Embedded in the length of the midsole is a thin, stiff carbon-fiber plate that is scooped like a spoon. Imagined another way, it is somewhat curved like a blade. The plate is designed to reduce the amount of oxygen needed to run at a fast pace. It stores and releases energy with each stride and is meant to act as a kind of slingshot, or catapult, to propel runners forward.
Nike says that the carbon-fiber plate saves 4 percent of the energy needed to run at a given speed when compared with another of its popular racing shoes.
If accurate, said Tucker, the South African sports scientist, that is â€œthe equivalent of running downhill at a fairly steep gradientâ€ of 1 to 1.5 percent.
â€œThatâ€™s a massive difference,â€ he added.
These shoes are providing aided performances in the marathon. There's no denying it.