The Alphafly has spent six years as the shoe people point at when they argue about whether marathon times still mean the same thing. Kipchoge went under two hours in it. Kiptum set the world record in it. Whatever you think about that, the line has earned its position.
The Nike Alphafly 4 is here, and it is the first version where the headline is not a new shape but a lighter one.
Nike Alphafly 4
Style code: IU4686-002
Colourway: Sea Glass/Laser Crimson-Phantom-Burgundy Ash
Key figures, as stated by Nike: 10 percent more energy return than the Alphafly 3, 5 percent lighter in a men's US8.5
What Nike Changed
Nike describes the 4 as a rebuild of every major component rather than a facelift, and the numbers they have put behind it are unusually specific. Ten percent more energy return than the previous model, and five percent lighter measured in a men's US8.5.
The new element doing most of that work is ZoomX LT foam. Nike puts it at up to 17 percent lighter than standard ZoomX with 8 percent more energy return, and it does not replace ZoomX so much as join it. The two are layered above and below the Flyplate, which is a different approach to simply swapping one foam for another.
The carbon-fibre Flyplate keeps the propulsive scoop that has defined the line, and the dual forefoot Air Zoom units are still there, tuned to work with the foam rather than announce themselves. Underneath sits a Fast Shot outsole, which is where the weight saving tends to come from on shoes like this.
The Upper Is the Quiet Improvement
Atomknit returns, rebuilt. It is fully seamless now, with zoned cables through the midfoot, an integrated heel unit and a moulded sock liner. On a racing shoe that is more significant than it sounds, because the upper is usually where things go wrong over distance rather than underfoot.
Nike's stated goal was not a faster shoe but a shoe that holds its efficiency as fatigue sets in. Emily Farina of the Nike Sport Research Lab put it as years spent studying how fatigue changes running mechanics, and refining the system around that rather than around top speed.
Whether a runner feels ten percent of anything is a fair question. What is easier to verify is that Addisu Gobena won in Sydney wearing it and took the course record, and that the prototype testers have described it as softer and bouncier than the 3 rather than firmer and more aggressive.
Nike Alphafly 4 on KLEKT
The full Nike Alphafly range is live on KLEKT, covering the Alphafly 3 in its Volt Ekiden, Laser Orange and Eliud Kipchoge colourways through to the current line.
Racing shoes behave differently to most of what we sell. Pairs tend to move in size runs rather than one at a time, and the older generations stay in demand far longer than a lifestyle silhouette would, because runners who trusted a shoe once will go looking for it again.
The Nike Alphafly 4 page is worth watching as pairs start to appear, or list yours if you already have a pair in hand.
Check out the Nike Alphafly 4 on KLEKT.
Images: Nike
