Run Smarter (Brodie Sharpe, Physio)

New Research Just Found A Problem with Nike’s Fastest Shoe

The video reviews a 2021 study that literally cut the carbon‑fiber plate out of Nike’s Vaporfly and compared the running economy of 15 athletes in the altered shoe versus the intact version. Results showed no statistically significant energy savings from the plate, shifting the focus to the shoe’s high‑tech foam and aggressive geometry. Researchers highlighted that the PA‑based foam used in Nike’s Alphafly and Vaporfly stores and returns more energy than EVA foams, but that advantage erodes after roughly 450 km of use. The authors quoted the study’s conclusion that “energy savings are likely coming from a combination of the foam, the shoe geometry, and other effects of the plate that aren’t related to its stiffness.” They also warned that abrupt transitions to these shoes can overload the forefoot, increasing stress‑fracture risk, and advised a gradual adaptation schedule. For runners, the takeaway is to reserve the shoes for flat‑road key workouts and races, rotate them to preserve the foam, and recognize that faster athletes gain more benefit while individual responses can range from +5 % to none. Shoe manufacturers may also reconsider emphasizing carbon‑plate stiffness as the primary performance driver.