Nike has rebuilt its flagship marathon racer from the outsole up, and early testing of the Alphafly 4 suggests the shoe now suits a slightly different runner than its celebrated predecessor.
The Alphafly line carries serious pedigree. Eliud Kipchoge wore the original when he first broke the two-hour marathon barrier in 2019, and again for his 2:01:09 official world record in 2022. Kelvin Kiptum wore an Alphafly when he lowered that record in Chicago in 2023, and Ruth Chepngetich wore one for her 2:09:56 women's world record in 2024. With that history, any redesign invites scrutiny.
The short answer from testing: Nike hasn't ruined it, but it has changed its character. Every component is new, though the silhouette looks much like the Alphafly 3. The headline tweak is in the Air Zoom pods, now sealed by radio frequency instead of heat, which Nike says makes them 30 percent lighter and softer. There's also a reworked ZoomX foam called ZoomX LT, plus a slightly wider carbon plate for stability. The result weighs just 6.6 oz (men's size 8.5) with a 39-31 mm stack and 8 mm drop.
On the road, the differences show up by pace. The Alphafly 4 rides noticeably softer, especially up front, and the Zoom units engage easily even at jogging speeds. That makes it more forgiving at slower efforts and, the reviewer suspects, better late in a marathon when tired legs want cushioning over snap. The trade-off: at 10K pace or faster, it lacks the punchy rebound of the Alphafly 3. For shorter, faster racing, Nike's firmer Vaporfly 4 remains the sharper tool.
The other big win is fit. The old shoe's tight, hard-to-enter upper was a common complaint, particularly as feet swelled over 26.2 miles. The new AtomKnit upper is softer, roomier in the toe box, and far easier to get on.
For anyone travelling to a destination marathon this season, the takeaway is simple: if you race long and like a plush, forgiving ride, the Alphafly 4 looks like the strongest Alphafly yet for the full distance. If your A-race is a half or a fast 10K, the bouncier Alphafly 3 or Vaporfly 4 may still be the better packing choice. It's a genuinely useful update rather than a misstep — just a shoe that has leaned into comfort.
