When the messenger Pheidippides ran from the battlefield at Marathon to Athens to announce the Greek victory over the Persians in the 5th century BC, he did so without shoes. His time was not officially tracked.
A millennium later, at the London Marathon on Sunday, Sabastian Sawe and Yomif Kejelcha became the first to break the two-hour mark in an official marathon, and Tigist Assefa set the women’s world record. All three managed it in feather shoes.
The shoeThe Adidas Adizero Adios Pro Evo 3 weighs 97 grams, or about 3.4 ounces, depending on shoe size. They are the lightest competition-approved running shoes. It was sold out on Monday.
The race to near weightlessness has been the driving force behind innovation in running shoes in the 25 centuries since Pheidippides’ barefoot running.
Heavier shoes are slower, and 2016 study showed, although this analysis was only for three kilometer time trials. The study authors hid lead pellets in some Nike racing shoes and did not reveal this to the subjects.
“When we added 100 grams to the shoe, they ran about 1 percent slower, and when we added 300 grams, they ran about 3 percent slower,” said Rodger Kram, professor emeritus of integrative physiology at the University of Colorado, Boulder. He called 1 percent per 100 grams “the rule of thumb.”
However, it took many steps for running shoes to evolve to the pace they now allow.
“Platonic Ideal”
Shoes once relied on leather, wood, or metal braces that were heavy and stiff. An increase in rubber outsole added flexibility and water resistance. The bonus was better durability and grip.
People could also run or walk in rubber soles without being heard. That’s why they’re called sneakers.
The first rubber and canvas shoe with a flat sole was developed in 1868, almost 30 years after Charles Goodyear discovered a process of curing rubber called vulcanization. Converse and Keds made them popular in the 1920s.
“Converse All Stars they’re the Platonic ideal of sneakers,” said Nicholas Smith, author of “Kicks: The Great American Story of Sneakers.”
He noted that they hadn’t changed much.
“Canvas on top, rubber on the bottom.”
“Chariots of Fire”
Competitive runners soon faced a trade-off: a heavier shoe with better traction or a lighter flat sole.
A heavier variant that transferred maximum force from the runner’s foot to the ground for acceleration came from JW Foster of Bolton, England, who had the insight that led to the first metal spikes in shoes in the 1890s. The best British runners, including those who competed in the 1924 Paris Olympics, wore these new spikes to achieve their fastest times. Their story is told in the 1981 Oscar-winning film “Chariots of Fire.”
It was at the next Olympics in Berlin that Jesse Owens wore it shoes with six spikes created by Adidas to become the most successful runner of the 1936 Games. His shoes, made of specially tanned calfskin and cowhide, weighed 201 grams.
Broken waffle iron
Running tracks made of urethane, a rubber compound, began to appear in the 1960s. When one was installed in 1969 at the University of Oregon, track coach Bill Bowerman found that runners’ spikes dug in too deep while flat shoes offered too little traction.
While eating breakfast one morning in 1971, he noticed that the grid pattern on the waffle maker his wife was using might be just what his runners needed to get traction on the track.
He tried to pour liquid urethane into the waffle maker, but only managed to seal it. He tried other waffle makers until he had the shape he wanted Nike archivists.
But Bowerman wanted more than grippier sneakers.
“He was also dedicated to making running shoes as light as possible,” said Elizabeth Semmelhack, authorOut of the Box: The Rise of Sneaker Culture.”
Bowerman’s shoe, which Nike called the Waffle Trainer, “stands out because it had an extremely thin rubber sole, but with a high tread, and then the upper of the shoe was made of nylon.
The light weight also helped bring the run to the masses.
“You can bet there wouldn’t be as many people running today if they had to carry all the extra baggage we had back then,” Bowerman, co-founder of Nike, said in 1979.
Waffle lugs on the soles compressed under the weight and helped bring the runner into step. But they only hinted at how the sneakers could be cushioned. It wasn’t enough for many runners.
Then in 1972, Nike introduced ethylene-vinyl acetate, better known as EVA foam, on the heel of its Cortez shoe. EVA offered a thicker, air-infused layer of separation from the road and absorbed more impact. The age of adding thick slabs of rubber for suspension is over.
This led to a new quest that continues to this day: How much cushioning can you build into a shoe?
Lighter than foam
Sneaker manufacturers then turned to gas and semi-solid matter to help disperse the energy of the foot’s impact with the ground.
In 1979, the Nike Air Tailwind ushered in the era of airbags, in which compressed gas is stored in a flexible urethane bag in the sole.
Asics pioneered gel cushioning technology in 1986 with silicone-based shock absorption. Nike countered in 1987 with Air Max 1which featured a “window” in the sole designed to showcase an air pocket. “It was cutting edge at the time,” Mr Smith said.
Although air is lighter than foam, it had to be held in a rubber container, which added weight. Likewise adding silicone gel heel and forefoot packs.
While the air bubbles were more flexible and the gel more cushioning, both were able to absorb shock longer than standard foam.
The ’90s icon tackled a different problem: how the laces come loose while running. Reebok, building on its highly successful Pump basketball sneaker, which could be inflated with the press of a button on the tongue, introduced the Instapump Fury, a colorful running shoe with an open panel and a split sole.
“The Instapump used an air bladder that fit into your particular foot, the nuance of your own foot, very, very tightly,” Ms Semmelhack said. “Then you didn’t have to adjust any of the lacing during the run or at any time. So that was very innovative.”
The rise of super boots
But as new technologies made the foam lighter, cobblers soon couldn’t get enough of it.
One brand, Hoka, has since 2009 wedged so much soft foam into the soles that the shoes look swollen. Runners could hardly “feel the ground” anymore, Smith said. The company’s designs have helped amateur runners make more robust shoes.
But the Nike Vaporflys with a thick sole caught the most attention. They came with a carbon fiber plate in the midsole that was very light and added stability to all the squished foam. The plate stores and releases energy with each step and is intended to propel the runner forward.
Vaporflys also use polyether block amide or PEBA, a more flexible and lighter foam. Dual technologies led to the nickname “super shoe”.
“There was concern that this next innovation in running shoes was the equivalent of doping,” Semmelhack said. The shoes cushioned the feet of all three men’s marathon medalists at the 2016 Rio de Janeiro Olympics. The New York Times found in 2019 that the shoes provided a significant advantage, but they were never banned.
Adidas used its lightest foam in the Adizero Adios Pro Evo 3 sole worn by Sunday’s marathon record holders. The shoe was also reported to have carbon fiber rods that mimic the bone structure of the human foot.
In other words, closer to the bare feet of Pheidippides’ run.
