Running News Daily is edited by Bob Anderson and team. Send your news items to bob@mybestruns.com Advertising opportunities available.
Index to Daily Posts · Sign Up For Updates · Run The World Feed
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.
Login to leave a comment
The future of American distance running may have just announced itself.
Luke Surface, an 8th-grade student-athlete from North Raleigh Christian Academy in Raleigh, North Carolina, delivered a performance that stunned the track and field community after taking on some of the nation’s best high school runners at Nike Outdoor Nationals.
Competing at the legendary Hayward Field in Eugene, Oregon — one of the most iconic venues in American distance running — Surface lined up in the boys championship 5,000 meters against a field dominated by high school seniors, including several athletes preparing to compete at the NCAA Division I level.
Despite being one of the youngest runners in the race, the 14-year-old held his own against the elite competition, finishing eighth in an incredible 14:25.88. The performance set a new national middle school record, averaging approximately 4:39 per mile for more than three miles.
That kind of time is fast enough to win many high school state championships across the United States and meets qualifying standards for several major NCAA Division I conference competitions — a remarkable achievement for a runner who has not yet entered high school.
But Surface’s historic 5,000m performance was only the latest chapter in a season filled with record-breaking moments.
Earlier in May, he clocked 8:52.03 for 3,200 meters at the NCISAA Division I State Championships in North Carolina, breaking another national middle school record. His converted two-mile time of 8:55.12 surpassed the previous world-best mark for a 14-year-old age group, previously held by Vincent Recupero.
During the previous cross-country season, Surface also made headlines when he ran 15:12 at the adidas XC Challenge, finishing second while competing against runners who were several years older.
Across cross country, two miles, and the 5,000 meters, Surface has continued to prove that his talent is far beyond his age group. While he still has four years of high school competition ahead before reaching the college level, his performances have already placed him among the most exciting young distance runners to watch.
The American high school 5,000-meter record currently stands at 13:32, set by Lex Young in 2023 — a mark Surface is not yet close to challenging. However, his remarkable progression at such a young age has caught the attention of the running world, with many eager to follow how far his extraordinary journey can go.
For now, Luke Surface remains an eighth grader rewriting the record books — and his story is only beginning.
Login to leave a comment
DOHA, Qatar – Ethiopian distance running is once again making a powerful statement on the global stage. Following the Doha Diamond League meeting, Ethiopia has achieved a remarkable clean sweep of the women's 3000m/5000m standings, occupying all eight leading positions in one of the most competitive disciplines in world athletics.
Leading the charge is Likina Amebaw, who sits comfortably at the top of the rankings with 22 points. Close behind is fellow Ethiopian star Freweyni Hailu on 14 points, while Medina Eisa occupies third place with 12 points. The dominance continues through the rest of the leaderboard, with Senayet Getachew, Hawi Abera, Aleshign Baweke, Marta Alemayo, and Bernesh Dessie completing an extraordinary Ethiopian monopoly of the standings.
The achievement highlights Ethiopia's exceptional depth in women's distance running, where a new generation of athletes continues to emerge and challenge for global honours. Rather than relying on a single standout performer, Ethiopia has assembled a formidable squad capable of controlling races and collecting points across multiple Diamond League meetings.
While the current standings paint a picture of complete Ethiopian supremacy, the battle for the Diamond League title is far from over. Several meetings remain on the road to the season finale, leaving plenty of opportunities for rivals to close the gap and for positions within the Ethiopian contingent to shift dramatically.
For now, however, the spotlight belongs firmly to Ethiopia. The East African powerhouse has transformed the women's 3000m/5000m standings into an all-Ethiopian affair, sending a clear message to the rest of the world that the race for Diamond League glory will likely run through Addis Ababa.
The question now is whether Likina Amebaw can maintain her advantage and finish the season as the overall leader, whether Freweyni Hailu or Medina Eisa can mount a successful challenge, or whether another athlete will produce a late-season surge to rewrite the script.
One thing is certain: the road to the Diamond League Final promises a fascinating battle among some of the finest distance runners on the planet.
Login to leave a comment
Kenyan athletics superstar and world champion Beatrice Chebet has officially entered a beautiful new chapter in her life after welcoming a baby boy.
The 26-year-old track sensation, born on 5 March 2000, has built a remarkable legacy as one of the greatest distance runners of her generation. Chebet is a world record holder in the 5000m, 10,000m and road 5km, with a career decorated by historic victories on the biggest stages.
She made history at the 2024 Summer Olympics by winning gold medals in both the 5000m and 10,000m, before achieving the same remarkable double at the 2025 World Athletics Championships. Her medal collection also includes a 5000m silver medal at the 2022 World Athletics Championships and bronze at the 2023 World Athletics Championships.
Beyond the track, Chebet has also dominated cross country, becoming a three-time world champion after winning the junior title in 2019 and senior titles in 2023 and 2024. She has also claimed major 5000m victories at the 2018 World U20 Championships, 2022 Commonwealth Games and the 2022 African Championships in Athletics.
Now, the Kenyan star is celebrating a different kind of milestone — becoming a mother.
Sharing the joyful news, Chebet introduced her newborn son with a heartfelt message filled with love and excitement:
“Tiny hands, tiny feet, and a love so big! A beautiful new chapter begins. Welcome to our world our sweet little baby boy!”
The arrival of her son marks a special moment away from competition, as the world champion embraces motherhood while carrying the pride of a nation that has watched her achieve greatness.
Messages of congratulations have poured in from fans and the athletics community, celebrating the new chapter for one of Kenya’s most successful athletes.
As Beatrice Chebet adds motherhood to her list of remarkable achievements, the champion now begins a new journey filled with love, joy, and unforgettable moments with her baby boy.
Login to leave a comment
Jake Wightman delivered a masterclass in championship racing as he surged to the men's 800m title at the UK Athletics Championships, holding off a determined challenge from Ben Pattison in a thrilling finish.
In a race defined by patience, positioning, and precise execution, Wightman waited for the perfect moment to strike before unleashing his finishing kick down the home straight. The former world champion crossed the line in 1:45.40, just doing enough to edge Pattison and secure the national crown.
The contest lived up to expectations, bringing together two of Britain's finest middle-distance talents in a tactical battle where every move carried significance. With the pace controlled through the early stages, the field remained tightly packed, setting the stage for a dramatic final lap.
As the bell rang, the intensity immediately rose. Pattison looked poised to seize control and pushed hard in the closing metres, but Wightman's experience and race awareness proved decisive. Drawing on years of competing at the highest level, he maintained his composure under pressure and found the extra gear required to stay ahead when it mattered most.
The victory marks another significant chapter in Wightman's decorated career and serves as a timely statement of intent as the international season gathers momentum. More importantly, it showcased the qualities that have made him one of Britain's most respected middle-distance athletes — tactical intelligence, resilience, and an ability to deliver in the biggest moments.
For Pattison, the narrow defeat will provide encouragement rather than disappointment. His performance confirmed his growing status among Britain's elite 800m runners and highlighted the depth of talent currently thriving in the event.
But on this occasion, the spotlight belonged to Wightman. In a race where the margins were razor-thin, he executed his plan to perfection and walked away with the UK Athletics Championship title.
Login to leave a comment
Remember the name Gout Gout.
At just 18 years old, the Australian sprint prodigy is already commanding global attention and fueling conversations about the future of track and field. In a sport constantly searching for its next superstar, Gout is rapidly emerging as one of the brightest talents the world has seen in years.
His latest statement came at the prestigious Ostrava Golden Spike meeting, where he stepped onto the track alongside some of sprinting's biggest names, including reigning world champion Noah Lyles. Far from being overwhelmed by the occasion, the teenager delivered a composed and confident performance, finishing third in the 150m in 14.96 seconds against two of the fastest athletes on the planet.
Yet impressive as that performance was, it is not the result that has the athletics community buzzing most.
Earlier this year, Gout stunned the sprinting world by clocking an astonishing 19.67 seconds for 200m, setting a new world Under-20 record. The performance instantly elevated him from promising prospect to genuine phenomenon.
What makes the achievement even more remarkable is the historical context. At the same age, Gout was faster than sprint legend Usain Bolt. Comparisons to the Jamaican icon are inevitable, not because records demand them, but because the raw numbers are impossible to ignore.
Of course, Gout's journey is only beginning. Like any young athlete, he still has room to grow, refine his craft, and gain valuable experience at the highest level. The road from teenage sensation to global champion is rarely straightforward.
But there is no denying the extraordinary potential that lies within him.
His speed, composure, and ability to perform under pressure have already marked him out as one of athletics' most exciting young stars. More importantly, he possesses the kind of talent that inspires belief that a new era of sprinting may be on the horizon.
The sport has always thrived on rivalries that capture the imagination of fans across the globe. With established champions such as Noah Lyles currently leading the way, the emergence of Gout Gout adds an intriguing new chapter to sprinting's future.
The next great rivalry may already be taking shape.
And one of its leading figures is still only a teenager.
For now, the message is simple: remember the name Gout Gout. The future is arriving faster than anyone expected.
Login to leave a comment