Terrex Agravic Speed Ultra 2 vs Ultrafly 1

Adidas kept the second Agravic Speed Ultra fast and fussy, and fixed most of what people disliked about the first. The upper is far comfier than on the original Speed Ultra and the lugs bite harder, and the reviews we read broadly agree most runners will prefer it. It is still a trail racing shoe with a narrow heel, a pointed toe box and a rocker that wants you up on your forefoot. Women's Running UK gave it five stars as an ultra racer for runners who put speed and control ahead of plush cushioning. On our spec sheet it is effectively zero drop, and lab testing says the heel rocker makes it feel less flat than that. At a £200 RRP it sits alongside the S/Lab Genesis 2 and Tecton X 3 as a race-day trail shoe. If you land midfoot and race on fast, runnable trails, we'd pick it over both. Heel strikers and wide feet should look elsewhere.

The Nike Ultrafly 1 is Nike's first proper carbon trail racer, and it plays like a road super-shoe that has been sent to the mountains. A full-length ZoomX midsole gives you that soft, springy super-foam return, a carbon plate stiffens the ride for the climbs, and a Vibram Megagrip outsole handles the wet rock and mud that would leave a road plate helpless. This is a running shoe built for one job: going fast on trail race day. At £225 it sits at the very top of the market, up against the Hoka Tecton X 3 and Salomon's S/Lab racers, and it is best kept for hard efforts rather than daily miles. On smooth, rolling and moderately technical trail it feels quick and protective. On steep, rooty, gnarly ground the tall stack and stiff plate ask for confident, committed footwork. Buy it as a specialist trail marathon and ultra weapon, not an everyday trail trainer.