The Nike Alphafly has been one of the best carbon-plate running shoes you can buy since the original launched in 2020, and the Alphafly 3 set both men’s and women’s marathon world records.
In the time since the Alphafly 3 came out in early 2024, however, a slew of outstanding rival super-shoes from other brands have come out, with the most notable being the Adidas Adizero Adios Pro Evo 3.
The Pro Evo 3 was used by Sabastian Sawe to run the first sub-2-hour marathon in an official race in April at the London Marathon — seven years after Eliud Kipchoge did it at a special event in a prototype of the original Alphafly.
There’s some pressure on the Nike Alphafly 4 then, which launches today and needs to be both better than its illustrious predecessors and the best racers from other brands.
To find out how Nike went about updating its flagship marathon racing shoe, I spoke to Bret Schoolmeester, Vice President overseeing Nike Running Footwear, and to my surprise, one of the major focuses in the development of the shoe was stability.
What were the aims going into creating the Alphafly 4?
Nike leaned on both its extensive roster of elite athletes and its research teams to create its aims for the Alphafly 4.
“The benefit we have in our racing line is we have the voice of our athletes telling us ‘hey, here's some things we want’, and we also have our lab team being pretty consistent that there's an evergreen benefit that we always need to keep pursuing, and that's how do we improve runners’ running economy; how efficiently they can run in the shoe,” says Schoolmeester.
“There’s things we know we're never going to stop pursuing, like weight reduction and energy return, and then one thing we did uniquely focus on with the Alphafly 4 is stability.”
One thing we did uniquely focus on with the Alphafly 4 is stability
Bret Schoolmeester, Nike Running
Improving stability is tricky in a modern racing shoe, most of which uses tall stacks of soft foams, but it can be important in the latter stages of long events in particular.
“Late in a race, your biomechanics break down,” says Schoolmeester. “The better you're supported, the more you're going to be able to hold that critical velocity all the way through the race.
“That was a really big one for us, because it came from our kind of everyday athletes, but it's also trickled up into the elites.”
Trickled up is not a phrase I often hear when covering super-shoes — usually the benefits aimed at elite athletes trickle down to amateurs — but Nike is keen to position the Alphafly 4 as a racer for all levels.
“What we're really proud of with the Alphafly overall is that while it's the franchise that helped break the two-hour marathon for the first time when Eliud did it, it's also the most widely adopted marathon racing shoe. From the front of the pack all the way to the back, we see Alphaflys on everybody's feet.”
What are the key updates to the Alphafly 4?
The Alphafly 4 has been updated from the upper to the outsole to help make it 5% lighter and more energetic than the Alphafly 3, and the key updates to the shoe are found in the midsole.
“There’s a new foam — ZoomX LT is a new way for us to process ZoomX, so we can get that 17% weight reduction while still improving energy return by 8%,” says Schoolmeester.
Nike also changed the design of the Air Zoom pods in the forefoot of the shoe, switching from a thermoformed bag to radiofrequency welding, to reduce weight by 30%.
“Then the plate,” says Schoolmeester. “The plate has always had this really scooped geometry to help with propulsion. We switched up the geometry to make sure it was also adding to stability, maximising the deflection of the foam and the airbags.”
Along with the new ZoomX LT foam, the Alphafly 4 also uses standard ZoomX in its midsole, a setup that Schoolmeester suggests boost both performance and stability.
“That’s one of the things we worked through in the development process,” says Schoolmeester. “Should we go with both foams? Should we switch the configuration?
“What we found was that using ZoomX on the bottom midsole part, which still offers incredible energy return and weight, helped stabilize the system, whereas with the top part we put a heavier premium on lightweight and energy return.
“It maximized both of those different components, and that wound up being the best performing system.”
Why is stability important in a marathon racing shoe?
I’ve tested a lot of pinnacle racing shoes and rarely is stability given such prominence as it is with the launch of the Alphafly 4, but it's an important feature that shouldn’t be overlooked.
“Energy return: no-brainer. Lightweight: no-brainer. But stability in a racing shoe; people don't consider it as necessarily being really important,” says Schoolmeester.
“But watch any marathoner — even the world's best — their mechanics don't always look exactly the same towards the end of the race, and especially for us mere mortals, you're going to need some extra support.”
Energy return: no-brainer. Lightweight: no-brainer. But stability in a racing shoe; people don't consider it as necessarily being really important
Bret Schoolmeester, Nike Running
That extra support can directly lead to you running faster, which is ultimately what these super-shoes are all about.
“If you're fighting the shoe at all, or fighting to stay stable, that's energy that's not being put into going straight forward as fast as you can,” Schoolmeester.
“We intentionally fatigue athletes and run tests to make sure that the benefits are holding up even when fatigued, because feeling good mile one through five, any marathoner will tell you, is not the hard part.
“Feeling good at 30km, 35km (18 miles, 21 miles) and holding everything together all the way through to the finish line. That's the real magic.”
The Nike Alphafly 4 costs $275/£254 and will be available as a limited release from 17 September, with broader availability from 29 October.
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