Has The Marathon Become A Science Experiment?

Added: 2026-05-09

[00:00:00]The marathon has been experiencing an explosion of new world records. In the last 10 years, there has been as many records in the men's marathon as there has in every single other male event from the 100 m up to the 10,000 meter.

[00:00:13]And the women's marathon record went from being completely stagnant between 2003 and 2019 to being lowered by 6 1/2 minutes in the last 7 years. Recently, the final major barrier in marathon running was broken when Kenya's Sebastian Sawe and Ethiopia's Yomif Kajela both ran under 2 hours in London.

[00:00:32]Since then, the entire running world has been scrambling to figure out how these runners broke a mark that was once thought to be decades away. And there are numerous different ideas that experts and commentators have come up with. But are all of these theories as credible as some make them out to be? To find out, we are going to do a deep dive into the iceberg of marathon running.

[00:00:51]going from the most commonly held explanations for the wave of fast times down to the most niche specific and overlooked theories out there. I'm sure you know how these videos work at this point. So, let's start off with the factor that has everyone talking, the shoes.

[00:01:08]The last 10 years have seen the introduction of so-called super shoes, which were first introduced in 2016 by Nike. These shoes used a new foam material called PEA, which was a much more reactive and energyefficient compound compared to the traditional EVA foams that previous shoes used. They also had a plate of carbon fiber in the shoe designed to add stability to the squishy foam whilst acting as a spring that runners could power off of. These were almost alien at the time compared to traditional racing shoes where the rough design philosophy was to make them as light as possible whilst giving an athlete just enough foam to make it through the race. However, not only were these super shoes more bouncy than previous iterations, they also competed with them in terms of weight. The company claimed that these shoes gave up to 4% of improvement in running efficiency, which translates to several minutes of an athletes racing time. And indeed, the shoes were so effective that World Athletics had to impose restrictions on them to limit the amount they helped the athletes. Elliot Kipchigible used an illegal prototype version to unofficially break the sub2-hour barrier in the Inos 159 challenge in 2019. And after 16 years of record drought, Bridget Costa smashed the women's world record by over a minute wearing some updated Vaporfly super shoes. For many, this represents the biggest factor for the shift in marathon times. And it's hard to argue against. Even in the last 3 months, Adidas have debuted their new Addios Pro Evo 3, which has the usual Super Shoe technologies, but have also been engineered to be incredibly lightweight.

[00:02:40]At a tiny 97 g, they weigh less than half of Nike's flagship Alphly trainers, which some studies indicate could be worth up to 57 seconds of improvement in the marathon. These shoes were on the feet of four out of five of the top finishes in London, all of whom got massive personal bests. There is little doubt that the shoes have been a huge contributor to the drop in marathon times, but in my opinion, it's just the tip of the iceberg.

[00:03:11]Recently, endurance sports has been going through a nutrition revolution.

[00:03:15]The cycling world is often said to be a few years ahead of the running world in terms of technology due to the greater funding the sport receives. And over the last few years, cycling has seen a carbohydrate boom. It's been well documented that carbs are necessary for maintaining exercise that lasts for multiple hours. As whilst carbs are a key source of fuel for athletes, the body can only store up to 2,000 calories of it at one time, which is simply not enough for an all-out marathon. And the athletes who are unfortunate enough to not give their body adequate fuel during a race hit what's known as the wall.

[00:03:48]This is where the body completely shuts down due to not having enough energy to function, resulting in people collapsing and being physically incapable of going any further. To combat this, athletes take fast digesting carbohydrates, usually in the form of sports drinks or energy gels during their race. And not long ago, the general guidance for optimal endurance performance was to take around 30 to 60 g of carbohydrates an hour, with higher amounts showing diminishing returns due to an increase in side effects. That many carbs in such a short time whilst exercising causes gastrointestinal issues, which is the last thing you want to be dealing with during a race. However, athletes have recently found novel ways to overcome this problem. During training cycles, they would progressively overload their system with carbohydrates to develop a GI tolerance to the nutrition, and this has allowed them to consume more carbs during race day, leading to boosted performance. Cyclists did this first, often canning down up to triple the carbohydrates as before. In this area, the marathon has lagged behind, which is in no small part due to the fact that running is a much more aggressive action on the gut compared to sitting on a bike. But to combat this, in came the company Morton, who patented their hydrogel technology in 2015. This encases the carbohydrates in a protective gel layer, allowing them to be more quickly absorbed by the body and reducing stomach irritation. And now athletes who were incapable of consuming more than 60 grams of carbs can now knock back more than 100 grams without a hitch. In fact, Morton worked closely with Sawe in the buildup to the London Marathon, making six trips to Kenya during his training program. This allowed him to consume up to 115 g of carbs an hour during his race, which certainly helped with his performance.

[00:05:28]Yum Kajel also worked with a nutrition company to fine-tune his own intramarathon diet. But it doesn't just stop with carbohydrates as there is also bicarbonate of soda is known to boost endurance as its alkaline composition reduces the increase of muscle acidity.

[00:05:50]This is the burning feeling you get when exercising. Now this was generally only seen to be useful for the shorter distances like the 8 and 1500 meter. The marathon was run too slow for muscle acidity to really matter with the larger limiting factor being fuel depletion and accumulated fatigue in the muscles. But with the advent of super shoes and greater carbohydrate loading, the event has shifted to be slightly more lactic focused. Which means that by carb is now a more useful supplement for the longer events. When Morton also used the hydrogel technology on the barbar doses, it also meant that many more athletes could take the supplement without getting GI stress. But now we will move on to something that appears incredibly obvious at first, but is actually much more nuanced than people realize.

[00:06:39]For most of modern marathon history, the general weekly mileage for the top athletes has hovered around 180 to 220 km a week. Whilst they could theoretically run more, the athletes were bottlenecked by their ability to recover between sessions. And the general perception was that those runners who ran higher mileage of up to 280 km a week tended to plateau very quickly in their careers. For instance, Dennis Kmetto broke the world record in 2014, becoming the first man ever to run a sub 203 marathon. He was reportedly running between 250 and 280 km a week before the race. After breaking the world record by 30 seconds, he would DNF in two marathons the next year and would never run within two and a half minutes of his personal best again. His training partner, Emanuel Matai, who ran a similar mileage, did admittedly have a more consistent career, but again saw his performance plummet after his personal best finished behind Kmetto in 2014. Generally speaking, the body has a limit on the amount of training it can do. There's a reason athletes aren't running 500 km a week. However, a narrative has recently become popular that today's athletes are running higher than average mileage. Sebastian Sawe ran 240 km a week before London and attributed this mileage as the biggest contributor to his sub 2 performance.

[00:07:56]Tig Zepha, who won the women's race in London, similarly runs 250 km a week.

[00:08:02]So, it seems natural to think that this extra training load has helped the increase in faster times. But here is the real kicker. The idea that the top athletes are running more miles today is actually a myth. It's a common sentiment we are hearing a lot about because on paper it makes loads of sense. More miles should mean faster times. But I checked the top 10 fastest male athletes peak mileage in the present day and compared it to the top 10 runners as of 2015. And you know what? The average weekly mileage is almost exactly the same. Plenty of runners do exceed the 220 km guideline, but that applies to both lists, and there are of course notable exceptions. Kajela ran 200 km a week before London, and Kipla was repping around 210. I know these guys are new to the event, but they're still second and third of all time. I'm not really sure where this idea came from because I believed it going in. Maybe runners are doing more kilometers in their buildup, but is still peaking at the same max volume as the previous decade. However, without detailed data that simply isn't available to the public, we can only conclude the mileage idea appears false. However, there is perhaps something deeper going on.

[00:09:12]Runners aren't adding volume, sure, but they are instead getting more out of each training session, running slightly faster, more intense, and more precisely targeted efforts without increasing overall fatigue. And I have three reasons for saying this. For one, yes, super shoes do play a big role. The greater amount of cushioning allows for the legs to be better protected and therefore more able to recover between sessions. So paces that previously would have caused a little too much fatigue to be worth doing can now be running training. And we are starting to see the athletes who have been able to benefit from this their entire lives rather than athletes like hip chokei who only use super shoes for half of their time at the top. Secondly, the previously mentioned innovations in nutrition also allow for better recovery from long runs. But I think there is a third factor going under the radar.

[00:10:06]There has been an increase in the precision and number of methods athletes have to measure their bodies. When training at such a high mileage, most runs need to be done at a very specific effort level. It's super important you don't overcook individual sessions when you have to run 20 km in a few hours.

[00:10:22]Traditionally, athletes have relied on heart rate data and perceived effort, which are valid metrics. But in the last 5 to 10 years, we have seen a huge leaning into the data collection around running. Lactate testing has become the new norm, where athletes carefully measure their blood lactate concentration during sessions and compare it to their baseline. Heart rate monitors are becoming more accurate.

[00:10:43]Power output is another metric athletes are considering. We're also seeing this outside of training. Think of the popularization of blood glucose and sleep monitors over the last few years.

[00:10:52]But it doesn't just stop there. The rise of the so-called Norwegian method of training is the perfect example of how there is a cultural shift in the way runners train. Marius Bachan, the founder of the Norwegian method, did not invent the idea of training at your lactate threshold. In fact, he says on his website that he was inspired by watching Kenyans run at this pace in their training. However, what he did was systematize and quantify the data behind training at your lactate threshold.

[00:11:18]Whilst the Kenyan method was generally more intuitive and feel-based, the success of athletes like Yakabinga Britain who use this method helped massively popularize it. Athletes don't just have more ways to measure their body. They are encouraged to do so by the new cultural shift in favor of quantifiable science-based training, which I think has helped them recover better between sessions, leading to higher quality workouts. But with all of this in mind, I now want to get on to the speculative long-term factors.

[00:11:50]East Africans have been known to absolutely dominate distance running over the last few decades. Of the top 100 female marathon runners, 89 were born or have East African heritage with that figure rising to 96 out of 100 for males. And yet whilst this trend has remained on the roads on the track we are seeing that East Africa dominance is diminishing for men. The top 10ness in the middle distances remain diverse and even in the 5k and 10k many of the best athletes hail from non-affrican nations.

[00:12:18]A key reason often cited for this is that the track is now much less profitable than the marathon especially over the last 20 years. And as a result we are seeing an East African economic migration to road races therefore leading to bigger talent pools in the event. But is there any good evidence to back this up? The main way for athletes to specifically make money through the track is the Diamond League, which is notorious for its pitiful prize money.

[00:12:43]Since its inception in 2010, top athletes who win their event can hope to make $10,000. The real issue is that this money has barely increased in the last 16 years. The only positive change that has very recently been made is that there has been double prize money offered in both the standard and final meets for select events. But this was too little, too late. This graph shows the real-time drop in value of that prize money from the Diamond League's inception in 2010, and the results are pretty stark. It has effectively been reduced by 30% from inflation over the last 16 years, with recent changes still putting them in the red. So surely the marathon is more profitable, right?

[00:13:21]Well, in nominal terms, it seems plausible. Most major marathons offer significantly more than the Diamond League for top finishes. What's more, there are added bonuses for records and fast times, meaning an athlete can take home several hundred,000 from a great performance. But the actual prize money available to the runners has remained just as stagnant as the track in the last 15 years and in fact has seen cuts in certain areas. So although the roads are probably still more profitable than the track, there isn't much evidence to say that they have become increasingly more profitable over the last 16 years.

[00:13:52]So where did this overall idea come from? I think it comes from the hidden way that athletes are paid, appearance fees and sponsorships. It's no secret that running has become massively popular over the last few years, and with it, the products and aesthetics surrounding the sport have skyrocketed in value. 110 million people took up running between 2022 and 2025, representing a 17% increase in global running populations. And whilst from my experience most of these runners don't tend to be super interested in the professional scene, there is inevitably going to be a trickling down effect due to the higher demand of running products. And the marathon simply has more things an athlete can be sponsored by as well. Nutrition supplements, shoes, race kits, watches. Whilst these do apply to the track to a certain extent, the market is much bigger in the marathon. The running boom comprises mostly of people looking to run for fitness or fun. Most of these people pick the roads as it's easier to sign up for compared to a track race where you often need to be affiliated with a club to compete. I also think that the perceived culture around road running is much more friendly and easygoing compared to the serious and competitive nature of track racing. So, while sponsor opportunities have potentially risen in the track, they probably haven't done so to the same extent as the roads. I absolutely can believe that the marathon has become more profitable over the last 5 to six years, but it's hard to get any concrete information.

[00:15:13]And I think it's worth noting that this is more due to private interest in the sport rather than the marathons handing out more prize money. But with any increase in the number of runners means we will likely see more world records broken. And this leads me nicely to my next point.

[00:15:31]One thing experts like Steve Magnus have suggested is that there are now more people switching to the marathon directly rather than taking the more traditional route of starting in the track world and transitioning to the marathon later in their career. As a result, the theory goes that we now have a larger number of specialized marathon runners like Sebastian Sawe, for instance, who have been training for the event their entire lives. And these presumably superior athletes are part of the reason we are seeing more records falling. It sounds like a really compelling argument, but I wanted to test this idea. Here is a list of the top 25 fastest male athletes as of May 2026. I aggregated all their backgrounds by checking their world athletics profiles to see what their first races are and how much they competed in different formats. I then ranked each of the athletes into one of three categories. Road background, track background, and a mix background. As a case study, Sawi is clearly a road specialist. He has run road racing since the start of his career and barely touched the track. Kaja, by contrast, is clearly a track specialist. He had a strong career in the mile up to the 10K before transitioning to the marathon.

[00:16:38]Kiplo is a mix of both. He has run track races very early into his career, but was always mixing in the roads and he ran his first half marathon at the young age of 20. With this system in place, I then did the same for the top 25 runners as of 2015. If more athletes are directly skipping to the marathon, we would expect to see more road oriented athletes in the 2026 list. But actually, the numbers have barely changed at all.

[00:17:02]The same is true on the women's side as well with a similar proportion of each background between the different eras.

[00:17:08]It's possible that this may have an effect on the depth of the marathon or people chasing national records. But as far as explaining why world records have been falling year on year, the data simply just doesn't support that theory right now. It's an interesting idea, but we're going to have to wait for more evidence to come out. And now we can move on to the most speculative, but also potentially the most consequential factor of all of these.

[00:17:36]Now, we are getting into the real weeds here. As we have already mentioned, East African talent has dominated the marathon for decades now. And given just how concentrated the talent pool is, it makes sense that the well-being and population of those regions that foster all that distance talent has some effect on the overall talent pool. And of course, if the talent pool is bigger, records are more likely to fall. With this in mind, I decided to look at the growth in population in the key areas where most marathon runners are born.

[00:18:02]The top runners are concentrated in specific high altitude pockets of Kenya and Ethiopia. And here is the growth in population between 1980 and 2000. Since marathon runners on average peak in their late 20s to early30s, the 1980s generations are in their prime around 2010 to 2015, and the 1990s runners are essentially peaking now. As we can see, the population of these places has massively grown, which would theoretically indicate that the running talent pools have grown as well. It's undoubtedly a broad argument. There are, of course, many more factors than population size that go into fostering a sporting nation. But from my understanding, other key factors like infrastructure, culture, and economic prosperity are only improving nationwide to foster more talent. And as a general principle, if there are more talented people being born, there are more talented people going to be racing. And as one final note, we know that Uganda has been emerging as a third big player in distance running with Joshua Chapter and Jacob Kiblimo leading the charge.

[00:19:01]Uganda's distance running hotspot is much smaller in population than Kenya and Ethiopia's ones, but it has seen a nearly five-fold increase in population over the last 45 years. When graded on proportional growth compared to Kenya and Ethiopia, it looks like this. So, my personal prediction is that in 15 years time, Uganda is going to be rivaling Ethiopia and Kenya on the all-time lists. So, when 2040 rolls around, check back on this video to see just how right I was. If you want to see the history and story of the sub to our marathon, including how the new Adidas prototype shoe changed the game, then click on this video here. Thank you very much for watching and I'll see you in the next one. Happy training.