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Contrary to what scientists once thought, even superficial cooling is enough to interfere with muscle oxygen supply.

The human body is an engine with efficiency similar to a car engine. In both cases, about three-quarters of the energy consumed is released as heat. That’s why it’s easy to heat the interior of a car: just blow some of that heat from the engine into the cabin. And it’s why endurance athletes worry a lot about getting too hot but mostly view cold as a minor annoyance rather than a fundamental limit on performance. If you’re pushing hard enough, you won’t be cold for long—right?

But new research published in the Journal of Applied Physiology suggests that cold really does diminish endurance performance. That’s contrary to what some previous research has found, but those earlier studies often involved volunteers who were ushered into a cold room and then immediately asked to exercise without waiting for their body temperatures to drop. In the new study, the volunteers got cold—and then stayed cold, no matter how hard they exercised. That’s a lesson that winter athletes will want to keep in mind next time they’re lingering in frosty air before a workout or a race.

The study was led by Phillip Wallace as part of his doctoral work in Stephen Cheung’s Environmental Ergonomics Laboratory at Brock University in Canada. Cheung is a serious cyclist whose lab has produced a bunch of interesting endurance-related research that I’ve written about previously on topics like heat, hydration, and self-talk. Cold research, on the other hand, usually focuses on safety-related topics like hypothermia and frostbite.

The new study compared cycling performance in four different conditions. In the control “thermoneutral” condition, the subjects sat in a temperature-controlled chamber set at 72 degrees Fahrenheit (22 Celsius) for 30 minutes. Then they started cycling with five minutes of warm-up at 100 watts before pedaling to exhaustion at 70 percent of VO2 max, which took on average just under 24 minutes. In the “cold shell” condition, the chamber was set to 32 degrees Fahrenheit (0 Celsius) and a wind speed of about one meter per second was added. Half an hour in these conditions was enough to significantly decrease skin temperature without dropping core temperature (as measured with a rectal thermometer) before starting the cycling test.

For the other two conditions, the subjects—ten men with an average age of 27—stayed in the 32-degree Fahrenheit chamber for long enough to drop their core temperatures by 0.9 or 1.8 degrees Fahrenheit (0.5 or 1.0 Celsius) before cycling, imposing mild hypothermia. Because of differences in body size, shape, and composition, people cool at different rates, but on average it took 116 minutes to reach the first threshold. For the second threshold, the average was 160 minutes, though three of the subjects didn’t cool all the way before hitting the maximum cooling time imposed by the research ethics board. During all the cooling trials, the subjects wore a T-shirt or cycling jersey and cycling shorts plus earmuffs, winter gloves, and a fleece blanket around their shoes—added warmth that turned out to be necessary during pilot testing.

There are a bunch of reasons you might expect endurance to suffer in the cold. Even with just a cold shell, your peripheral blood vessels will constrict, decreasing the flow of oxygen to your muscles. Cold also has more subtle effects on the chemistry of how oxygen is transported in the blood. And once you start shivering, you can burn a substantial amount of energy: in this study, the metabolic heat generated by the subjects doubled from the equivalent of about 10 percent of VO2 max in the thermoneutral condition to 20 percent in the hypothermic conditions. Shivering can also interfere with muscle contraction and coordination, and may even fatigue the muscles themselves.

Despite all these negatives, previous studies with similar cycling tests at 70 percent of VO2 max found that performance in 37 to 39 degrees Fahrenheit was either unaffected or even improved compared to moderate temperatures. Wallace’s results with pre-cooling were dramatically different, though. Time to exhaustion on the bike dropped from 23.8 to 16.2 minutes in the cold shell condition, 8.5 minutes in the first hypothermia condition, and 6.5 minutes in the second one. The results provide clear evidence that skin cooling alone is enough to reduce endurance by about 30 percent, and core cooling takes away another 30 to 40 percent.

It’s interesting to look at how the core temperatures evolved over the course of the time trials. Here’s a graph showing changes in temperature for thermoneutral (TN), cold shell (CS), and the two hypothermia (HYP) trials:

For both thermoneutral and cold shell, core temperature rises steadily through the time trial, as you expect from running a heat-generating engine to its limits. For the two hypothermia trials, on the other hand, the curve is almost flat, even though they’re cycling at exactly the same power output in all four trials. In fact, the core temperature even decreases during the first quarter of the trial, perhaps because warm blood is being pumped to peripheral muscles and cold blood is being shunted back to the core. The nuances of how heat is stored and moved around within the body are complex, but the upshot is that even cycling to exhaustion isn’t enough to warm you up if you’ve lingered for long enough in temperatures around the freezing mark.

One variable that’s hard to control is the mental effects of sitting around in a cold chamber for several hours. Physiology aside, you have to imagine that in those trials, the subjects just wanted to go home rather than ride a bike. As expected, their pre-ride motivation was lower, dropping from an average of three on a four-point scale in the thermoneutral trial to 2.5 and 2 in the hypothermia trials. Their initial perception of exertion when they started riding was also higher: 12 and 12.5 rather than 9.5 on the Borg scale, which measures exertion on a scale from 6 to 20. But by the end of the ride, the riders hit a max of 20 in all four conditions—so it’s not like they were unable or unwilling to push themselves.

The revelation that being really cold is bad for endurance may not seem that surprising. The most interesting distinction here, I think, is between exercising in the cold and being cold before you start exercising. One of my pathological neuroses as a runner is the fear of hearing the starting gun fire while I’m still wrestling to get my sweatpants off over my racing shoes. As a result, I often strip off my warm-ups well before the start even in sub-freezing temperatures. If there’s one idea I’ll take away from Wallace’s research, it’s that I need to invest in some tearaway pants.

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.