Mach X 2 vs Zoom Fly 6

Heel rub is the first thing to know about the Mach X 2. Nearly every review mentions it: the heel collar is thin and unpadded, several testers got blisters in the first few runs, and another found it dug into the Achilles. Get past that and the ride is why people put up with it. It's a rockered, snappy super trainer that reviewers took from easy runs to track reps, and Believe in the Run graded its performance an A.

Doctors of Running were less convinced, finding it heavy for fast running and unstable for one of their testers. Hoka has since released the Mach X 3, which reviewers rate more highly, so the 2 makes most sense as a discounted buy. At £180 RRP it's hard to choose over its successor, but check the price table, because an older super trainer at a good discount is a different proposition.

The Nike Zoom Fly 6 is the carbon plate experience for everyone who is not racing. It sits in the super trainer slot: a plated, well cushioned road shoe built to handle tempo work, long runs and the odd race without the price or the fragility of a true marathon flat. At 265g it is no featherweight, and that is the point. Nike has traded the raw speed of its race line for durability and a more forgiving daily ride, so you get the snap of a full length carbon plate stacked on a soft, bouncy midsole that holds up over the miles. If you want the actual race rocket the Vaporfly 4 is lighter and faster, but the Zoom Fly 6 is the one you can train in week after week. We rate it as one of the best value carbon trainers around for runners who want one shoe to cover their faster days.