Nike InfinityRN 4 Review: Corrected Weight and Neutral Support

Nike InfinityRN 4 Review: Corrected Weight and Neutral Support

Disclosure: TrainingPlan has not hands-on tested this exact model. This research-based review uses exact-model manufacturer and independent evidence. No Amazon listing is currently verified for publication.

Quick Verdict

Nike InfinityRN 4 is a high-cushion road trainer with ReactX foam, a Flyknit upper, rocker geometry, and a broad base. It feels conceptually stable because of its shape, but it is not a conventional corrective stability shoe. The corrected men's reference weight is 12.5 ounces—nearly two ounces heavier than the old catalog entry—so comfort and planted transitions matter more here than speed.

Most importantly, this audit removes the former “injury prevention focused” language. Nike's earlier Infinity marketing history does not establish that this shoe prevents injuries for an individual runner. The decision should rest on fit, ride, weight, and use rather than a medical promise.

Key Specifications

Nike's exact product page supports the men's weight, 9mm drop, materials, fit warning, and price. Nike's launch release dates the model to July 2023 and explains the switch to ReactX.

What Changed

The model name is corrected from “React Infinity Run 4” to Nike's InfinityRN 4. Weights move from 10.6/9.2 ounces to 12.5/9.9, stack from 37/28mm to a brand-listed 39/30mm, support from stability to neutral, and widths from standard/wide to standard/extra-wide.

The image is now an exact Nike asset. The article removes all injury-prevention wording and quarantines an unverified Amazon listing. Those are substantive corrections, not stylistic refreshes.

Ride and Intended Use

ReactX is designed as a more responsive successor to React while the broad platform, pronounced heel, and rocker encourage steady forward transitions. Doctors of Running describes it as stable neutral and supplies the brand-listed 39/30mm geometry. RoadTrailRun adds multi-tester context.

The shoe is best aimed at easy running, daily mileage, walking, and long steady outings. Its weight works against fast turnover. For lighter choices, see the best lightweight shoes.

Fit and Sizing

Nike explicitly says the exact model fits small and recommends ordering half a size up. Treat that as a useful starting signal, not an instruction that fits every foot. Compare normal and half-size-up pairs, then check toe clearance, Flyknit pressure, heel hold, and bending comfort.

An exact extra-wide version exists, though availability differs by region and gender. The shoe-selection guide explains how to separate length from width instead of using extra length as a width fix.

What Works Well

• Broad, inherently stable neutral platform.
• Cushioned full-length ReactX midsole.
• Extra-wide exact-model option.
• Waffle-pattern rubber coverage for road use.

Tradeoffs

• Heavy, especially in the men's reference size.
• Small-fit warning complicates online ordering.
• Not designed for fast workouts.
• Independent laboratory stack differs materially from brand-listed geometry.

Who Should Consider This Shoe

Consider InfinityRN 4 if you want a substantial, cushioned road shoe that feels planted without a traditional stability mechanism. It may work in a rotation as an easy-day counterpart to a lighter workout shoe. The daily-trainer guide offers alternatives across weights.

Who Should Look Elsewhere

Look elsewhere if low weight, strong ground feel, or a corrective stability category is essential. The Mizuno Wave Equate 8 offers structured guidance; the Adidas Adizero SL 2 is far lighter and more speed-friendly.

Cross-Brand Comparison

Equate 8 uses a Foam Wave support system and a traditional 12mm selected drop, while InfinityRN 4 uses shape and width to create stable-neutral behavior. Adizero SL 2 weighs roughly four ounces less in men's references but provides less platform breadth.

Same-Brand Comparison

The Nike Vomero 18 is another cushioned daily option with a different foam blend and current lineup role. The Nike Invincible 3 uses ZoomX and a softer max-cushion concept. InfinityRN 4 sits between comfort and stability through geometry.

Value

At MSRP: $160, value depends on specifically wanting ReactX cushioning and a broad platform. The shoe is less attractive as an all-purpose trainer when fast work is common. Extra-wide availability can materially improve its value for runners underserved by standard widths.

Its current status does not eliminate the need to verify region and variant. Nike pages differ by country, and a standard women's listing should not be used to infer availability of every extra-wide size. Confirm the exact InfinityRN 4 name, width label, and return policy. Those checks are more defensible than relying on an old ASIN or the discontinued injury-prevention story.

The lower RunRepeat laboratory measurement of 34.2/24.4mm does not erase the brand-listed 39/30mm; it shows why measurement methods must be labeled. Buyers should focus more on actual fit and ride than a single millimeter ranking.

Final Verdict

InfinityRN 4 is a heavy but purposeful stable-neutral trainer with ReactX cushioning and useful width choice. The corrected review removes unsupported medical marketing, supplies the real reference weights, and discloses its stack conflict so the decision rests on evidence rather than mythology.