Running News Daily

I used to think running was a panacea. "If the furnace is hot enough, anything will burn, even Big Macs," as the fictional miler Quenton Cassidy once said. Then, about a decade ago, there was a big surge of doubt about the health effects of running. Most prominent was the suggestion that even modest amounts of running might damage your heart-"One Running Shoe in the Grave," as the Wall Street Journal put it-but running was also accused of broader sins like promoting inflammation, causing muscle loss, and wreaking havoc on blood sugar levels.

As a runner and a journalist, I spent a lot of time trying to understand these claims, and reevaluating my own understanding of running's health effects-a process that continues to this day. Part of that process involved going back to the original research that led us to believe that running is healthy. And to be honest, the evidence wasn't as clear as I'd assumed. Does running (or aerobic exercise more generally) really improve health markers, or is it just that healthy people are more likely to choose to run? Do the benefits max out after a few minutes per day, or do they keep growing? Can you outrun a bad diet?

I have opinions about all these questions, but I no longer assume that the answers are obvious. So I'm always interested in new data, like a recent study in PLoS ONE from the science team at InsideTracker, a company that sells personalized blood testing to track various health biomarkers. The paper offers a peek at the aggregated results of more than 23,000 customers who report various levels of running, divided into three groups: low volume (less than three hours of running per week), medium volume (three to ten hours per week), and high volume (more than ten hours per week). For comparison, they also include results from 4,400 sedentary non-runners, and at the opposite end of the spectrum, 82 professional distance runners.

There are two important caveats to point out before diving into the data. First, this is observational data, not a randomized trial. That makes it hard to determine whether running causes any of the patterns in the data (though, as we'll see below, there are some ways to test our assumptions about causation). Second, this is a self-selected cohort. Even the sedentary group is made up of people who are interested enough in their health that they've decided to spring for a service that starts at $699 for a single battery of blood tests. Since this control group is already fairly healthy, detecting any improvements will be more challenging.

The Raw Data

The journal article (which is free to read online) presents data on 27 different biomarkers that were significantly different between runners and non-runners. I'm just going to pick out a few categories that are particularly interesting.

First, here's HDL (i.e. "good") cholesterol levels, for females (f) and males (m) in each of the five groups: pro runners, high-, medium-, and low-volume amateurs (HVAM, MVAM, and LVAM, respectively), and sedentary people.

The biggest difference is between runners and non-runners: runners have clearly higher levels, which is good. And among the runners, the trend is that more running is associated with higher levels. Similar patterns are seen for LDL ("bad") cholesterol and triglycerides: running is good, and more running is better.

The pattern here is much less pronounced. There's still a significant difference between runners and non-runners, but the dose-response effect of more mileage is smaller in men and non-existent for women. The same is true when looking at HgbA1c levels, which offer an estimate of long-term average blood sugar levels rather than a single snapshot. In that case, there's a more pronounced difference between runners and non-runners, but no dose-response response effect. For blood sugar, then, running is good but more running isn't necessarily better.

One key point: the sedentary control group has remarkably good blood sugar levels, with an average below the prediabetes cutoff. Given that 98 million Americans have prediabetes, this confirms that the control group is already pretty healthy. If you were to compare runners to the average population, you'd probably see a bigger effect.

Another group of biomarkers is associated with chronic low-grade inflammation. The pattern here is a little more complicated, but data on C-reactive protein, white blood cell count, and ferritin collectively suggest that greater volumes of running are associated with lower levels of inflammation. The fact that ferritin is considered a marker of inflammation was a surprise to me, since I think of it as an indicator of iron levels in endurance athletes. But it turns out ferritin levels can mean different things in different contexts.

For most of the biomarkers, there's a fairly smooth trend from sedentary to pro runners. But there are a few examples where the pro runners are noticeably different from everyone else, even the amateurs who claim they're running more than ten hours a week. Most notably, the pro runners tended to have low magnesium levels-an observation that mirrors earlier data from British Olympic track athletes. The British study also found that athletes with a history of tendon problems were most likely to have low magnesium levels, which suggests that it's something to watch for if you're training hard.

Is It All About BMI?

All the results I mentioned above were statistically adjusted for body-mass index, age, and sex. That's important, because there were significant differences in BMI among the groups. Here's that data:

Now, I look at this graph and think, "Yep, all else being equal, the more you run the less you weigh." This used to strike me as a painfully obvious statement. The current scientific consensus, on the other hand, is that exercise is ineffective for weight loss. And it's true that lots of studies have assigned people to exercise, sometimes quite vigorously, and have seen underwhelming results for weight loss. This is a complex topic whose nuances I'll leave for another day, but suffice to say that the new data agrees with my feeling that, if you're running more than an hour a day, you very likely weigh less than you would if you weren't running.

You can get another level of insight by adding in some of the genetic data that InsideTracker also collects from some of its customers. There are a large number of separate gene variants that are associated with higher BMI; by checking which of these variants a given individual has, the researchers calculated a "polygenic risk score" for obesity. In the sedentary group, those with higher risk scores tended to have higher BMI. Among the high-volume and pro runners, in contrast, that trend was flattened: those with higher risk scores had similar BMI to those with lower scores. Though the sample size was too small to draw definitive conclusions (since relatively few customers opted to get genetic testing), the results suggest that running counteracted the gene variants associated with obesity.

The BMI data raises another important question: are all the other apparent health benefits of running just secondary effects of lower BMI? Here they use a cool technique called Mendelian randomization (which I wrote about in another context earlier this year). It's a way of turning a large observational study into a randomized trial. The randomization occurs at birth: as noted above, some people have gene variants that predispose them to have a higher BMI. These variants are randomly distributed, so if people with the low-BMI versions tend to also have better cholesterol scores (for example) regardless of whether or not they run, it suggests that BMI is what's driving the cholesterol scores.

The results of the Mendelian randomization-again limited by low sample numbers-are somewhere in the middle. It does appear that BMI explains much of the group's difference in cholesterol and inflammation levels, for example-but not all of it. For example, gene variants didn't predict LDL levels, suggesting that it's an independent effect of running.

But the closer you look, the blurrier the line between genes and behavior gets. Some of the genes associated with exercise are also associated with motivation and self-control; people who exercise a lot are also more highly motivated to eat healthily; and so on. We're back to the challenge I mentioned at the top: teasing out the independent health effects of going for a run is really hard. The InsideTracker researchers conclude that "a holistic wellness lifestyle approach is in practice the most likely to be most effective toward preventing cardiometabolic disease." That borders on tautological, but their data adds another small brick to the pile of evidence suggesting that endurance exercise, even or perhaps especially in large quantities, is a useful part of that holistic wellness lifestyle.

Melissa Jefferson-Wooden delivered a sensational performance in Budapest, storming to victory in the women’s 100m at the inaugural World Athletics Ultimate Championship in a breathtaking 10.62 seconds.

The American produced a superb display of acceleration and composure to claim the World Ultimate Championship title while recording the fastest women’s 100m time in the world this year. Her 10.62 mark underlined her exceptional form and placed her firmly at the top of the global sprinting hierarchy.

Jefferson-Wooden controlled the race through the decisive stages and maintained her form all the way to the finish to secure a statement victory against a field packed with championship pedigree. She crossed the line ahead of Olympic champion Julien Alfred, who clocked 10.74 seconds with a -0.2 m/s wind, while Sha’Carri Richardson took third in 10.76.

Women’s 100m Final

1. Melissa Jefferson-Wooden — 10.62

2. Julien Alfred — 10.74 (-0.2 m/s)

3. Sha’Carri Richardson — 10.76

The victory was especially significant given the quality of the opposition. Jefferson-Wooden held her nerve against Alfred and Richardson, two of the most accomplished sprinters of the current generation, to produce the fastest performance in the world this year when it mattered most.

Alfred once again demonstrated her consistency at the highest level by taking silver, while Richardson completed an all-star podium in a race that brought together three of the biggest names in women’s sprinting.

But beyond the time, the title and the celebration, one of the most touching moments came after the race when Jefferson-Wooden embraced her father, Melvin, in an emotional celebration.

Their moment carried a deeply personal meaning. When Melissa was just 17 years old, she donated her stem cells to help her father undergo a bone marrow transplant after he was diagnosed with myelodysplastic syndrome. Years later, the two shared an unforgettable embrace in Budapest after she had become the World Ultimate Champion.

For Jefferson-Wooden, however, the evening was about far more than a medal. It was the culmination of an extraordinary journey, now highlighted by a world-leading 10.62 seconds on one of the biggest stages in athletics.

With the Ultimate Championship title secured and her father by her side, Jefferson-Wooden leaves Budapest with more than being an ultimate champion. She leaves with momentum, confidence and a powerful statement of intent — turning a high-profile showdown into one of the defining sprint performances of her season.

Audrey Werro has added another major title to her extraordinary season, storming to victory in the women’s 800m at the inaugural World Athletics Ultimate Championships in Budapest.

The Swiss star delivered a commanding performance, taking control from the opening gun and refusing to surrender the lead as she powered through an absorbing battle against two of the biggest names in the event.

Werro stopped the clock at 1:55.88 to become the Ultimate Championships 800m champion, producing another statement performance on one of the sport’s newest and most prestigious stages.

Behind her, Great Britain’s Keely Hodgkinson fought her way to second in 1:56.26, while the Netherlands’ Femke Broeders-Bol completed the podium in 1:56.74.

The result once again brought together the same formidable trio that featured on the podium at the European Championships, but Werro again proved to be the athlete who could rise above the challenge when it mattered most.

Her Budapest triumph is the latest chapter in a season that has already included records, a successful Diamond League Trophy defence and European Championship gold. Now, she can add the Ultimate Championships crown to a growing list of accomplishments.

Werro’s consistency has been particularly impressive in an 800m event packed with elite talent. Rather than simply relying on a fast finish, the Swiss athlete showed her authority by taking the initiative from the beginning and maintaining enough strength and composure to hold off Hodgkinson and Broeders-Bol all the way to the line.

The victory also underlined the remarkable depth of the women’s 800m, with three athletes separated by less than a second at the finish. Hodgkinson’s 1:56.26 and Broeders-Bol’s 1:56.74 showed just how fiercely contested the race was, but Werro’s decision to dictate the pace ultimately gave her the decisive advantage.

For Werro, this was more than another medal. It was another opportunity to demonstrate that her rise is no passing moment. On a stage featuring established champions and elite rivals, she once again produced the performance required to claim the biggest prize.

For Hodgkinson, the silver medal adds another major podium finish, while Broeders-Bol once again demonstrated her ability to compete with the very best over two laps.

But the spotlight in Budapest belonged unmistakably to Werro.

With another championship crown secured, the Swiss star has strengthened her claim as the athlete setting the standard in women’s 800m running. This is Audrey Werro’s era — and the rest of the field is chasing.

Busang Collen Kebinatshipi has delivered another sensational performance, storming to victory in the men’s 400m at the inaugural World Athletics Ultimate Championship in Budapest.

The reigning world champion stopped the clock at an astonishing 43.39 seconds, smashing his own Botswana national record and moving to fifth on the world all-time list.

Kebinatshipi produced a commanding finish to pull away from his rivals and secure the Ultimate Championship title. American star Rai Benjamin finished second in 44.15, while Jereem Richards of Trinidad and Tobago completed the podium in 44.23.

 Men’s 400m

1. Busang Collen Kebinatshipi — 43.39 NR

2. Rai Benjamin — 44.15

3. Jereem Richards — 44.23

The performance is even more remarkable considering that Kebinatshipi had already rewritten the Botswana record just one week ago in Brussels, where he ran 43.40. In Budapest, he lowered that mark by another 0.01 seconds to establish a new national record of 43.39.

That improvement has also propelled the 22-year-old into rare territory. His latest time now ranks him fifth fastest in history over 400m, placing him among an extraordinary group of athletes who have broken the 43.40 barrier.

Kebinatshipi's victory also caps an extraordinary season for the Botswana star. After establishing himself as a global champion, he has continued to demonstrate that he belongs among the very best one-lap runners in the world.

And there is a major reward for his historic night in Budapest: Kebinatshipi walks away as the Ultimate Champion and $150,000 richer.

From another national record to a place among the five fastest 400m runners ever, Kebinatshipi has turned an already remarkable season into something truly special.

Botswana has its latest sprinting superstar — and Kebinatshipi is showing that his ceiling may be even higher than anyone imagined. 

Marileidy Paulino once again proved why she is the undisputed queen of the one-lap event, powering to victory in the women’s 400m at the inaugural World Athletics Ultimate Championship in Budapest.

The Dominican Republic superstar produced a sensational 49.07 seconds to claim gold, pulling decisively away in the final straight and holding off a fiercely competitive field to extend her remarkable unbeaten run.

Paulino delivered her trademark combination of controlled speed and devastating finishing strength. She remained firmly in contention through the opening stages before unleashing her decisive move down the home straight, where she quickly opened a gap on her closest challengers.

Norway’s Henriette Jæger mounted a strong challenge but could not match Paulino’s finishing speed, crossing the line second in an impressive 49.28. Jamaica’s Nickisha Pryce completed the podium after clocking 49.56, ensuring that three of the world’s leading 400m talents occupied the medals.

The result once again underlined Paulino’s extraordinary consistency at the highest level. She entered Budapest as the world leader after running 48.48 in Paris in June, a performance that also set a Diamond League record. She subsequently remained unbeaten throughout her Diamond League campaign, closing the circuit with a meeting-record 48.64 in Brussels.

Budapest has also become a special venue in Paulino’s career. Three years ago, at the same National Athletics Centre, she captured her first individual world title, marking the beginning of another dominant chapter in her career. She later added Olympic gold in Paris in 2024, further establishing herself among the defining 400m athletes of her generation.

The inaugural World Athletics Ultimate Championship has brought together the sport’s biggest stars in a new winner-takes-the-spotlight format, with Olympic and world champions, Diamond League winners and leading performers competing for ultimate honours.

For Paulino, the occasion once again ended with Ultimate Crown on her arms.

With 49.07 seconds, she did more than win another major 400m title. She delivered another statement of authority, powering through the final straight with the confidence and speed that have made her one of the most dominant figures in modern women’s athletics.

Marileidy Paulino remains unbeaten, remains relentless and, once again, remains the queen of the one lap.

Jakob Ingebrigtsen has made a major decision regarding the remainder of his World Athletics Ultimate Championship campaign, confirming that he will withdraw from the men’s 1500m in Budapest despite producing a sensational performance to win the 5,000m title.

The Norwegian superstar stormed to victory in the inaugural Ultimate Championship 5,000m on Friday night, clocking a season-best 12:59.24 and delivering a devastating finishing kick to defeat Olympic 5,000m champion Cole Hocker and American Parker Wolfe.

Ingebrigtsen’s final 100 metres was arguably the defining moment of the race. The Olympic champion produced a remarkable 12.60-second closing 100m, powering away from the field to secure the $150,000 winner’s prize and underline just how far his fitness has progressed since returning from Achilles surgery.

The victory was particularly significant after what has been an extremely difficult period for the 25-year-old. Earlier in the season, Ingebrigtsen faced serious uncertainty over whether he would even be able to compete at the highest level again. His return has gradually gathered momentum, and his performance in Budapest offered perhaps the clearest indication yet that the Norwegian is rediscovering his formidable racing ability.

But rather than risk pushing his recovering body further, Ingebrigtsen has now opted to step away from the 1500m.

The decision means the highly anticipated showdown with British rival Josh Kerr will not take place in Budapest after all. The two stars had been expected to renew one of the biggest rivalries in modern middle-distance running in the 1500m final.

Instead, Ingebrigtsen is looking beyond the immediate opportunity and towards the bigger picture.

“I’m thinking about 2027… Fitness cannot be faked,” the Norwegian said, signalling that protecting his long-term condition has become more important than chasing another major victory only days after his return to peak-level competition.

The decision comes just one week after an emotionally charged Diamond League Final in Brussels, where Ingebrigtsen finished fourth in the 1500m behind Australia’s Cameron Myers, Kenya’s Phanuel Kipkosgei Koech and American Ethan Strand.

After that race, Ingebrigtsen delivered a fiery assessment of his rivals and questioned the tactics surrounding the pacemaking, particularly involving Hocker. He later acknowledged that there had been “a little too much adrenaline and emotion” when microphones were placed in front of him immediately after the race.

Yet his latest decision shows that beneath the emotion and competitive intensity lies a longer-term strategy.

Ingebrigtsen has already demonstrated that he can compete at an elite level again. His 12:59.24 in Budapest was not simply a victory — it was a statement that the Norwegian remains capable of producing a world-class finish even after months of injury rehabilitation.

Now, however, he is choosing not to gamble with that progress.

For a runner who has spent much of the year fighting his way back from injury, another 1500m race could have offered enormous rewards but also carried unnecessary risk. By withdrawing, Ingebrigtsen is effectively prioritising longevity over one more opportunity for immediate glory.

His message is clear: the comeback is underway, but it will not be rushed.

The 5,000m victory has given Ingebrigtsen confidence, momentum and perhaps, most importantly, proof that his body can once again handle elite competition.

Now comes the harder part — knowing when to stop.

With 2027 already firmly in his sights, the Norwegian has chosen recovery over risk. And after everything he has endured, that could ultimately prove to be one of the most important decisions of his comeback.

Jakob Ingebrigtsen is not walking away from the sport. He is protecting his future in it.