Adizero Adios Pro 4 vs Fast-R Nitro Elite 3

Reviewers mostly liked how the Adios Pro 4 runs, and their complaints were about their toes. On speed they're close to unanimous: softer and bouncier than the Pro 3, a lot lighter, and properly quick once you're at 10k to marathon effort. The Run Testers found it lighter and cheaper than the Alphafly 3, if a little less springy. On fit, the toe box tapers, it runs a little short, and several testers had sore toes by the end of a marathon. So this is a carbon racing shoe for neutral runners with normal to narrow feet who race with some intent, from 5k up to the full distance. It's less happy at jogging pace or under a heavy heel strike. The newer Adios Pro 5 has a lower RRP and more padding at the heel, so check the price table before paying full whack for the older shoe.

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.