Alphafly 3 vs Fast-R Nitro Elite 3

Most carbon marathon shoes want strong, well-trained legs before they give much back. The Alphafly 3 asks for less than its looks suggest, and that came through in almost every review we read. Nike made the midsole one continuous piece for this version (the Alphafly 2 had a big gap under the midfoot) and took a lot of weight out. Reviewers describe a smoother roll from landing to toe-off, and it no longer feels clumsy on a warm-up jog. Ben Parkes, who has raced marathons in it, reckons it isn't so aggressive that only elites benefit, and thinks plenty of intermediate marathoners will get a lot from it.

It's still a specialist carbon racing shoe, and at £285 RRP it sits near the top of the market. It's also loud on the road, and some feet find it snug. For 5K and 10K races the lighter, snappier Vaporfly 3 makes more sense. For the half and the full marathon, we'd still put the Alphafly 3 near the front of the queue.

At 170g, the Fast-R Nitro Elite 3 is one of the lighter full-stack carbon racing shoes we track, and most reviewers rank it among the fastest they've raced in. The price of that speed is stability, durability and a ride that only makes sense when you're working hard. That makes it a very good running shoe for a fairly small group: efficient mid and forefoot strikers racing 5K to the half, and quick marathoners whose form doesn't fall apart late on. The Run Testers raced it at the London Marathon and felt it was lighter and more efficient than the Alphafly 3, though never a shoe they stopped noticing. Running Shoes Guru was less taken, marking it down for wobbliness and early wear at this price. At £260 RRP it sits at the top of the market, and Puma's own Deviate Nitro Elite 4 is £45 less if you want a carbon racer from the same range without the Fast-R's quirks.