Metaspeed Sky Paris vs Alphafly 3

The Metaspeed Sky Paris is ASICS at full race trim: a carbon racing shoe built for one job, chasing a personal best on the road. It is the cadence runner's racer, the half of the Metaspeed line tuned for runners who get faster by keeping their stride length and turning their legs over quicker, while the Metaspeed Edge Tokyo handles those who lengthen their stride. At 215g with a full-length carbon plate and a 5mm drop, it is light, aggressive and unmistakably a marathon shoe rather than a do-everything trainer. The bouncy, springy foam and stiff plate work together to roll you forward and reward a committed effort. Hold goal pace and it comes alive. Jog it easy and you will wonder what the fuss is about. In our view it sits right at the top of the carbon racing shoe pack alongside the Nike Vaporfly 4, and at £260 it is priced like the elite tool it is.

The Nike Alphafly 3 is the brand's maximalist marathon racer, the carbon racing shoe built to carry you to a road PB and not much else. It pairs a full-length carbon plate with twin forefoot Air pods and a tall slab of ZoomX foam, so you get a ride that is bouncy, propulsive and unapologetically built for going long and fast. At 218g it is not the lightest super shoe on the shelf, but the energy return more than earns the few extra grams once you settle into marathon or half pace. This is a specialist. It rewards a committed forefoot or midfoot strike and a pace you can actually hold, and it feels flat and over-built if you jog it easy. If you want a slightly lighter, more nimble option for shorter races, the Nike Vaporfly 4 is the natural stablemate. For the marathon, though, the Alphafly is the one we reach for.