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How Running Shoes Have Evolved, From Ancient Greece to a Record-Breaking Marathon Time

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How Running Shoes Have Evolved, From Ancient Greece to a Record-Breaking Marathon Time

When the messenger Pheidippides ran from the battlefield of Marathon to Athens to announce the Greek victory over the Persians in the 5th century B.C., he did it without shoes. His time was not officially tracked.

Millenniums later, at the London Marathon on Sunday, Sabastian Sawe and Yomif Kejelcha became the first to break the two-hour barrier in an official marathon, and Tigist Assefa set a women’s world record. All three did it in featherweight footwear.

The shoe, the Adidas Adizero Adios Pro Evo 3, weighs 97 grams, or about 3.4 ounces, depending on the shoe size. It’s the lightest running sneaker approved for competition. It sold out on Monday.

The race to near-weightlessness has been a driving force of innovation in running sneakers in the 25 centuries since shoeless Pheidippides’s run.

Heavier shoes are slower, a 2016 study showed, although that analysis was only for three-kilometer time trials. The study’s authors hid lead pellets in some Nike racing shoes and didn’t tell the subjects.

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“When we added 100 grams per shoe, they ran about 1 percent slower, and when we added 300 grams, they ran about 3 percent slower,” said Rodger Kram, an emeritus professor of integrative physiology at the University of Colorado, Boulder. He called the 1 percent per 100 grams “a rule of toe.”

But it took many steps before running shoes evolved to the blistering pace they now allow.

Shoes once relied on leather, wood or metal reinforcements that were heavy and stiff. The rise of the rubber sole added flexibility and waterproofing. Better durability and grip were bonuses.

People could also run or walk in rubber soles without being heard. That’s why they’re called sneakers.

The first flat-soled rubber and canvas shoe was developed in 1868, almost 30 years after Charles Goodyear discovered the process of curing rubber called vulcanization. Converse and Keds made them popular in the 1920s.

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“Converse All Stars are the Platonic ideal of the sneaker,” said Nicholas Smith, the author of “Kicks: The Great American Story of Sneakers.”

He noted they have not changed much.

“Canvas on top, rubber at the bottom.”

Competitive runners soon faced a trade-off: a heavier shoe with better traction or a lighter flat sole.

The heavier option, which transferred maximum force from the runner’s foot to the ground for acceleration, came from J.W. Foster of Bolton, England, who had the insight that led to the first metal spikes in shoes in the 1890s. Top British runners, including those competing in the 1924 Paris Olympics, wore these new spikes to notch their fastest times. Their story is told in “Chariots of Fire,” the Oscar-winning 1981 film.

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It was at another Olympics, in Berlin, that Jesse Owens wore six-spiked shoes created by Adidas to become the most successful runner of the 1936 Games. His shoes, made of specially tanned calf leather and cowhide, weighed 201 grams.

Running tracks made of urethane, a rubber compound, began to emerge in the 1960s. When one was installed in 1969 at the University of Oregon, the track coach, Bill Bowerman, found that runners’ spikes dug in too deep while flat shoes offered too little traction.

Having breakfast one morning in 1971, he noticed that the grid pattern on the waffle iron his wife was using might just be what his runners needed to get a grip on the track.

He tried pouring liquid urethane into the waffle iron, but only managed to seal it shut. He kept trying other waffle irons until he had the mold he wanted, according to Nike archivists.

But Bowerman wanted more than grippier sneakers.

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“He was also devoted to making the lightest running shoe possible,” said Elizabeth Semmelhack, the author of “Out 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 out of nylon.”

The light weight also helped bring running to the masses.

“You can bet there wouldn’t be so many people running today if they had to carry all the extra baggage we had back then,” Bowerman, a Nike co-founder, said in 1979.

The waffle-pattern nubs on the soles compressed under weight and helped bring spring to a runner’s step. But they only hinted at how sneakers could be cushioned. For many runners, it was not enough.

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Then Nike introduced ethylene-vinyl acetate, better known as EVA foam, on the heel of its Cortez shoe in 1972. EVA offered a thicker, air-infused layer of separation from the road and absorbed more of the shock. The age of adding thick slabs of rubber for cushioning was over.

That led to a new quest that continues today: How much cushioning can you build into a shoe?

Sneaker makers next turned to a gas and a semisolid to help spread the energy of a foot’s impact with the ground.

In 1979, the Nike Air Tailwind began the airbag era, in which pressurized gas is stored in a flexible urethane bag within the sole.

Asics pioneered gel cushioning technology in 1986 with its silicone-based shock absorption. Nike countered in 1987 with the Air Max 1, which had a “window” in the sole designed to show off the air pocket. “At the time that was the cutting edge,” Mr. Smith said.

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Though air is lighter than foam, it had to be kept in a rubber vessel, which added weight. So did adding silicone gel packets to the heel and forefoot.

While air bubbles felt more springy, and gel more dampening, they both were able to absorb shocks longer than the standard foam.

An icon of the 1990s tackled a different problem: how laces become loosened during a run. Reebok, building upon its wildly successful Pump basketball sneakers, which could be inflated with the press of a button on the tongue, introduced the Instapump Fury, a colorful, open-paneled, split-soled running sneaker.

“The Instapump used an air bladder that could fit your particular foot, the nuances of your own foot, very, very closely,” Ms. Semmelhack said. “Then you didn’t have to adjust any lacing throughout your run or at any time. So it was very innovative.”

But as new technologies made foam lighter, shoemakers soon couldn’t get enough of it.

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One brand, Hoka, wedged so much cushy foam into its soles, beginning in 2009, that the shoes looked swollen. Runners could hardly “feel the ground anymore,” Smith said. The company’s designs helped push amateur runners to chunkier shoes.

But it was the thick-soled Nike Vaporflys that captured the most attention. They came with a carbon-fiber plate in the midsole that was very light and gave stability to all the squishy foam. The plate stores and releases energy with each stride, and is meant to spring runners forward.

The Vaporflys also use polyether block amide, or PEBA, a bouncier, lighter foam. The twin technologies led to the nickname “super shoes.”

“There was concern that this additional innovation in the running shoe was the equivalent of doping,” Semmelhack said. The shoes cushioned the feet of all three medalists in the men’s marathon at the 2016 Rio de Janeiro Olympics. The New York Times found in 2019 that the shoes gave a significant advantage, but they were never banned.

Adidas used its lightest foam in the sole of the Adizero Adios Pro Evo 3, which were worn by Sunday’s record-breaking marathoners. It also said that the shoe has carbon fiber rods to mimic the human foot’s bone structure.

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In other words, closer to the bare feet in Pheidippides’s run.

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Caltech could lose control of JPL for the first time

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Caltech could lose control of JPL for the first time

The contract for management and operation of NASA’s Jet Propulsion Laboratory will be opened up to a competitive bidding process for the first time in its history, the space agency announced on Friday.

The action forces Caltech to compete for control of the La Cañada Flintridge institution it has managed since NASA’s inception in 1958.

“The rapid growth of the U.S. space economy indicates there may now be a viable competitive market for programmatic and institutional elements,” NASA said in a statement. “This decision is part of a broader governmentwide and agency effort to find efficiencies, strengthen performance, and drive mission outcomes faster and more affordably.”

In a joint statement, Caltech President Thomas F. Rosenbaum and JPL Director Dave Gallagher said that the announcement came as “no surprise” and that it already had a team in place “to ensure we are positioned for success” in the bidding process.

“Over the course of our nearly seven-decade-long partnership with NASA, Caltech and JPL have led humanity’s exploration and understanding of the universe — and our place within it,” the Pasadena university said. “The ambitions ahead — no less bold than those we have already realized— are ones we are fully prepared to meet.”

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The competition for the contract is part of a slate of changes NASA Administrator Jared Isaacman announced on Friday, including a massive reorganization of the space agency intended “to concentrate resources towards the highest priority objectives in the National Space Policy and liberate the best and brightest from needless bureaucracy and obstacles that impede progress,” Isaacman wrote in a letter to the agency’s roughly 18,000 employees.

JPL was founded by Caltech researchers in 1936, and became part of NASA when the space agency was formed in 1958. Its current 10-year contract with NASA, which is valued at up to $30 billion, runs through Sept. 30, 2028.

Times staff writer Noah Haggerty contributed to this report.

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Feds declare Eaton fire was a cleanup success. Their testing shows otherwise

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Feds declare Eaton fire was a cleanup success. Their testing shows otherwise

Despite finding nearly one in five homes had excessive levels of lead, the U.S. Environmental Protection Agency this week claimed that recent soil testing in Altadena proved that expedited federal cleanup efforts had effectively removed toxic ash and debris from homes destroyed by the deadly Eaton fire.

Earlier this year, the EPA announced it would perform a limited soil sampling at 100 destroyed homes across the burn zone in order to verify that contractors had thoroughly mitigated toxic substances. In a recent news release, the EPA said that testing revealed median lead concentrations below federal standards, and “confirmed that cleanup methods successfully addressed contamination and verified cleanup protocols.”

The EPA soil sampling comes amid mounting pressure from residents and environmentalists who claim that a hasty federal cleanup effort had left behind or spread hazardous fire debris. Internal government reports also raised questions about the thoroughness of the cleanup.

The EPA did not release its report to the public, but it said 95 of 100 soil samples collected near the surface of the home’s building footprint were below the federal lead screening level.

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“I think for the folks in Altadena who maybe had some concerns about the adequacy of the work that was performed by the federal government in removing ash and debris — I think they should feel confident that those areas of their property are safe to use now,” said Mike Montgomery, EPA Superfund and emergency management director.

In announcing its findings, the EPA cited federal lead standards only, and not California’s more stringent thresholds. Of the 100 homes sampled, 17 had lead levels above 80 milligrams per kilogram, California’s benchmark for residential properties. The highest concentration of lead was 705 milligrams per kilogram — nearly nine times higher than the state standard and triple the federal threshold, according to a copy of the report that was reviewed by The Times.

The results unnerved some Altadena residents, who see more and more fire-destroyed homes being rebuilt. Joy Chen, executive director of Eaton Fire Survivors Network, called on federal officials to release the full report and provide additional resources to address elevated contamination.

“From the beginning, people have been very worried that they [federal workers] did not thoroughly clear these sites. Now 16 months later, people are taking it upon themselves to test or bioremediate to ensure it’s safe to rebuild. Most of us don’t have the resources to make those decisions,” Chen said.

“It would’ve been much easier if homes had been cleared to safe levels the first time around.”

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EPA officials said the agency had notified Altadena property owners of their soil test results and encouraged them to review local public health guidance. Montgomery said EPA officials would proactively reach out to property owners whose lots had lead levels above the federal benchmark of 200 milligrams per kilogram.

Federal disaster officials say that some toxic substances within the burn zone could have been deposited there long before the fire — the result perhaps of decades of burning leaded gasoline or lead paint.

The Federal Emergency Management Agency had refused repeatedly to pay for post-cleanup soil testing and broke from long-standing California fire recovery protocols that are intended to protect returning residents from toxic substances. FEMA, along with the U.S. Army Corps of Engineers and the EPA, had touted the fire recovery as the fastest in modern history.

Disaster crews removed millions of tons of fire debris from nearly 9,700 properties affected by the Eaton and Palisades fires in roughly eight months.

But hundreds of disaster victims had complained about substandard work from federal cleanup workers, and internal government reports said crews had left debris behind and, in at least one instance, dumped ash on a neighbor’s property.

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In January — shortly after the one-year anniversary of the fires — the EPA announced that it would perform soil testing for lead at 100 randomly-selected homes that were destroyed in the Eaton fire and later cleared of debris by federal contractors. The announcement followed months of criticism that federal cleanup workers had mishandled debris — including dumping fire debris and contaminated pool water on neighboring properties.

The Los Angeles Times collected soil samples in March 2025 and published the first evidence that already-remediated home sites retained elevated levels of toxic substances. Los Angeles County, UCLA, USC and several other organizations launched their own soil testing efforts, and all found elevated levels of lead at homes that had already been remediated by federal cleanup crews.

Lead is a potent neurotoxin that can stunt the brain development and lead to behavioral issues in young children that inhale or ingest it. When the Eaton fire burned through Altadena’s historic neighborhoods, it destroyed many homes that were coated in toxic lead paint. Plumes of smoke and ash then deposited the heavy metal across the burn zone.

Dr. Nichole Quick, chief medical advisor for the Los Angeles County Department of Public Health, encouraged property owners to seek further testing if they have concerns about contamination, including free testing services provided by local universities.

Quick said residents can take steps to limit their exposure, such as washing dusty equipment and keeping cleaning floors and other surfaces clean.

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“Guidance is really geared towards how you interrupt that ingestion exposure, so we’re talking about a high-risk group, our kids with developing brains, pregnant women,” Quick said. “Kids also happen to be the ones that crawl around on all sorts of stuff and hands directly into mouth, so a lot of what we’re talking about is stopping that sort of exposure.”

Environmental experts quickly questioned the EPA’s soil sampling approach, which drastically differed from soil testing procedures from California environmental agencies. Andrew Whelton, a Purdue University researcher who has studied environmental risk following disaster, said the EPA sampling — which only tested one mixed sample — would likely mask heavily polluted areas of the home. The agency also only tested for lead — one of 17 toxic metals typically tested for following wildfires.

“It’s apples and oranges,” Whelton said. “They [the EPA] only looked for lead and didn’t look for hot spots. The approach that EPA differs from everything that California has done for fire cleanup for the last 15 years.

“My advice to property owners who haven’t tested soil or are adjacent to the fire area is conduct soil testing as it has always been done.”

The EPA and L.A. County health department are expected to discuss the soil testing results at the Altadena town council meeting on June 16.

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How a SoCal native became one of NASA’s most valuable assets

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How a SoCal native became one of NASA’s most valuable assets

One of NASA’s most valuable assets is a Southern Californian.

Following the space agency’s successful Artemis II mission around the moon last month, Victor Glover — who grew up primarily in the Inland Empire and has spent much of his career at Southern California’s many military and aerospace hubs — is now the only pilot to have flown NASA’s Orion capsule.

As the crew finishes its international victory lap before the media, Glover is preparing to put his head down and get to work training the Artemis generation of moon-faring astronauts.

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“I think Artemis is going to demand us to change the paradigm,” he told The Times.

The International Space Station, which has been continuously inhabited by a revolving crew of astronauts in low Earth orbit for over 25 years, has a “very well-worn” training program, he said. But developing a new instructional regimen for complex high-stakes moon missions as the agency tries to aggressively ramp up Artemis launches from once every 3 1/2 years to every six months is a different beast.

“Until we get really ramped up and have a solid training program, I think astronauts need to take more ownership of the training and be involved so we can share this experience,” Glover said.

As of today, the list of Artemis astronauts is only four people long. And the list of Artemis pilots has only one name: Victor Glover.

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Glover, 50, was born in Pomona, graduated from Ontario High School and lived “all over” Southern California’s urban sprawl, including Baldwin Village (which he instinctively referred to by its pre-1988 name, “The Jungle”). He completed his undergraduate studies at Cal Poly San Luis Obispo and received graduate degrees (plural) from the Naval Postgraduate School in Monterey and the Air Force Test Pilot School at Edwards Air Force Base.

He cut his teeth as a test pilot at Naval Air Weapons Station China Lake, in the Mojave. After NASA selected him as an astronaut, he learned to fly SpaceX’s Dragon capsule at the company’s then-headquarters in Hawthorne before riding it to the ISS.

Glover particularly misses those test pilot days, when he was pushing the limits of the F/A-18 Hornet and Super Hornet in China Lake while completing a master’s degree on the side.

“That was actually maybe one of the best times of my career. We had our fourth daughter while we lived in China Lake,” he said. “I was … working really hard but having a ton of fun at a house full of kids.”

In one of Glover’s favorite pictures, snapped by his wife, he is sitting at his desk in his tan desert flight suit, focused on graduate school work while holding one of his daughters.

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Glover sees himself as just one example of how the Golden State’s deserts and coastal cities have left a lasting mark on America’s space program.

“Southern California is very uniquely postured to help NASA,” Glover said. “Southern California has the combination of culture and technology — and it doesn’t hurt to have Hollywood” to help share NASA’s mission and values.

(Glover fondly recalled his joy seeing the “Iron Man” production crew, including actor and rapper Terrence Howard, roll through Edwards Air Force Base during his tenure.)

Glover, who now lives in Texas near NASA’s Johnson Space Center, is focused on bringing that SoCal sensibility and invaluable experience piloting the Orion capsule to the agency’s astronaut training program.

When asked if he hopes to fly again on an Artemis mission, he gave a simple answer: “No.”

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There was one other thing on his to-do list, though.

“Tell L.A. I love them and all of Southern California — and I can’t wait to get back out there and visit my home state and my hometown.”

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