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?

Jakob Ingebrigtsen brought his remarkable 2026 season to a fitting close on home soil, winning the men’s street 1500m at the inaugural Runfest Norway in Sandnes on Friday.

Competing in front of an enthusiastic hometown crowd, the Olympic and world champion took control of the race from the early stages and maintained his authority through the finish, stopping the clock at 3:40.7.

Andreas Fjeld Halvorsen followed in second in 3:43.3, while Sigurd Tveit completed the podium in 3:47.8.

The unusual street race added another dimension to the occasion, with 273 runners taking part on the same road and sharing the course with one of Norway’s most accomplished distance runners. For the recreational participants, it offered a rare opportunity to compete alongside Ingebrigtsen in an event that brought elite athletics and mass participation together.

The victory also provided a fitting final chapter to a season that began with significant uncertainty for Ingebrigtsen. After undergoing major Achilles surgery in February, the Norwegian was forced to miss a substantial portion of the summer campaign as he worked his way back to full fitness.

His return, however, quickly developed into another championship-winning chapter. In Birmingham, Ingebrigtsen captured European 5,000m gold before adding another major title at the inaugural World Athletics Ultimate Championship in Budapest, where he won the 5,000m.

Those performances transformed what could have been a disrupted season into another year defined by championship success and a determined return to the highest level.

Now, with the Sandnes victory added to his 2026 record, Ingebrigtsen closes the year exactly where it began in spirit — overcoming adversity, rebuilding his form and once again competing at the front.

From Achilles surgery in February to major championship victories and finally a 1500m win before his hometown crowd, the Norwegian has given his 2026 season a memorable final scene.

Olympic 100m hurdles champion Masai Russell has announced her engagement to longtime partner Robert “Robbie” Springfield, adding a major personal milestone to the remarkable journey of one of America’s leading track and field stars.

Russell shared the news with her followers, revealing that Springfield had proposed and that she had accepted. Reflecting on their relationship, the Olympic champion described him as her best friend and expressed her excitement about spending the rest of her life with him.

The couple’s relationship dates back to their college years at the University of Kentucky, where both were student-athletes and competed in track and field. Russell established herself as a standout hurdler, while Springfield competed in the long jump, giving them a shared understanding of the demands, sacrifices and pressures that come with pursuing success in athletics.

Springfield has since transitioned from competition into coaching. A former collegiate long jumper, he is now part of the coaching staff at Morehead State University, where he works with the programme’s sprinters and jumpers.

Their relationship has developed alongside Russell’s rise to the top of the sport. The defining moment of her career came at the Paris 2024 Olympic Games, where she captured gold in the women’s 100m hurdles, securing her place among the sport’s Olympic champions.

Away from competition, Springfield has remained a familiar part of Russell’s journey, sharing in the demanding periods of training and competition that accompanied her pursuit of Olympic success. Their connection has consequently grown from a college athletics relationship into a long-term partnership.

The engagement now marks another significant chapter for Russell, this time away from the track. After reaching the pinnacle of her sporting career in Paris, the 100m hurdles champion is beginning a new phase of her personal life alongside a partner who has been part of her journey since their university days.

From competing on the same collegiate stage to building a future together, Russell and Springfield’s story has evolved alongside two careers shaped by track and field. The Olympic champion will now balance this new personal chapter with her continuing ambitions in athletics

The women’s race at the 2026 TCS Amsterdam Marathon is shaping up to be one of the most competitive editions in recent years, with a deep international field set to take on the fast Dutch course on Sunday, October 18.

At the centre of the contest will be four Ethiopian athletes who have already broken the 2:20 barrier, creating the prospect of a fascinating battle for victory and a possible assault on the course record of 2:16:52.

Defending champion Aynalem Desta will return to Amsterdam looking to retain her title after producing the biggest performance of her career at last year’s 50th edition. Desta won in a personal best of 2:17:37, establishing herself among the leading marathoners in the field and setting the benchmark for this year’s contenders.

Standing in her way will be fellow Ethiopian Meseret Belete Tola, a former Amsterdam champion who knows exactly what it takes to succeed on the course. Belete Tola captured the 2023 edition in 2:18:21, and her return adds another layer of experience and proven quality to an already formidable lineup.

The field also includes Mestawut Fikir Truneh, who arrives with an impressive marathon pedigree. Truneh finished runner-up at the 2024 Berlin Marathon in 2:18:48, demonstrating her ability to compete at the highest level on one of the world's major marathon stages.

Completing the quartet of sub-2:20 Ethiopians is Buze Diriba, whose personal best of 2:19:34 places her firmly among the leading contenders. With four athletes possessing credentials below 2:20, the race is likely to develop into a tightly contested battle from the opening kilometres.

The depth extends well beyond the leading quartet. Desi Jisa Mokonin, representing Bahrain, Yeshi Kalayu Chekole of Ethiopia and Nazret Weldu Gebrehiwet of Eritrea have all established themselves as serious marathon competitors with performances approaching the 2:20 mark.

Another major name to watch is Abeba Aregawi, the former 1500m world champion representing Sweden. Aregawi has successfully transferred her talents to the marathon and made headlines earlier this year by setting a Swedish national record of 2:23:12 on her debut. Her presence adds another intriguing dimension to an already high-quality field.

Amsterdam’s marathon course has consistently provided an opportunity for elite athletes to produce fast times, and this year’s women’s lineup has the depth to turn the race into a genuine test of both championship racing and outright speed.

With four athletes already inside 2:20, two former Amsterdam champions returning to the start line and several other accomplished marathoners ready to challenge them, the battle is expected to remain open deep into the race.

The ultimate target will be the Amsterdam women’s course record of 2:16:52. Whether the leading contenders can threaten that mark remains to be seen, but the quality assembled for October 18 ensures that the record will be firmly in the spotlight when the race reaches its spectacular finish inside the Olympic Stadium.

The 2026 Valencia Half Marathon is shaping up to be a thrilling contest of speed, endurance and tactical brilliance, with some of the world’s finest road runners set to converge in Spain on October 25.

Kenya’s Daniel Ebenyo and Alex Matata will be among the leading contenders, facing a formidable Ethiopian challenge spearheaded by Jemal Yimer and Tadese Worku. The field also features Rodrigue Kwizera, who boasts the fastest personal best among the leading entrants at 58:16.

Ebenyo arrives with a personal best of 59:04, placing him firmly among the athletes capable of sustaining a demanding pace over the 21.1-kilometre distance. Matata, who owns a 59:11 best, adds further Kenyan strength, while Andrea Kiptoo brings another sub-60-minute credential to the race.

Yimer has already established himself as one of the fastest athletes in the field with a 58:33 personal best, while Worku has clocked 58:35. Kenya’s Owen Korir, with a best of 58:58, further underlines the remarkable depth of the men's lineup.

Valencia Half Marathon 2026 Entries

1. Rodrigue Kwizera (Spain) — 58:16

2. Jemal Yimer (Ethiopia) — 58:33

3. Tadese Worku (Ethiopia) — 58:35

4. Owen Korir (Kenya) — 58:58

5. Daniel Ebenyo (Kenya) — 59:04

6. Alex Matata (Kenya) — 59:11

7. Andrea Kiptoo (Kenya) — 59:11

8. Thierry Ndikumwenayo (Spain) — 59:42

9. Said Mechaal (Spain) — 1:00:24

10. Adel Mechaal (Spain) — 1:02:30

Kwizera, who finished second in Valencia last year, leads the field on paper and will be seeking another standout performance on the famously fast Valencia course. With several athletes carrying sub-60-minute credentials, the race has the ingredients for an aggressive battle from the opening kilometres.

Beyond the headline names, the men’s field is deep and highly competitive, bringing together a strong collection of experienced international athletes with proven ability over the half-marathon distance. With so much quality packed into the lineup, the race promises an intriguing battle in which tactics, endurance, positioning and finishing speed could all play a crucial role in determining the eventual champion.

Yet personal bests will count for little once the gun goes off. The title could ultimately be decided by patience, positioning and the ability to respond when the pace begins to rise in the closing stages. Every surge, every tactical move and every second saved could prove decisive on the road to the finish.

With Kenya, Ethiopia and Spain represented by athletes of exceptional quality, Valencia promises a high-octane men's showdown in which the leaders are likely to be separated by only a handful of seconds. The final kilometres could provide the defining moments of a race packed with speed, ambition and anticipation.

On October 25, the question will be simple: who has the strength to command the streets of Valencia and claim the coveted half-marathon crown?

April 19, 1982. The Boston Marathon unfolded under unusually warm, sunny conditions, and by the closing stages, the race had become a private battle between two very different American runners: Alberto Salazar, already one of the biggest names in distance running, and Dick Beardsley, the Minnesota runner who had emerged as a serious marathon contender.

For roughly nine miles, from the Newton Hills toward the finish, Beardsley did much of the leading, with Salazar tucked close behind. Neither man could shake the other. They ran deep into Boston locked together, trading surges and refusing to surrender an inch as the crowds along the course grew louder.

Salazar finally made his decisive move with less than a mile remaining. He opened a small gap, but Beardsley refused to disappear. The Minnesota runner chased him through the final streets, closing again as they approached the finish.

Then came the final sprint.

Salazar held his form and reached the finish first in 2:08:52, with Beardsley only two seconds behind in 2:08:54. It was an extraordinary result: both men broke 2:09 in the same Boston Marathon, and both shattered the previous course record.

The race became known as the “Duel in the Sun,” and it remains one of the most celebrated head-to-head battles in Boston Marathon history. Beardsley had not won, but his performance established him as one of America's elite marathoners.

For Salazar, however, victory came at an enormous physical cost. Immediately after crossing the finish line, he collapsed and required emergency treatment, including several litres of intravenous saline. The combination of heat, dehydration and an all-out effort had pushed his body to the limit.

Salazar's marathon career would never again produce quite the same kind of performance. His celebrated 1981 New York City Marathon victory had produced what was initially considered a world record, although the course was later found to be short. His Boston triumph therefore became one of the defining victories of his career.

Beardsley's story would take an even more difficult turn. Injuries disrupted his career, and after returning to the highest level, he suffered a devastating farm accident in 1989. Further accidents, surgeries and severe physical pain followed, eventually leading to a long battle with painkiller addiction.

He eventually overcame that struggle and transformed the darkest chapters of his life into a story of recovery, resilience and redemption.

That is what makes the 1982 Boston Marathon more than a two-second victory.

For one extraordinary afternoon, Salazar and Beardsley produced a marathon duel in which neither man was willing to give way. One crossed the finish line first. The other finished only two seconds behind him.

Two seconds separated them at Boston. Decades later, their legendary duel remains one of the greatest chapters in marathon history.