Running News Daily

Ah, summertime! It's one of the best seasons for long trail runs, but it's also the hottest and one of the most difficult times to train.  

As temperatures and UV indices climb, runners in many regions can feel the dew point explode, and that can make it seem like any semblance of fitness gained over the winter and spring is suddenly gone. We can all recall an early summer run that makes us not only question our confidence, but whether we're going to make it through the next few months.

There are notoriously warm races on the horizon, and there's a lot of talk about heat and how to mitigate it: sauna training, layering, topical cooling-all the tools to get amateur and elite athletes alike through challenging conditions. Many of the runners who just raced the Western States 100 had relied on mid-afternoon runs when temperatures were at their highest, as well as sauna or hot water immersion training. The race, as with many other summer and early fall races, typically boasts soaring high temperatures along sections at lower elevations.

For decades, the three most-watched sporting events worldwide-the Summer Olympics, FIFA World Cup, and the Tour de France-are typically held during the hot summer months of the Northern Hemisphere. However, prior to 2012, most of the scientific literature on heat acclimation for athletes was based on laboratory testing and controlled environments, and not from real competitions in scorching conditions. With eight of the hottest years in recorded human history having been logged since 2015, global sport organizations such as the International Olympic Committee have finally placed enormous emphasis on providing up-to-date guidelines and recommendations in order to keep athletes safe.

The COVID-19-delayed Tokyo Olympics in 2021 were the hottest Games in modern history with temperatures soaring into the mid-80s and humidity hovering at 82 percent during the women's marathon. The good news is that it sparked considerable discussion and hypothesizing in sport-science communities about best ways for the athletes and their teams to prepare and endure heat. Ultrarunners everywhere watched as the world's best distance runners implemented topical cooling techniques such as pre-competition ice vests and bags of ice during the marathon-a relatively new or at least a more aggressive tactic to attenuate the impact of heat before and during competition.

Heat is considered an equalizer, an element that everyone has to manage, no matter if you're attempting to train or race through it. But does it have to be a performance-sapping equalizer? Can heat training (potentially year round) be viewed as an opportunity to improve fitness, tolerance, and mental strength for challenging race day conditions?

How Heat Impacts Performance

First up, let's discuss what happens when athletes exercise in the heat. Blood flow to the skin, as well as sweat rate, increase to promote heat dissipation. While aimed at keeping the human body safe, these processes increase physiological strain and the chance for dehydration in prolonged endurance events, leading to a subsequent increase in cardiovascular strain. This creates a chain reaction that negatively impacts aerobic performance. Researchers globally agree that the most salient way to lessen the strain that heat imposes is to perform a heat acclimation period ahead of race day.

Improvements in aerobic performance and thermal comfort achieved through heat acclimation are bolstered by these processes, as outlined in a 2011 scientific article from the U.S. Army Research Institute of Environmental Medicine.

Heat Acclimation

Let's dive even further into what the science says about heat acclimation, when and how to implement it, and what athletes of all levels can do to mitigate heat stress before, during, and after exposure to a hot endurance event.

A study published in the British Journal of Sports Medicine in 2015 provided the first-of-its-kind, gold-standard consensus recommendations for heat acclimation, and remains one of the most cited pieces of recent literature regarding training and competing in heat, along with Julien Periard's comprehensive review from 2021 for the American Physiological Society. In both reviews, the authors discuss heat acclimation, hydration, and cooling strategies as the pillars of successfully competing in the heat.

The authors report that most adaptations happen within the first week and more slowly within the following ten days. In order to achieve near complete adaptations to fully optimize aerobic performance, athletes need to plan for two weeks of focused acclimation. A pre-Tokyo Olympics study from 2020 suggests following the gold standard of 10-14 days of long-term heat acclimation followed by a shorter five-day reacclimation period just ahead of competition (during the taper period) in order to get the most out of "peak weeks" of training without compromising the health of the athlete with the added stressor of heat training.

It is important to note that the average loss of heat acclimation is roughly two-point-five percent per day following 48 hours without exposure to heat. But reacclimation happens quickly. The rate of decline varies from individual to individual and typically occurs at a slower rate than induction to heat acclimation.

The literature favors training in the same environment as the upcoming race, and if that isn't possible, training indoors in a heated room is the next best option. These once-a-day sessions should last at least 60 minutes, at an easy effort, while keeping a close eye on heart rate (preferably at about 75 percent of max heart rate). Athletes should expect to see their heart rate decrease as adaptations continue to occur, and as such, the duration or intensity of the session should be increased in order to maintain the training stimulus.

What if you don't have access to the same outdoor environment nor the set-up to train in a heated room? A study from 2007 demonstrated that 12 sessions of post-exercise sauna bathing at approximately 190 degrees Fahrenheit for 30 minutes at a time over the course of three weeks enhanced endurance performance.

What about dry heat versus humid heat and acclimating to either? The science demonstrates that acclimating to dry heat improves exercise in humid heat and vice versa. But acclimating in humid heat evokes higher skin temperatures and circulatory adaptations. In other words, the stereotypical dad statement: "But it's a dry heat!" holds somewhat true.

Are there benefits to heat acclimation when your race is in temperate or cool environments? A study from 2010 on cycling performance demonstrated a five percent increase in VO2max in cool conditions versus an eight percent increase in hot; a six percent improvement in time-trial performance in cool conditions vs. an eight percent improvement in hot; and an equal increase in power output at lactate threshold in both cool and hot conditions of five percent.

Hydration

Training in hot conditions increases sweat rate, which leads to progressive dehydration (if fluid intake is not increased), causing a similar cascading effect that is essentially the reverse of what happens during heat acclimation: decrease in plasma volume, evaporative heat loss, and cardiac filling all leading to a reduction in capacity to tolerate the effort in the heat.

A 2015 study in the British Journal of Sports Medicine underscores the importance of starting training or competition in the heat in a well-hydrated state with sodium supplementation before and during the event, minimizing body water mass losses during prolonged exercise in the heat, and being sure recovery hydration regimens include sodium, carbohydrates, and protein.

A 2010 study published in the Journal of Applied Physiology demonstrated enhancement and acceleration of heat adaptations, as well as further increases in blood plasma volume by taking in a protein-carbohydrate mix (0.3g of protein/kg of body weight and 3.6kcal of carbohydrate/kg of body weight) within 10 minutes of heat training.

Cooling Strategies

Numerous studies underscore that cooling strategies implemented immediately before, during, or after competition should be used in addition to heat acclimation, not as substitutes. Cooling strategies provide the most benefit during sustained exercise, but should not be used for sprinters. They include both external methods like ice bandanas and saturated towels, cold water immersion, fanning, topical menthol sprays, and internal options such as the ingestion of cold fluids or ice slurries. (Did someone say post-run slushies?!)

Ice bandanas and saturated towels demonstrate the ability to lower skin temperature (without lowering muscle temperature and risking injury) and effectively lower cardiovascular strain. Ice slurries have been shown to be more effective at cooling athletes than cold fluid ingestion, as the latter has also shown reductions in sweating and evaporation. The literature encourages combining techniques (external and internal), as doing so has a higher cooling capacity than the same techniques used in isolation.

 

A meta-analysis from 2020 found that topical menthol spray caused cooler thermal sensation and improved thermal comfort, but no significant differences in sweat production, core temperature, or heart rate were demonstrated. Findings showed external application, warmer environment, and higher body mass indices as improving menthol's effects on endurance performance without compromising the body's response to the heat.

How to Apply This in Training?

For athletes targeting a warm or hot race, we have a few options in how to structure heat acclimation. As a coach, I recommend against adding in heat acclimation as a novel stimulus without an anticipated hot race on the calendar, because most athletes still have a lot of other low-hanging fruit to grab first. (Looking at you, quality sleep!). If you are a highly trained athlete, chat with your coach prior to initiating heat acclimation in the absence of a warm-weather event on your schedule.

If you have a history of RED-S (Relative Energy Deficiency In Sport), work closely with your coach and medical team to be absolutely certain you aren't adding in too much stress to your training all at once. Taking body weight measurements can be a part of hydration monitoring, but it's important to contemplate the pros and cons of doing so. Another consideration is making sure you have a clear picture of your iron/ferritin status prior to initiating a robust heat acclimation protocol, as iron is lost through sweat.

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.