Running News Daily

Fancy new midsole materials like PEBA make you faster, but at the cost of durability

The eternal question of how long your running shoes should last became suddenly topical a few months ago, when Tigst Assefa set a world marathon record in what Adidas billed as essentially a single-use marathon shoe. This development sparked some important discussions about sustainability, accessibility, and fairness. But it also served as a reminder of how little we actually know about the useful life of running shoes, especially in the new era of thick-foamed super shoes.

Fortunately, there’s some interesting new data in a study from researchers in Spain, led by Victor Rodrigo-Carranza of the University of Castilla-La Mancha. In the Scandinavian Journal of Medicine and Science in Sports, they compare shoes made with a modern super foam to a traditional EVA midsole before and after 280 miles, and find that the new midsole does indeed lose its magic more quickly—so much so, in fact, that the super shoe is no better than the regular shoe at that point.

Before digging into the specifics of the new study, it’s worth sketching in some context. The conventional wisdom that I’ve heard throughout my running life is that shoes typically last somewhere between 300 and 500 miles. This is based on some mix of cumulative experience and imperfect data, some of it published and some presumably locked away in shoe-company filing cabinets.

For example, there’s a 1985 study that measured shock absorption at frequent intervals between 0 and 500 miles, using a machine to simulate the impacts of running as well as two volunteers who racked up 500 real-life miles. Here’s an example of how shock absorption changed with mileage for one particular shoe:

The machine version of running obviously didn’t replicate the demands of in-person running very well, but the two human volunteers show similar patterns. Overall, the human testing found that shoes retained about 80 percent of the shock absorption after 150 miles, and 70 percent after 500 miles. You can see that the curve flattens out between about 300 and 500 miles, which is presumably where the conventional wisdom on shoe lifespan comes from. Conversely, you could argue that once you’re past 300 miles, the shock absorption isn’t going to drop much further, so if you’ve made it that far you might as well keep running in them until they (or you) fall apart. More on that below.

You might wonder whether shock absorption, as measured by a hydraulic machine, is really what matters to runners. More recent research has looked at other metrics: this 2020 study, for instance, used force-sensing insoles to measure the peak pressure on different parts of the foot, testing how it changed as a New Balance 738 shoe went from new, to 215 miles, to 430 miles. As the image below shows, the highest pressures are seen in the midfoot and forefoot:

Those pressures stayed virtually unchanged after 430 miles—but the midfoot peak pressure increased from 388 to 450 to 590 kilopascals, a 50 percent jump. It’s not clear exactly why the midfoot pressure increases. It could be that the relative lack of cushioning in the midfoot makes it less durable; it could be that the higher pressures on the rearfoot and forefoot break down the cushioning in those regions and shift load to the midfoot. Either way, it’s clear that the objective load on the foot has changed after 430 miles. And interestingly, the perceived cushioning reported by the volunteers picked up this change: those who reported feeling less cushioned in the midfoot in the worn shoes did indeed tend to have the highest peak midfoot pressures.

So the overall picture in the pre-super-shoe era was fairly muddy, but basically supported the view that shoes progressively lose their cushioning and reach bottom somewhere in that 300 to 500 mile range. Then came Nike’s Vaporfly in 2017, using a carbon fiber plate and a thick layer of cushioning to promise better running economy in exchange for a few hundred bucks—and, in the footnotes, less durability. The unsourced number that I frequently heard floating around after the Vaporfly’s release was that you should trust them for 100 miles or so.

It’s worth pausing here to say a few words about running shoe foams. Carlos Sánchez at RunRepeat has an impressive and exhaustive primer on the huge range of high-performance foams now on the market, which is worth digging into if you’re interested. A highly simplified history is that most running shoes used to use EVA (ethylene-vinyl acetate), then in 2013 Adidas’s Boost made TPU (thermoplastic polyurethane) popular, and then in 2017 Nike’s Vaporfly made PEBA (polyether block amide) the state-of-the-art. One study found that energy return was 66 percent for EVA, 76 percent for TPU, and 87 percent for PEBA.

While there’s been plenty of chatter about carbon-fiber plates, the weight of evidence is increasingly that most of the magic in super shoes comes from the foams. Unfortunately, the very property that makes them so good—their ethereal lightness—also makes them less durable. Of the more than three-dozen modern foams that Sánchez reviews, the main differences arise from the tweaks manufacturers make to trade off performance and longevity (along with price, of course). That makes it hard to issue general guidance about how long super shoes last: it depends on the shoe and the foam.

Still, one data point is better than zero, which brings us back to Rodrigo-Carranza’s study. The shoes he used were special prototypes manufactured for the study by On, almost identical except that one set had an EVA midsole while the other had a PEBA midsole. Both versions had a curved carbon-fiber plate. Twenty-two volunteers performed a running economy test to measure how much energy they burned at a given pace, once in fresh shoes and once in pre-worn shoes. (The researchers themselves ran exactly 280 miles in each pair of shoes to pre-wear them.)

One key finding: energy consumption in the new PEBA shoe was 1.8 percent lower than in the new EVA shoe. That bolsters the case that the foam itself is a big part of the magic, since both shoes had carbon fiber plates. (Not all PEBA foams are created equal, so we don’t know if On’s foam is as good as Nike’s ZoomX.) The other key finding: after 280 miles, there was no significant difference between the two shoes. The EVA shoe didn’t lose anything at all, whereas the PEBA shoe got 2.2 percent worse.

It’s not worth making any grand extrapolations from a single datapoint about when one type of shoe gets better than the other. Who knows what happens after 280 miles? For that matter, who knows what happened after 26 miles? Moreover, there are lots of other factors that might be relevant. One of the interesting claims in Sánchez’s review is that super foams maintain their properties even in frigid winter conditions, while EVA-based foams get much more rigid. In some shoes, firmness more than doubled after Sánchez’s freezer test. Maybe a worn-out super shoe is still a better bet than a newer EVA shoe for those of us who are latitudinally challenged. He also notes that shoe foams take more than 24 hours to recover from a run, and some recover faster than others, so it makes sense to alternate different pairs in order to maximize both comfort and shoe lifetime.

My own approach to shoe durability is, admittedly, not one that’s easy to generalize. I generally have two or three pairs on the go at any given time, and I run in them until they start to feel flat. It’s a noticeable sensation, especially if one of the other pairs in my rotation is relatively new and bouncy. Then, in the spirit of that graph above showing a plateau after about 300 miles, I keep running in them—but I pay more attention to how I feel during and after runs, and to whether the wear on the outer sole is changing the angle of my footstrike. Once I start to feel a few aches and pains, I retire the flat shoe. That approach works pretty well to keep me healthy, but the new data suggests that it’s probably not maximizing my performance. Anyone want to buy a pair of gently used six-year-old OG Vaporflys?

Some victories are measured by finish times. Others are defined by the obstacles overcome simply to reach the starting line.

For American Paralympic swimmer Ali Truwit, completing the New York City Marathon represented far more than covering 26.2 miles. It was the culmination of an extraordinary journey of survival, resilience, and unwavering determination that began with a life-altering shark attack just two years earlier.

On a crisp November morning in 2025, Truwit crossed the iconic finish line wearing a carbon-fibre running blade, fulfilling a promise she had made while recovering in a hospital bed after losing her lower left leg. The emotional milestone marked another remarkable chapter in one of the most inspiring comeback stories in modern sport.

The road to that unforgettable finish began only days after Truwit celebrated a major personal achievement. In May 2023, she completed her first marathon in Copenhagen alongside her mother. Just ten days later, while enjoying a graduation trip to Turks and Caicos with former Yale swimming teammate Sophie Pilkinton, tragedy struck.

While the pair were snorkelling, a shark attacked Truwit, severely injuring her left leg. Displaying remarkable courage, the two swam approximately 55 metres back to their boat, where Pilkinton—then a medical student—quickly applied a tourniquet that stopped the bleeding and ultimately saved Truwit's life.

Doctors were forced to amputate her lower left leg on her 23rd birthday.

Even in the darkest moments of recovery, Truwit's determination never disappeared. Reflecting on having recently completed her first marathon, she joked with one of the first responders that at least she had managed to run a marathon before the attack. The responder's simple but powerful reply would remain with her throughout rehabilitation: "You'll run another one."

Those words became a source of hope during the long and demanding road back.

Only weeks after surgery, Truwit began learning to walk on a prosthetic limb before gradually returning to the swimming pool. The process was anything but straightforward. The water that had once been her sanctuary became a source of painful memories, yet she refused to allow fear to define her future.

Her relentless work ethic soon produced extraordinary results.

Less than 16 months after the attack, Truwit represented the United States at the Paris 2024 Paralympic Games, producing a sensational performance to claim both silver and bronze medals. Standing on the Paralympic podium was a powerful reminder of how far she had come in such a short period, and she dedicated those achievements to everyone who had helped save her life.

Still, another dream remained unfinished.

The New York City Marathon carried deep personal significance. It was not merely another endurance event but a symbolic return to the city where her life had changed forever. On November 2, 2025, she lined up in Staten Island accompanied by 13 family members and close friends, all proudly representing her nonprofit foundation, Stronger Than You Think. Among them was Pilkinton, the friend whose quick thinking had preserved her life on that unforgettable day in the Caribbean.

Together, they covered every mile of the marathon before celebrating an emotional finish that Truwit later described as being "over the moon."

Completing a marathon on a carbon-fibre running blade presents challenges far beyond those faced by able-bodied runners. The prosthetic demands greater strength from the hips, core, and remaining leg while requiring exceptional balance, coordination, and endurance. Truwit's preparation combined months of disciplined training, patience, and mental resilience as she effectively taught herself how to run again.

Her story extends well beyond medals and marathon finishes.

Inspired by her own recovery, Truwit founded Stronger Than You Think, a nonprofit organisation dedicated to helping individuals overcome physical and financial barriers following limb loss. Recognising that sports prosthetics can cost tens of thousands of dollars and are often not covered by insurance, the foundation provides financial assistance for prosthetic devices, supports water-safety education, and promotes opportunities within Paralympic sport.

The organisation has already helped provide more than 11 prosthetic limbs, delivered nearly $200,000 in direct support, and funded over 4,000 hours of water-safety lessons benefiting more than 700 young people.

Throughout her journey, Truwit has remained refreshingly honest about the emotional challenges that continue to accompany recovery. She has openly acknowledged that healing is an ongoing process and that grief can still come in waves. Rather than portraying an effortless comeback, she has demonstrated that resilience is built through persistence, even on the hardest days.

Her remarkable transformation resonates far beyond elite sport. While few people will ever experience the trauma she endured, countless runners and athletes understand the frustration of injury, disappointment, or rebuilding after adversity. Truwit's journey serves as a powerful reminder that recovery is rarely linear and that courage is often measured by the willingness to keep moving forward despite uncertainty.

Now looking ahead to the Los Angeles 2028 Paralympic Games, Truwit continues to redefine what is possible. She is no longer known simply as the swimmer who survived a shark attack. She has become a Paralympic medallist, marathon finisher, advocate, and symbol of resilience whose story continues to inspire athletes around the world.

Her journey proves that while life can change in an instant, so too can the strength of the human spirit. Sometimes the greatest triumph is not returning to the person you once were, but discovering someone even stronger than you ever imagined possible.

Sprint and hurdles superstar Sydney McLaughlin-Levrone has entered an exciting new chapter in her remarkable life, welcoming her first child with husband Andre Levrone. The four-time Olympic champion and women's 400m hurdles world record holder announced the birth of their daughter, Savannah Michelle Levrone, who was born on Sunday, July 12, 2026.

The couple shared the joyful news with an emotional message celebrating the arrival of their daughter and expressing gratitude to everyone who supported them throughout the pregnancy. Sydney described Savannah as "our blessing and our joy," while expressing excitement and faith for the future that lies ahead for their growing family.

The announcement marks a deeply personal milestone for one of the most accomplished athletes of her generation. Renowned for redefining the women's 400m hurdles through a succession of record-breaking performances, McLaughlin-Levrone now embraces a new role beyond the track as a mother.

The timing of the announcement adds another layer of significance. Just days earlier, Sydney reflected on the 10th anniversary of qualifying for her first Olympic Games at only 16 years old—a breakthrough that launched one of the most decorated careers in modern athletics. Ten years later, her journey has come full circle with another life-changing milestone, underscoring that her greatest moments continue to extend beyond sporting success.

The arrival of Savannah Michelle Levrone has been met with an outpouring of congratulations from athletes, fans, and the wider sporting community, who have celebrated the couple as they begin this new chapter together. As Sydney McLaughlin-Levrone steps into motherhood, the athletics world will undoubtedly continue to follow her inspiring journey—both on and off the track.

Ethiopia's Tsige Gebreselama produced one of the standout road running performances of the season on Sunday, storming to victory at the prestigious Boilermaker Road Race 15K in Utica, New York, with a sensational course record of 47:29.

From the opening kilometers, Gebreselama controlled the race with remarkable composure and precision, maintaining a relentless pace that ultimately erased the previous course record and secured one of the fastest performances ever recorded on the historic course. Her commanding display further reinforced her reputation as one of the world's leading road and distance runners.

The Ethiopian celebration continued as Melknat Wudu crossed the finish line in second place in 47:44, completing a dominant one-two finish for her country. Kenya's Priscah Cherono claimed third in 48:14 after a determined effort, rounding out a world-class podium in a race featuring some of the finest distance runners on the international circuit.

The battle behind the podium remained fiercely competitive. Kenya's Everlyn Kemboi finished fourth in 48:28, narrowly ahead of compatriot Selah Busienei, who clocked 48:31 for fifth. Ethiopia's Netsanet Desta and Alem Nigus Tsadik followed in sixth and seventh respectively, while Kenya's Mercy Cherono secured eighth place.

American athletes also delivered encouraging performances on home roads. Veteran Stephanie Bruce finished ninth in 50:40, with Jackie Gaughan completing the top ten in 51:02 to cap a strong showing for the host nation.

Boilermaker Road Race 15K – Women's Top 10 Results

1. Tsige Gebreselama (Ethiopia) – 47:29 (Course Record)

2. Melknat Wudu (Ethiopia) – 47:44

3. Priscah Cherono (Kenya) – 48:14

4. Everlyn Kemboi (Kenya) – 48:28

5. Selah Busienei (Kenya) – 48:31

6. Netsanet Desta (Ethiopia) – 48:46

7. Alem Nigus Tsadik (Ethiopia) – 48:48

8. Mercy Cherono (Kenya) – 50:23

9. Stephanie Bruce (United States) – 50:40

10. Jackie Gaughan (United States) – 51:02

The women's race combined exceptional depth with remarkable speed, as several athletes broke the 49-minute barrier in a contest that showcased the global strength of elite road running. Gebreselama's record-breaking run now stands as a new benchmark in the rich history of the Boilermaker 15K, adding another memorable chapter to one of the United States' most celebrated road races.

Kenya's Alex Matata delivered a sensational performance to claim the men's title at the prestigious Boilermaker Road Race 15K in Utica, New York, producing a dominant run that underlined his growing reputation as one of the world's finest road racers.

Matata surged to victory in an outstanding time of 42:24, mastering the demanding course with a display of strength, speed, and tactical brilliance. His commanding performance secured a memorable triumph in one of the United States' most celebrated road races, adding another significant international victory to his career.

Kenya's success was further highlighted by Kiprono Sitonik, who produced an equally impressive run to finish second in 42:53, completing a remarkable one-two finish for the East African nation. South Africa's Adam Lipschitz rounded out the podium after clocking 43:14 to claim third place following a determined effort.

The race featured a highly competitive international field, with American athletes Reid Buchanan and Hillary Bor finishing fourth and fifth respectively, while another Kenyan, Victor Shitsama, added to his country's strong showing by taking sixth place.

Matata's victory once again showcased Kenya's enduring strength in global road racing, as its athletes continued to dominate major international competitions through exceptional endurance, tactical awareness, and relentless finishing speed. His performance in Utica not only thrilled the spectators lining the streets but also reinforced the depth of Kenyan distance running on the world stage.

Men's Top 10 Results – Boilermaker Road Race 15K

1. Alex Matata (Kenya) – 42:24

2. Kiprono Sitonik (Kenya) – 42:53

3. Adam Lipschitz (South Africa) – 43:14

4. Reid Buchanan (United States) – 43:38

5. Hillary Bor (United States) – 43:40

6. Victor Shitsama (Kenya) – 44:02

7. Futsum Zienasellassie (United States) – 44:32

8. Charlie Sweeney (United States) – 44:37

9. Sam Lawler (United States) – 44:54

10. Tyler Berg (United States) – 45:08

With another major road racing title added to his résumé, Alex Matata continued his impressive 2026 campaign while reinforcing his status as one of the leading names on the international road racing circuit. The Boilermaker 15K once again delivered a high-quality contest, with athletes from across the globe producing memorable performances in one of the United States' most prestigious road races.

Eliud Kipchoge's remarkable World Tour continued on Brazilian soil as the Kenyan marathon icon completed the New Balance 42K Porto Alegre Marathon, crossing the finish line in 2:18:39 to place 12th overall during the second stop of his ambitious seven-continent global running tour.

Competing against a strong international field, the two-time Olympic marathon champion displayed the resilience and determination that have defined his legendary career. While the result was not among the victories that have made him one of the greatest marathon runners in history, Kipchoge once again demonstrated the unwavering commitment that continues to inspire athletes and fans across the globe.

Morocco's Zineddine Ouria claimed victory in a superb 2:08:49, with Kipchoge finishing 9 minutes and 50 seconds behind the race winner after navigating the demanding course in Porto Alegre.

Kipchoge began the race with controlled and confident pacing, reaching 5km in 15:34 before passing the halfway mark in 1:05:07. As the race entered its decisive stages, the pace gradually slowed, but the veteran marathoner pressed on with characteristic determination, completing the 42.195-kilometre challenge in 2:18:39.

For many, the story will be told through the finishing position. But for those who truly understand greatness, this journey is about far more than medals, records, or podium finishes. Kipchoge's World Tour is a celebration of the sport itself—an opportunity to connect with runners across every continent, inspire the next generation, and continue living by the philosophy that has become synonymous with his career: "No Human Is Limited."

The Brazilian appearance also carried added significance, coming shortly after Kipchoge was permanently honoured in Porto Alegre with his footprints unveiled at the entrance of Parque Harmonia—a lasting tribute to his extraordinary impact on distance running and his enduring legacy in the sport.

Once a champion. Forever an inspiration. Legends do not stop inspiring when the victories become fewer; they inspire because they never stop showing up. Through every stride, every finish line, and every challenge embraced, Kipchoge continues to prove that true greatness is measured not only by what an athlete wins, but by the lives they touch along the way.

With the second stop of his World Tour now complete, Kipchoge will turn his attention to the next chapter of his global adventure when he lines up at the Melbourne Marathon in Australia this October. Wherever he races, millions will once again follow the journey of a man whose legacy extends far beyond the stopwatch.