last HIM.
  • BUY: On Cloudboom – a firm ride for 10k and 5k and probably over-priced at £170
  • BUY: On Cloudboom – a firm ride for HM and Marathon and probably over-priced at £160
  • BUY: Saucony Endorphin Pro – a much, much better choice for a firmer shoe over long distances than the On Cloud. £190
  • BUY: Puma Deviate Nitro Elite £170

Note: All buy links go to the manufacturer/brand site.

Take Out

These new shoes definitely can make keen runners faster, They’re not simply for elite runners.

The study casts a significant doubt in my mind about whether all brands have introduced tech that actually makes you faster. My current detour into adidas adizero adios pro 2, seems to be going alright and I’m glad the study didn’t tell me I’d imagined the speed gains with those. That said, a return to Nike for my next pair of racers looks highly likely as I was considering the Hoka Rocket X (not any more!).


Reader-Powered Content

This content is not sponsored. It’s mostly me behind the labour of love which is this site and I appreciate everyone who follows, subscribes or Buys Me A Coffee ❤️ Alternatively please buy the reviewed product from my partners. Thank you! FTC: Affiliate Disclosure: Links pay commission. As an Amazon Associate, I earn from qualifying purchases.

10 thoughts on “Science: Nike Alphafly is fastest running shoe…

  1. I just got the first edition Vaporfly Next% at an absolute steal. The Gyakusou.

    While i find that the laces are a bit uncomfortable, i can absolutely feel a difference. No doubt I am faster in the shoe. Lower HR at same intensity at every intensity.

    Have not raced in them yet, but they will be on my feet at a parkrun soon.

  2. Which elastic lace is that pictured with your Vaporfly? Do you like it, how has it worked with the Stryd in terms of staying clipped on?

    I train in stability shoes (Saucony Omni series) and have seen upwards of 8% improvement using the Vaporfly %2 on HIM race day. I’d attribute the additional difference to weight savings as you alluded to. I was suggested the Metaspeed Sky last week by BITR as an alternative with more pronation support – happy to see your post on this report as that choice being a good one performance wise!

    1. it was like one of these…quite cheap:
      that was not the exact one i got. the one i got has slightly thinner pins so the strap wobbles in the hole.
      something like this is probably better as it uses your existing garmin/polar/suunto pin. if you don’t have quickfit i guess you could cut off the old band material to expose the pin. i was going to do that on my 935 but never got around to it and so bought a fenix 6 instead

  3. Typo alert : “Prebax in Nike’s case” instead of Pebax 😉

    Interesting comparisons, I wonder why they didn’t test either of the Adidas carbon plated shoes though, the flat Adizero Pro and the stacked Adizero Adios Pro !

  4. In 2021 I almost feel like I really should buy a carbon plated shoe for my next marathon, but all of them are very expensive.

    I’m seeing some good deals in the Adidas Adizero Adios Pro but read some reviews saying it’s more fitting for 10k and HM. What’s your take on this model, since you mention it’s a contender for best marathon shoe?

  5. Placebo or ultra real? The sited study, I read the entire thing, was with 8 elite men doing 5 minute time trials on a treadmill at a 6 minute mile pace. They tested each shoe twice. I wish they had studied “avg runner” who might do a marathon at 8:30 pace to determine if the benefit is more placebo at slower pace or if its even a greater % for less efficient runners. The study indicated that runners with longer strides and slower cadence (170) with greater vertical oscillation (me) had the most gains in efficiency. Placebo or not, the evidence is these types of shoes can provide savings.

Comments are closed.