Evidence of variable performance responses to the Nike 4% shoe: Definitely not a game-changer for all recreational runners

Abstract

Purpose: We compared running economy (RE) and 3-km time-trial (TT) performances of male recreational runners wearing the Nike Vaporfly 4% (NIKE), lightweight racing flats (FLAT), and their habitual footwear (OWN). Methods: Eighteen male recreational runners [age: 33.5 (11.9) y, V̇O2peak: 55.8 (4.4) mL·kg-1·min-1] attended 4 sessions ~7 days apart. The first session consisted of a V̇O2peak test to inform subsequent RE speeds set at 60, 70, and 80% of the speed eliciting V̇O2peak. In subsequent sessions, treadmill RE and 3-km TT were assessed in the three footwear in a randomised, counterbalanced crossover design. Results: RE was improved in NIKE (3.6 to 4.5%, p ≤ 0.002) and FLAT (2.4 to 4.0%, p ≤ 0.042) versus OWN across intensities, with a trivial difference between NIKE and FLAT (1.0 to 1.6%, p ≥ 0.325). NIKE 3-km TT (11:07.6 ± 0:56.6 mm:ss) was superior to OWN by 16.6 s (2.4%, p = 0.005) and FLAT by 13.0 s (1.8%, , p = 0.032), with similar times between OWN and FLAT (0.5%, , p = 0.747). Only 29% of runners were more economical across intensities and faster in NIKE. Conclusions: Overall, our findings indicate that NIKE could benefit RE in male recreational runners at relative speeds when compared to OWN, but not when compared to FLAT. More runners exhibited better TT performances in NIKE (61%) versus FLAT (22%) and OWN (17%). The high variability in individual RE (-3.1 to 12.1%) and TT (-3.8 to 8.2%) shoe-responses suggests that individualisation of running footwear prescription is warranted.

Technological advances in elite marathon performance

“…In a laboratory setting, the Nike Vaporfly 4% reduced the energetic cost of running among elite male runners by ~4% relative to other contemporary racing shoes (6), hence the shoe's moniker. These initial findings among males were supported (9) and broadened to include independent laboratory testing in females (1) and male recreational runners (5), and analysis of crowdsourced data from recreational runners (24). The Nike Vaporfly series represented several deviations from "conventional" marathon performance shoes, each of which likely contributed synergistically to the 4% reduction in the energetic cost of running: first, embedded carbon-fiber plate (7,26); second, curvature of the carbon plate (23); third, innovative midsole material (28); and fourth, appreciable midsole thickness.…”

“…heavier training vs. lightweight racing shoes). Additionally, withinrunner factors may vary considerably after the purchase of costly and exclusive marathon racing shoes with perceived technological advantages, such as biomechanics (5,7) and training. Thus, elite marathon runners are an ideal model to determine the effect of neoteric Nikes on marathon performance.…”