Nike’s Apex marathon racer stacks four Air Zoom units under the forefoot
Apex, the marathon racer due in January 2027, packs four Air Zoom units into two stacked pairs under the forefoot, the most Air Nike has placed there, and Alphafly 4 runs a pair of the same new unit. A much thinner film can be sealed that way without losing the tensile-fibre structure, and each unit came out 30 percent lighter. Nike’s numbers are up to 40 percent more energy return than Alphafly 3 at more than 10 percent less weight. Durability has not moved either, with Nike’s expectation for Alphafly 4 level with Alphafly 3.
Because it measures the whole system, and Swooshfly shows why, nike will not say how much of that 40 percent belongs to Air,.
“Air is highly tunable,” he says. Schoolmeester calls it “one of the highest-energy-return cushioning technologies we have tested”. “Confidence grew as the process repeatedly delivered consistent results, first in development and then through athlete testing,” he says, though he did not go into how every sealed unit is checked on the line. “Zero-drop is more about the maximum propulsion in the forefoot,” Schoolmeester says. “Stability doesn’t necessarily come from adding more material, it comes from how you use the material you have,” he says. “Air Zoom and foam each offer different ways to tune a ride,” Schoolmeester says. “We do not think we have found the limits of Air yet,” he says.
Nike has spent decades learning what Air can do, and its new racers lean on it harder than ever. It is a confident bet, given that Air Zoom took much of the blame when the Pegasus Premium and Vomero Premium turned out heavier than runners expected. Bret Schoolmeester, Nike’s Vice President of Running Footwear, explains the bet in four words. Nike can engineer a unit’s size, shape, pressure and placement around the ride it wants, and weight turned out to be one more thing it could tune. An Air Zoom unit is a sealed polymer bag of pressurised gas that compresses as the forefoot loads it and pushes back as the runner pushes off. Tensile fibres run between its top and bottom surfaces like tethers, letting Nike pressurise it hard while keeping it flat. Foam slowly packs out, while a sealed unit is designed to hold its behaviour for as long as it is worn. The weight fix came from the way the shell is sealed. Nike used to form the unit with heat and has moved to radio-frequency welding, which uses a high-frequency electromagnetic field to heat certain polymers from within, right at the joint. Getting there took what Schoolmeester has described as urgency and sleepless nights. A lighter unit solved only half the problem. Apex also needed room. World Athletics caps the sole of a road racer at 40mm, insole included, and an 8mm drop maxed out at the heel leaves just 32mm under the forefoot. Apex is zero-drop at 40mm in both places, handing the whole allowance to the forefoot, where the stacked Air sits. Everything else is tuned around that stack. Simulations showed two units on top of each other gave the best balance of energy return and stability. ZoomX LT foam sits beneath them, and above them a comparatively flat carbon-fibre Flyplate pushes load down so the units compress properly. The rocker and the stability come from the geometry of the whole platform, helped by a wider outsole. The zero-drop is worth watching, since a lower drop generally asks more of the calves and Achilles, though wear testers logged more than 160km in Apex. The more accessible racer has no Air Zoom at all and relies on SkyX, a foam of TPU beads steamed to different densities around the heel, plate and forefoot, which Nike compares to tuned Air. Not long ago, Air’s weight was its limit, and a change in the factory moved it. Schoolmeester does not think Nike has reached the next one. You use AI every day. Now get your AI Quotient. Take the AIQ test.