Background
Joyner et al. [2] evaluated the progression of world record performances in marathon since the late 1920s. On average, a 20s reduction per year since 1960 was found, but since 1980, the average reduction was lower (10s) per year, showing a stagnation in progression. Since the release of this type of footwear (2017), all men’s and women’s world records in long-distance road running events have been broken by athletes wearing new technological footwear [3]. Moreover, it has been suggested that “recent improvements in these events are unlikely physiological but rather technological, if for no other reason that such a step-wise improvement in physiological attributes underpinning performance is unlikely”. A recent meta-analysis [4] confirms that using shoes with increased longitudinal bending stiffness and a curved plate (such as the Vaporfly shoes) implies a technological improvement of ~ 3.45% in running economy (RE). These RE changes provide a ~ 2% improvement in marathon performance [5]. Therefore, the relation between RE improvement and performance is clear.