Physical Therapists Using Clinical Analysis To Discuss The Art And Science Behind Running and The Stuff We Put On Our Feet

Post Page Advertisement [Top]

Nike Air Zoom Alphafly NEXT% Initial Review

     Currently, Doctors of Running is in Atlanta for the US Olympic Marathon Trials. As many are aware, Nike provided every athlete that qualified with a free pair of Nike Air Zoom Alphafly NEXT%. Although none of us have qualified (yet), we had the opportunity to take a pair of size 10s (mens)

for a spin from an athlete who has qualified (thank you!). The result is a similar bounce from previous versions, but a much more pronounced bounce and push off from the forefoot thanks to the Zoom Air units and Carbon Fiber Plate. The Nike Alphyfly NEXT% is another step up for the Vaporfly series, also literally as there is a ton more stack height too! Enough puns, here are some initial impressions.

Specifications (
Weight: 7.4 oz (men's size 8.5)
Stack Height: 35mm / 39 mm (forefoot / heel)
Drop: 4mm drop
Classification: Marathon Racing Shoe


     The Nike Alphafly NEXT% trades the prior upper for a full ATOMKNIT upper. This new upper is an extremely breathable but secure thin knit mesh. I was quite surprised to be able to see through the upper, yet when I put it on it felt fairly secure. Sizing wise I was fine with my normal size 10 wearing thick socks, but with racing socks would consider going down a half size as have most of the elite athletes here in Atlanta. This is definitely a try before you buy type sizing, but know most are sizing down a 1/2 size (I would not over a marathon distance). There is plenty of room in the forefoot with a little extra room around the small toe. The knit is secure but far less compression than the NEXT%. The ATOMKNIT upper does a great job of disappearing. I felt secure running in a straight line and did not feel any extra foot movement. Turning however was a little sketchy as my feet began to slide a little, but there is also an influence from the tall stack height and very narrow midfoot. The midfoot is very narrow and snug. I can feel my arch falling into it without much upper support. The heel is also fairly narrow and secure.  There is a heel counter, but it is far less aggressive than the Next%. Most of the stiff heel counter is in the very most posterior part of the shoe. The flaps that come around the side are just reinforced mesh. The heel is very well locked down, so much so that it is hard to get the shoe on and off your foot.


     Nike managed to put even more midsole stack height in the Alphafly NEXT% without increase in weight. The weight feels nearly identical to prior versions (I do not have specs yet). The stack height is noticeably taller than any of the other versions. Fortunately the wide forefoot, Zoom Air pods and plate do a great job of stabilizing the front of the shoe. The heel also has a wider sole, providing a little more stable ride for such a tall stack height. The forefoot air zoom units are a fantastic addition. Combined with what feels like a thicker plate, it feels great to get up on on your toes. The zoom air units provide additional feedback to land farther forward.

     The ride from heel to toe is extremely smooth. The heel is very beveled (curved), providing a very smooth and bouncy heel landing. The forefoot is a bit firmer with the plate and air pods, but still provides a very protective and pushy toe off. The extra stack height does not feel more squishy than previous versions and I suspect that this may be related to increased thickness of the carbon fiber plate (looks as such but not confirmed).


The stability feels surprisingly similar to previous versions despite sitting taller. The wider last (shape) of the forefoot and heel likely provide additional stability, while the wider carbon fiber plate likely contributes to this as well. The midfoot is noticeably narrower and I could feel my foot hanging off the medial side. For those that need additional lock down or stability in the midfoot, this shoe may not be for you. It is offset somewhat by the wider forefoot, but may not be for everyone.

The Nike Air Zoom Alphyfly NEXT% is definitely a marathon shoe. I would not wear this for less than a half marathon. The bulkiness is nice for protection, but for picking the legs up at high speed it can be done but there are better shoes for it. Strides in this shoe make this very apparent. I would rather take the NEXT% out for shorter distances and the Alphafly NEXT% for longer distances given the additional cushioning. The shoe is very responsive and can move really fast, however the bulk makes it a little less versatile than previous versions.


     The Nike Air Zoom Alphafly NEXT% has arrived for many elite athletes at Atlanta, for some of us February 29th and will continue to debut during later dates. This is the evolution of the vaporfly series and is a fantastic one at that. The addition of Zoom Air units provides additional protection and responsiveness in the forefoot, while a new ATOMKNIT upper provides amazing breathability and surprising lock down when in running in a straight line. Despite a large increase in stack height, the ZoomX continues to feel responsive and a wider sole maintains some stability despite the narrow midfoot. For those looking for a very cushioned marathon shoe, you will have to check this shoe out on the 29th. I am excited for the many new carbon fiber plated shoes coming out and look forward to continued innovation in racing shoes.

Thanks for reading!

Editor's Note: As always, the views presented on this website belong to myself or the selected few who contribute to these posts. This website should not and does not serve as a replacement for seeking medical care. If you are currently injured or concerned about an injury, please see your local running physical therapist. If you are in the Los Angeles area, I am currently taking clients for running evaluations.

Doctor of Physical Therapy
Board Certified Orthopedic Clinical Specialist
Fellow of the American Academy of Orthopedic Manual Physical Therapists

***Disclaimer: These shoes were not purchased and were allowed as a try on at the 2020 Atlanta Olympic US Marathon Trials.  This is only an initial review as we do not yet have a pair. We put at least 50-75 miles on trainers and 10-25 miles on racing flats prior to performing full reviews. My views are based on my extensive history in the footwear industry and years testing and developing footwear. If you are a footwear rep looking for footwear reviews or consultations on development, we are currently looking to partner with companies to assist, discuss and promote footwear models. Partnership will not affect the honesty of our reviews.

Like and Follow Doctors of Running
Facebook: Doctors of Running  Twitter: @kleinruns
Instagram: @doctorsofrunning Direct Contact:

Please feel free to reach out, comment and ask questions!

Bottom Ad [Post Page]

// ]]>