Four per cent does not sound like much. But in a marathon, four per cent is five minutes — the gap between standing on the podium and disappearing into the crowd. In 2016, a shoe company it had built a running shoe that could save exactly that much energy. Runners rolled their eyes. They had heard promises like this for decades, and most turned out to be advertising.
This time a group of scientists decided to check. They asked eighteen to run on a treadmill in three different shoes, and they how much oxygen each runner used at the same speed. Oxygen use is a fair way to compare shoes, because a runner who needs less oxygen is spending less to cover the same ground.
The runners did not know which shoe was which. This detail matters more than it looks. If you believe a shoe is fast, you push a little harder without meaning to, and the stops telling you anything about the shoe. Hiding the brand is how the scientists kept the honest.
The numbers came back close to the company's claim. On average the new shoe energy cost by four per cent, and every single runner improved in it. The carbon plate was part of the story, but the softer foam mattered too. Both work by more of the energy that a runner puts into the ground on each step.
Then the arrived from the road. In the four years that followed, the marathon world fell again and again, and a large share of the fastest times were run in shoes of this type. A single lab study can be wrong. A pattern this size across thousands of races is much harder to explain away.
That success created a problem. If one company sells the and others cannot match it, the race starts measuring shoes instead of runners. Officials argued about it for a year. In the end they did not the shoes. They wrote a instead: the sole may be no thicker than forty millimetres, and the shoe must be on sale to the public.
So can shoes make you faster? For an elite marathon runner, four per cent is roughly five minutes, which is enormous. For a student running eight hundred metres at school, the under your foot changes almost nothing, and your training changes almost everything. The honest answer on who is asking, and that is usually a sign that the question was too simple to begin with.
There is one more thing worth noticing. The scientists did not that the shoe wins races. They proved that it lowers the energy cost of running at a fixed speed. Those two sentences sound alike and they are not the same claim, and telling them apart is most of what science reading asks of you.
