Mizuno Wave Horizon 8 vs Mizuno Wave Horizon 9:
Which to Choose

On paper these two are almost the same shoe underfoot: both run an 8mm drop on an identical 41mm heel / 33mm forefoot stack, both weigh right around 320g in a men's US 9 (the 9 is a hair lighter than the 8's roughly 323g), both carry the same high stability rating, and both call the long, steady run their sweet spot. The differences are in what's inside that platform. The biggest change is guidance: the Horizon 8 relies on Mizuno's signature nylon Wave plate — a composite element that physically organizes each landing and keeps the soft foam in check — while the Horizon 9 drops the rigid plate entirely and steers with a foam-based FOAM WAVE geometry instead. That shifts the character of the ride. The 8 feels calm and composed, with the plate keeping transitions crisp and controlled even as you tire; the 9 leans more purely on foam, adding a plush, responsive Enerzy NXT top layer over a firmer Enerzy base so landings feel softer and a touch livelier before settling onto the stable platform below. That foam change nudges the 9 to maximum cushioning and slightly higher responsiveness than the 8. The upper changes too — the 8's engineered mesh gives way to a stretch-woven upper with a gusseted tongue on the 9. Neither is built to go fast: the 8 tops out effectively around 5:00–5:15 min/km, the 9 is happiest a notch more relaxed at 5:30 min/km and up, and both feel like more shoe than the pace needs if you try to sprint.