Does deconstructing the Nike Vaporfly 4% affect running mechanics?

The running economy improvements observed in the Nike Vaporfly 4% (VP4) shoe have been proposed to be a result of different specific features of the shoe, such as the curved carbon fibre plate, forefoot geometry, and the PEBAX (polyether block amide) foam (Hoogkamer et al., 2018). However, until recently, most studies quantified physiological and biomechanical variables in the VP4 alongside previously established running shoes. This approach has not enabled researchers to explain the specific effects of each unique feature of the shoe. In order to understand how and by how much specific feature of the VP4 affect running performance, one must first quantify, how and how much the specific feature of interest affects the biomechanics during running. In a second step one would have to determine the contributions of the mechanical adaptations to running performance using lab based running economy measurements. This study addresses the first part of investigating the mechanical changes produced by systematically affecting the features of the VP4 shoe.