For the better part of five years, the running shoe industry trended relentlessly upward — literally. Stack heights climbed from the low 30s into the mid-40s as brands chased the cushioning and energy return benefits of thicker midsoles. But in 2026, a quiet reversal is underway. Several of the year's most acclaimed new shoes have arrived with stack heights below the 40mm mark that had become the de facto standard, and the shift reflects a genuine reassessment of what runners actually need underfoot.
The reasons for the correction are both biomechanical and regulatory. World Athletics' shoe stack height limit of 40mm for road racing has been in place since 2020, but for years brands continued to push daily trainers and tempo shoes well above that threshold, reasoning that training shoes were not subject to competition rules. Now, a growing body of research suggests that excessively high stack heights can compromise proprioception — the body's ability to sense its position relative to the ground — and may contribute to ankle instability, particularly on uneven surfaces.
Several of 2026's best-reviewed shoes illustrate the trend. The Hoka Mach 7 dropped 3mm of stack compared to its predecessor while maintaining ride quality through improved foam density. The New Balance FuelCell Rebel v5 came in at 36mm, down from 40mm in the v4, and reviewers praised the improved ground feel and responsiveness. Even Nike, the brand that started the super shoe revolution with the original Vaporfly, has trimmed stack heights across its Pegasus and Vomero lines.
The shift does not mean maximalism is dead. Brands like Hoka and Altra continue to offer high-stack options for runners who prefer that ride, and the ultra trail category still favours generous cushioning for the demands of multi-hour efforts on technical terrain. But for the average road runner choosing a daily trainer or tempo shoe, the message from the industry in 2026 is clear: more foam is not always better, and the optimal shoe finds a balance between cushioning and the natural feedback that keeps runners connected to the surface beneath their feet.