Puma Velocity Nitro 5 vs Puma Velocity Nitro 4:
Which to Choose

The headline difference is the foam. The Nitro 4 runs on a single layer of nitrogen-infused NITROFOAM that reads as lively and lightly springy rather than plush — it firms up when you push the pace and gives a very connected, honest ground feel, but at slow jogs it can read firm rather than cradling. The Nitro 5 switches to an ATPU-based NITROFOAM that feels softer on contact and springs back more readily, trading a little of the 4's immediate, firm snap for a more compliant, bouncier ride that rewards picking up the tempo. The second big change is geometry: by caliper the Nitro 4 sits on a 34 mm heel / 24 mm forefoot stack for a traditional 10 mm drop that favors heel strikers and eases the calves, while the Nitro 5 measures 31 mm heel / 26 mm forefoot — a lower, roughly 5 mm drop that encourages a more midfoot-friendly, natural stride and keeps good ground feel. Weight runs counter to what you might expect from the softer foam: the Nitro 4 is the lighter of the two at about 224 g in a men's US 9 versus roughly 238 g for the Nitro 5, so the predecessor still has a slight edge in pure nimbleness. Everything else is largely shared — both are neutral with a moderately stable platform and no pronation correction, both skip a plate, both lean on NITROFOAM rebound rather than a carbon kick, and both target the same 10K/half/marathon band. The Nitro 5 carries a touch more of an uptempo bias in how it's tuned, while the Nitro 4 is happiest at steady daily pace; neither is a 5K spike-racer or a max-stack recovery cruiser.