Stunning results at the top of the field. Some interesting takeaways on both fuelling and shoes.
Maurten spent months working with Sawe and other runners getting their gut capacity trained so they could absorb and burn 100 carbs per hour[0][1]
> The Maurten research team was embedded with Sawe’s team in Kenya for 32 days across six trips between last and this April. They were training his gut to absorb that load by mimicking race-day protocol in training. The hydrogel technology they have developed over the past 10 years now allows athletes to absorb 90–120 grams of carbs per hour without GI distress.
Second is the shoes. Adidas Adizero weigh 96 grams[2] with new foam tech and new carbon plates
Nike and INEOS spent millions over years to get Kipchoge to a sub-2 in artificial conditions, and now the elite end of the field are knocking that barrier out in race conditions. Unreal.
Running tech and training have been revolutionized in the past few years.
burning a hundred calories an hour is trivial. Most people will burn 100 calories per mile when walking or running, and more if moving as fast as these athletes, and many, many humans can do this for far, far longer than 2 hours.
It's the absorbtion that's the challenge. Maurten is not somehow alone in the particular stuff they've developed - ultra runners are generally shifting up into the 90-120 gram/hr range (or beyond!), using a variety of different companies' products. The gut training protocols for this are widely discussed in the world of running for almost any distance above a half marathon.
GP left out the units but is clearly talking about grams ("absorb ... 100 carbs per hour"), not calories (no one needs training to absorb 25g/hr). Carbs are 4 kcal/g. 100g of carb (400 kcal) an hour isn't replacement level for even casual athletic efforts, but it does mitigate the loss of glycogen in muscle somewhat.
I've read that even if you absorb it all, there's some question about whether it's useful. This Alex Hutchinson article suggests, among other things, that it may spare your fat stores rather than your muscle glycogen:
> Even if you can absorb 120 grams per hour, it might not make you faster. In Podlogar’s study, cyclists burned more exogenous carbs when they consumed 120 rather than 90 grams per hour, but that didn’t reduce their rate of endogenous carb-burning—that is, they were still depleting the glycogen stores in their muscles just as quickly.
Where does discussion on gut training occur? All I know is you need a 5:4 ratio of glucose to fructose? Then when you train, you use the gels and the more you do it, the more capable your gut gets at absorbing without distress.
Wow so he was absorbing 400 calories per hour with this gel, but he was likely burning 3-4x that amount (or even more) while running 13.1 miles per hour!
In a two hour race that’s still 800 bonus calories, that’s something.
The race to tolerate lots of carbs is usually something you think of in 8 hour Ironmans. The good part is you can do most of it on the bike, which is much easier to eat as you go. As far as I know, many elite runners were doing like 50% water, 50% sports drink and consuming way under 100g.
> As far as I know, many elite runners were doing like 50% water, 50% sports drink and consuming way under 100g.
This used to be true, and is still true for many athletes up the marathon distance. Above that, however, the momentum has swung heavily to very high carb intake. Most (though not all) of the world's best ultra runners (we're talking 7:00 min/mile pace through mountainous terrain) are picking this up, with many getting to and beyond 100g/hr of carb consumption.
Because calories simply do not matter. At high intensities of working out, it's the amount of carbohydrates you can consume that allow more fuel to be burnt.
"In the aerobic exercise domain up to ~100% of maximal oxygen uptake (VO2max), CHO is the dominant fuel, as CHO-based oxidative metabolism can be activated quickly, provide all of the fuel at high aerobic power outputs (> 85-90% VO2max) and is a more efficient fuel (kcal/L O2 used) when compared to fat."
Calories do matter (obviously, as energy intake is the entire point) but as you note the specific form that the fuel takes matters. However "carbs" is a catch all that includes plenty of things that (I assume) would be of similarly minimal use in this scenario. The calories need to take a very specific chemical form for this to work.
The wording is certainly confusing here, but yes the calories don’t matter as much as the form. Eating protein and fats simply give you minimal useful calories during the race. Even most carbs won’t be useful if they are more complex.
It’s also confusing that most nutritional labels say “calories” (Cal) when they really mean kilocalories (kcal). And those are different from regular (‘small’) calories
(a measure of energy needed to heat 1g water 1c).
1 food calorie as listed on a food label is enough to heat 1kg of water by 1c
(If the nutritional calories in the drink had been only the same number of thermodynamic calories, the drink would have been energetically negative for the body because of its low temperature.)
I normally consume 90g of carbs per hour when long distance biking, so do a few other riders I know. No GI issues. I use Skratch some other guys like Precision.
Yeah, I just literally use table sugar, which is 1:1 glucose:fructose. Maurten et al using 1:0.8, close enough! And I don't believe the hydrogel thing is any magic, just marketing.
But yeah, this is a thing. There is some gut distress for sure at higher levels of intake. See guy finishing second -- still under 2 hrs! immediately puking, which is fairly common at the high intakes. I've heard of Blumenfeld (the triathlete) taking like 200g/hr or more. Insane. Though he's had some epic GI disasters too, lol.
adidas introduces the Adizero Adios Pro Evo 3 – the lightest and fastest Adizero shoe ever, weighing an average 97* grams.
The race-day shoe represents the culmination of three years of cutting-edge research. It is 30% lighter, delivers 11% greater forefoot energy return, and improves running economy by 1.6% compared to its predecessor - making it a record breaker before it’s even laced up.
The shoe will launch with a highly limited release, with ambitious runners able to sign up for the chance to get their hands on a pair from April 23. This will be followed by a wider release in the fall marathon season. The Adizero adios Pro Evo 3 will cost $500/€500.
For other marathon racing shoes, Google says:
The Nike Alphafly 3 is the lightest in the series, weighing approximately 7.0–7.7 oz (198–218g) for a men's size 9, and 6.1 oz (174g) for women's sizes.
The PUMA Deviate NITRO™ Elite 3 is exceptionally lightweight, typically weighing 194g (6.8 oz) for a men's size 8 (UK)
Most superfoam shoes actually last longer than older EVA-based foams:
> Improved durability: Supercritical foaming produces a more consistent cell structure in a midsole. This should translate to pressure and weight being more evenly distributed, which should lead to greater durability of the midsole. “We’ve done a lot of testing of what foams look like on a dynamic impactor fresh versus 300 or 500 miles later, and we see less degradation in those materials longer-term,” FitzPatrick says.
> At least in terms of the midsole’s life span, super foams may have done away with the conventional benchmark that running shoes last about 300 miles. “I think it’s a dated standard,” Caprara of Brooks says. “It’s an easy go-to to help simplify. But every foam is different, and it’s not just the foam—it’s how it’s constructed, the shoe’s geometry, the rubber underneath it. There are so many factors. If I were to tell you the Glycerin Max lasts 300 miles, that’s probably less accurate than it is accurate. It’s probably closer to 500.”
You don't need to be competing on the world stage to enjoy some of the benefits of Alpha flys or those pumas. 500 for the new Adidas does seem a little silly though.
While the foam may last longer than older EVA foam shoes, the outsoles of the shoes have gotten ridiculously thin these days.
The continental rubber outsole on these Adidas Adios Pro EVO 3 shoes are so thin (less than two sheets of paper, I think), that they don't even appear in side/profile views of the shoes. The outsole doesn't even extend the length of the entire shoe, it stops around the middle of the shoe. So heel strikers aren't welcome and will have loads of fun in wet weather. see https://www.adidas.com/us/adizero-adios-pro-evo-3/KH7678.htm...
In general, these high stack, forward-leaning shoes are meant for going straight ahead - imagine ladies' high heel shoes with an inch and a half of foam on the bottom - any sharp turns will force the runner to slow down or they'll twist their ankles. Looking at the London Marathon course, https://www.londonmarathonevents.co.uk/london-marathon/cours..., there's about twenty ninety-degree or sharper turns.
Feel a bit bad for Yomif Kejelcha who also broke the 2-hour mark, with this being his first competition marathon, but managed to neither break a record nor win.
While I know competitors want to always strive to be the best, as a completely normal human who struggles to complete a half marathon under two hours, I do not feel bad for the guy. He’s still one of the only two people to do it (outside of the very controlled run from Kipchoge). Not a feat to feel bad about at all.
The majority of people in the world cannot complete a half marathon, let alone under two hours. I was pleased to train enough that I managed under three. You're doing great!
I'll admit I'm not familiar with running, but in other sports it's not uncommon for amazing early career athletes to hold back a little bit on their first attempts.
It's easier to draw attention (and therefore sponsorships) if you leave some room to improve on successive attempts. It's riskier to give everything up front and then risk plateauing or regressing in your subsequent attempts.
Super shoes. Most shoes have carbon plates in them now, they act as a spring, storing energy and propelling athletes forwards.
Better understanding of fuelling. Most athletes are taking between 100-120g carbs (sugar) per hour. Bicarbonate of soda has also been effective.
Better planning tools. Athletes look at elevation, headwind, tailwind and will plan a strategy around going harder into the hard stuff and knowing when they can back off and rest.
And to be honest, probably a metric tonne of PEDs (performance enhancing drugs) - unfortunately this is very common across all sports at the top level.
> probably a metric tonne of PEDs (performance enhancing drugs)
Note that Sawe funded extra testing drug testing for himself for the 2 months before winning the Berlin marathon. The testing followed Athletics Integrity Unit protocols (so surprise testing etc):
This is news to me and genuinely impressive. Putting extra work into ensuring your attempt at one of the few records that will last the duration of humanity is damn smart.
> Most shoes have carbon plates in them now, they act as a spring, storing energy and propelling athletes forwards.
This seems unlikely to be true, although it is repeated in every article I read about carbon plated shoes. The people that study them in a lab environment seem to disagree. See some of the papers here:
Yes, most of the studies show there is a very large individual variation. The original 4% figure and similar studies were an average of something like 1-7% across runners.
Also interestingly, the shoe in this record uses much less carbon than past shoes, both saving weight and allowing even more super foam where much of the energy return comes from. Though there so much variance in shoe design and materials there are only theories on how much comes from the plate vs foam vs stack height vs weight vs other factors.
Quite possible there's a psychological benefit from super shoes, they certainly feel fast. Though there are enough plausible mechanisms it's unlikely to be the major factor.
As a 16 year wearer of mostly barefoot shoes, "barefoot" for me is about comfort in general day to day activity. It isn't a specialized tool and certainly isn't the obvious choice for extreme environments.
If I'm going bouldering I absolutely cram my toes into a tiny rock climbing shoe, because it allows me to stand on ledges I couldn't without the extra support from the shoe.
That being said, if barefoot generally feels good to you and you're not chasing the pinacle of performance it's probably a perfectly fine choice for your recreational runs.
Was the barefoot movement ever about running faster? I always thought they sold injury prevention by strengthening tissues that running shoes tend to over support.
Yes, that was the claim but it was never really backed by evidence. Vibram settled a lawsuit over false claims that their minimalist shoes reduced the risk of injuries. (I still like those shoes myself and use them on some slow recovery runs.)
This topic deserves so much more nuance, but it's always reduced to "barefoot running doesn't work" in internet forums. In every articles about the harm caused by barefoot running I've read, those reported injuries all end up being overuse injuries. The article you linked is specifically about bone marrow edema, which is basically bone bruise. Other possible injuries include muscle and tendon soreness.
If this were a bodybuilding discussion, you would get advice on how to manage DOMS symptoms and how to plan your loading schedule, nobody would say that weightlifting "doesn't work" because a beginner got sore after lifting a 80kg barbell for the first time. But people has been conditioned to think that running is a purely cardio activity, so we don't talk about how the muscles and tendons in the foot need to be loaded up gradually just like your bicep.
Barefoot running is a weightlifting activity. Your calf muscle has to lift your entire bodyweight for the forefoot stride. "No pain no gain" applies. Proper posture and techniques are important. Proper workout schedule and loading plan with rest days are important. Sufficient protein intake are important.
> going harder into the hard stuff and knowing when they can back off and rest.
Why is going harder in the hard stuff and easier in the easy stuff more efficient or faster than vice versa? I imagine arguments either way:
Going harder when it's easy gives you higher ROI. Or maybe going easier when it's hard is just too slow. And maybe that is too simplistic: Maybe it depends on how hard; that is, maybe there is a threshold.
Is there also something beneficial about the shirt he wore? It has a unique embossed pattern on the chest. Is it just a nice design or does it also provide aerodynamic or heat wicking advantage?
I can sort of visualize an aero improvement. If wind hits you flat on it goes all around and right against you, and it can bump into itself and then back on you since it's almost directionless. However if you have 'needles' coming out it gives the wind a 'direction' other than straight at you, lessening the pressure against your front.
Good eye! Almost like an inverted golf ball. If I remember correctly from undergrad aero, purpose of dimples on golf ball is to detach/disrupt more of any laminar flow earlier as air passes around the ball, which decreases drag. Golf balls travel way faster than a runner, but possibly still has some minor effect?
It's his first marathon ever, but he's a very experienced runner. It would be hard to find a better prospect for a good first marathon. He's a multiple (former) world record holder and medalist at shorter distances from the mile up to half marathon. His half marathon is still 2nd all time.
I wouldn't have predicted this out of nowhere, but if you told me a marathon debut went this well and asked me to guess whose it was, I like to think I'd have come up with Kejelcha in my top few picks.
That said, great 5000/10000 athletes don't always have great marathon careers. An example from this race is the world record holder at both those distances, Joshua Cheptegei. He's run several marathons but none spectacular by his standards. He was in this race too but 7 minutes back.
I'm a runner, and it's a bit sad that distance running is not longer purely about the runner.
Based on the quote below, next thing we will see is a "constructors championship" similar to F1 for winning shoe constructor in the 'major' marathons :-(.
" This dominance continued in 2024, with adidas athletes wearing Adizero models winning six out of 12 World Major Marathons – more than any other brand."
The winner is doing a completely different sport from me. I never even see the winners at a marathon. They are long gone by the time I get to the start line, and they've gone home by the time I finish.
There are age group leaders as well. That's perhaps a hundred people, of the tens of thousands running next to me.
Marathons are about running my own pace. The fact that there exists a world record is a piece of trivia.
It was never about the runner, it has always been about technology and innovation. Shoes tech is just one of them. Better nutrition, novel training techniques, better air quality etc.
Of course innovation in shoes will have a bigger marginal impact (because physics).
There's something about the London course today that made for very good running.
Three athletes broke the men's world record. One athlete broke the women's world record, and three were in the all time top 5. An Irish record was also broken, likely other countries too that I'm not familiar with.
Not to take anything away from the achievements. Incredible running.
To add some color here:
It is very helpful to have someone pace you so that you can run an ideal pace without worrying about whether you are running the right speed. However, the rules require that pacers start with you [0], which means that by definition if you are running faster than anyone has ever gone before you have to run some of the race alone.
However, because marathon are often mixed gender and the best male runners are significantly faster than the best female runners, it is possible for a woman to be paced from the gun to the tape by a male runner. For this reason, there are separate records for the women's marathon for women's only events.
[0] This is one of the things that made Kipchoge's original sub 2 result not record-eligible.
I stand corrected, but I don't think this changes my point at all.
She broke the thing that the IAAF have gone back and forth on calling "the world record". It's the relevant record for this event - there was no more chance of her beating the man-paced record than of beating the men's record or the Le Mans lap record.
> Very few mere mortals could run that fast for even 100m.
That works out to roughly a 16.7-second 100m. While certainly not crawling, that would be a fairly average pace for a fairly fit middle- to early-high-schooler with a bit of practice.
Yes that’s insane to maintain for a marathon, but it’s not even remotely out of reach for 100m for most relatively-fit people at some point in their lives.
I think it's even slow for high schoolers. I didn't practice that much and ran 100m in 12.5s from rest at my peak. 4s slower is snail pace. I think most in my class could run that fast (or slow).
I agree. I ran mid 16s in 8th grade, and was in the 14s in high school, with the only training being whatever we did in gym class. But I do also look at the sheer number of overweight kids these days and figured, well maybe mid-16s is actually a reasonable average point.
Here's a random high school in Northern California. Everyone on the team is beating 16.7 seconds in the 100m. For the 1600m there are six kids with times under 4m30s and another seven with times under 4m40s, all in the last month.
Not sure that disproves the point :) Most people have never been anywhere close to competing with the top 6 athletes at a high school with ~2k students.
OK, so let's do the math. There's about 25k high schools in the USA. Let's suppose they all have a track team, and let's assume that they all have 5 team members who can break 04:30 for 1600m. Sure, at some schools that's too few, but at others it is too many.
That gives us 125k high schoolers in the USA who can break 04:30 for 1600m. There are about 18M high school students. So of just the high school population alone, about 0.7% of them can do this.
Assuming there are the 4x as many adults that can do this as there are high school students, that gives us slightly less than 0.2% of the total US population capable of this.
Sometimes they have big running machines with a crash mat around them running at 2h marathon pace at running shows. I’ve o ly seen them on video - no one can keep up with it for more than 30 odd seconds. It’s INSANE they are running this fast.
Also bear in mind running a single mile under 4 mins was considered impossible for a long time.
We used to be amazed when I ran cross country in high school that these pro marathoners would best all of us in our approx 5K(3ish mile) races and then go on to repeat that distance multiple times.
Those shoes are gonna sell like crazy now but it would be hilarious if they were to be found to have been giving an unfair advantage because of some mechanical property of the shoe.
Reviews say that they have very very good, but not record breaking energy return and shock absorption. But what they are is insanely light at sub 100g.
For a while it was all about getting the lightest shoes, because picking up heavy shoes slowed you down. Then the energy return (pebax foam, carbon plates/rods) became the main focus because the weight didn't matter as much when the shoe was literally springy. Surely this is now going to spark a race for the optimal balance between weight and energy return.
The big improvement then was a carbon plate. Adidas (and others) followed suit. The subsequent improvements since then have been marginal but the margins are thin at that level. In this case the big advancement has been the weight of the shoe.
EDIT: Also it's worth noting these shoes are $500 retail. Adidas will for sure get a boost in sales from this, but there's definitely competition in the $200~$300 marathon running shoe space that won't solely draw everyone to Adidas)
Well, the marathon record has been broken 53 times since the early 1900s. So, there are a lot of factors at play. Better training, better nutrition, better tactics, and, yes, better shoes.
The advancements in shoes have made a measurable impact, but there are lots of optimizations being worked on.
The previous official record was Kelvin Kiptum's time of 2:00:35 in 2023. Eliud Kipchoge did 1:59:40 in 2019, but that wasn't record-eligible as it was held under controlled conditions. Source: The article.
Weather and course conditions were good but not perfect. There is potential to take a few more seconds off the world record in slightly colder conditions and on a course with fewer turns. I wouldn't be surprised to see someone run 1:58 in the next few years.
Pacing is a big part of endurance sport. If you're in the lead you know intellectually you want to pace for sub-2 hours, but if you're watching someone beat you maybe it gives you the extra edge?
It does sound like the course and the weather made it more likely to happen. And technical advances in shoe composition.
That's not a description of how the pacing for this race actually happened.
> The leading men went through halfway in 60 minutes and 29 seconds: fast but not exceptionally so. But it turned out that Sawe was merely warming up.
Between 30 and 35 kilometres, Sawe and Kejelcha ran a stunning 13:54 for 5km to see off Kiplimo. Yet, staggeringly, more was to come as the pair covered kilometres 35 to 40 in 13:42. To put this into context, that time is two seconds faster than the 5km parkrun world record, set by the Irish international Nick Griggs.
It was only after a 24th mile, run in 4:12, that Kejelcha wilted. But still Sawe kept going. Astonishingly, he crossed the line having run the second half in just over 59 minutes.
“Before 41 kilometres, I’m enjoying, I’m relaxed,” said Kejelcha, who had won silver over 10,000m at last year’s world championships.
“My body is all great. At exactly 41 kilometres, my body stopped. I tried to push, but my legs were done.
Sawe, though, powered on to set the fastest official marathon time in history. For good measure, it was also 10 seconds faster than Eliud Kipchoge’s unofficial 26.2 mile best, set in Vienna in 2019.
And the only place this appears on ESPN is if you click on "Olympics," which has nothing to do with this race. Where coverage should be: on the home page.
It’s certainly noteworthy and interesting but I could see how Running as sport isn’t popular enough for front page. Especially during NBA and NHL playoffs, NFL draft, and whatever else might be going on.
If this happened at Chicago, it would be front page news. Boston and NY aren’t WR eligible. Since it happened in London, place it behind soccer in the priority list.
Great achievement. Worth remembering also the previous world record holder, Kelvin Kiptum who sadly died at 24 in a car accident a couple of years ago.
> Previous research indicates improvements of 2–4% in running economy (RE), which translates into an approximate 1–2% improvement in running performance when running in these shoes.
A 1:59 half marathon time is achievable for pretty much anyone who doesn't have a serious physical disability and is willing to put in the necessary training. I've done it a few times and have no particular talent for running.
That's a 9m10sec per mile for 2 hours. While I'd agree that there are millions or even billions of people who could train to do that, I think it's wrong to suggest that "pretty much anyone" could do that.
My predicted half time is under 2 hours and I was sedentary for years before starting to run 9 months ago, and I'm 40 years old.
Endurance sports are quite accessible and don't require that much time, effort, or talent to get way better than the vast majority of people, it's just consistency.
I've been an endurance athlete most of my life, running 100 miles at 17, a 5:30 mile at 50, and lots of other stuff in between. I know that a 9min/mile pace is "easily achievable" by many folks, which is why I noted that millions or billions of people could do this. Nevertheless, I think it is really important to not overstate how achievable this is - there are many more people who could not do this than could, I think.
FWIW, that now includes me, as a 62 year old. I can hit 6:30 pace for 400m, but find it almost impossible to get under 10:0x for a mile. And that's even after 6 months of training for a 50 mile trail race.
Insane; and second place was sub-2:00 as well. Relegated to trivia questions for the next decade.
It would be interesting to adjust this speed to account for the insane advancements in shoe technology over the last decade. Could it be as simple as measuring the delta in median marathon performance? Then look backwards to, say, 1996 and see what the technology-adjusted 2:00 mark is.
I suspect there would be larger deltas due to improvements in nutrition and fueling. As another poster has mentioned, today's runners are ingesting so many more carbs per hour than 20 or 30 years ago. And if doping trends have changed over time, that's another factor. (No clue either way, but it's a potential factor.)
There's been lots of research into shoes though, so you might be able to work something out. For instance Jack Daniels (the running coach, not the beverage!) found that adding 100 grams to a running shoe increased aerobic effort by around 1%.
The confounding variable is higher carbohydrate intake based on optimizing the glucose/fructose ratio and improved techniques for gut training. That happened at about the same time as the new carbon fiber shoes so it's hard to isolate how much impact the shoes had alone.
> Could it be as simple as measuring the delta in median marathon performance?
The popularity of running waxes and wanes - and the performance of the median runner varies with popularity.
Back in the 1980s the average half marathon finishing time was 1 hour 40 minutes - whereas today it's a little above 2 hours because there are a lot more people particpating.
Kipchoge broke 2h a few years ago, but it was on a closed, low altitude track, with a fleet of rotating runners in front of him, providing wind blocking/drafting as well as pacing
Amazing these guys did it in a real race with no one in front of them (at the end at least)
Such a purist should also note that Pheidippides was likely the runner who ran to Sparta and back, hundreds of miles, the preceding week to ask for their aid at Marathon.
> I for one love the advances in technology in something as supposedly simple as a shoe. And maybe I'll get to use it on a hike in a few years.
These shoes are practically disposable. They trade longevity for noticeable gains in performance. Even the tier below don’t last very long. This is not tech that is going to filter down to your hiking boots.
But the initial tech on an F1 car was not made for 200k miles either.
Even if the full tech stack to make it all work - material science, physical layout and construction - doesn't transfer, maybe some bit of it will.
My point being though, unlike some purists, I like the technology race. It is much better than having a brand war simply on the basis of brand loyalty.
It's always interesting to see East Africans doing so well. Even with technology like advances in shoes and diet/training, genetics is still a huge factor.
Also it must be an crazy feeling to be Kejelcha, the guy who came in 2nd place. It would have been a world record, except for Sawe!
This is historic. To put this into perspective for people how to not follow running: This is about about as big as "derGrobe" beating the one-minute-mark in 4b2c.
Why not? People were not far from it and have been getting closer and closer to it for years. To me it seemed almost certain that it would happen this decade or next.
No asterisk needed. The criteria for record-eligible courses have been clearly defined. The weather was good, but not quite ideal. In slightly colder conditions I think Sawe could have gone a few seconds faster.
Yes. If sports does not happen in a vacuum then comparisons are unfair. If I go to the moon and break the record for long jumping should I be applauded?
Never thought I'd see the day ragebait made it to HN. Yes, let's pretend doing a long jump on the moon is comparable to running a marathon at its prescheduled time at its prescheduled location. Weather is always a factor in sports that take place outside. Might as well put asterisks on all accomplishments that took place on sunny days by your logic right?
Not sure I understand what you mean by "scientific." If you mean exactly reproducible, then almost nothing in athletics fits that definition. Every record in baseball, football, etc. would fail that definition.
I am impressed by your ability to delineate the weather effect on his run with such confidence! Particularly given advances in other variables that contribute.
Better weather has, to the best of my knowledge, never been part of marathon record keeping. People do note in accounts of (e.g.) the Boston marathon that the weather was particularly atrocious in some years (hence a general slow down across the field), but weather "aided" fast times are not considered illegitimate or even worthy of note.
Obviously, barring wind, which is why some marathon courses are not eligible for world records.
Human response to temperature shows significant variation. 50F/10C may be absolutely ideal for one runner, but a little too cold for another. That's why you can't unambiguously declare a given race to be "a good weather day".
By contrast, hail/rain and wind will negatively impact almost everyone, which is why talking about "a bad weather day" makes more sense.
That’s a wild reason to withhold a true record. People run marathons in all sorts of conditions since it became a thing. It is unlikely this is the best weather ever for a record set and even if it was, it’s never been a factor when deciding to qualify a record. That’s beyond unfair.
I just said it needs an asterisk, not withholding anything. What if someone runs one second slower in higher humidity and temperature. Now that I would applaud.
> I just said it needs an asterisk, not withholding anything
It’s essentially the same as not setting the record. It would be qualified every single time it’s mentioned and be functionally saying “…so it doesn’t count.”
Maurten spent months working with Sawe and other runners getting their gut capacity trained so they could absorb and burn 100 carbs per hour[0][1]
> The Maurten research team was embedded with Sawe’s team in Kenya for 32 days across six trips between last and this April. They were training his gut to absorb that load by mimicking race-day protocol in training. The hydrogel technology they have developed over the past 10 years now allows athletes to absorb 90–120 grams of carbs per hour without GI distress.
Second is the shoes. Adidas Adizero weigh 96 grams[2] with new foam tech and new carbon plates
Nike and INEOS spent millions over years to get Kipchoge to a sub-2 in artificial conditions, and now the elite end of the field are knocking that barrier out in race conditions. Unreal.
Running tech and training have been revolutionized in the past few years.
[0] https://marathonhandbook.com/sebastian-sawe-arrives-in-londo...
[1] https://www.instagram.com/p/DXmvAUvkWaq/
[2] https://www.runnersworld.com/uk/gear/shoes/a71129333/sabasti...
edit: correct :s/calories/carbs thanks
burning a hundred calories an hour is trivial. Most people will burn 100 calories per mile when walking or running, and more if moving as fast as these athletes, and many, many humans can do this for far, far longer than 2 hours.
It's the absorbtion that's the challenge. Maurten is not somehow alone in the particular stuff they've developed - ultra runners are generally shifting up into the 90-120 gram/hr range (or beyond!), using a variety of different companies' products. The gut training protocols for this are widely discussed in the world of running for almost any distance above a half marathon.
GP left out the units but is clearly talking about grams ("absorb ... 100 carbs per hour"), not calories (no one needs training to absorb 25g/hr). Carbs are 4 kcal/g. 100g of carb (400 kcal) an hour isn't replacement level for even casual athletic efforts, but it does mitigate the loss of glycogen in muscle somewhat.
> Even if you can absorb 120 grams per hour, it might not make you faster. In Podlogar’s study, cyclists burned more exogenous carbs when they consumed 120 rather than 90 grams per hour, but that didn’t reduce their rate of endogenous carb-burning—that is, they were still depleting the glycogen stores in their muscles just as quickly.
https://www.outsideonline.com/health/training-performance/en...
https://archive.ph/Vpk0h
https://pmc.ncbi.nlm.nih.gov/articles/PMC9560939/
Is that all the science to it?
So ~2800 calories of carbs with some fat being burned.
The race to tolerate lots of carbs is usually something you think of in 8 hour Ironmans. The good part is you can do most of it on the bike, which is much easier to eat as you go. As far as I know, many elite runners were doing like 50% water, 50% sports drink and consuming way under 100g.
This used to be true, and is still true for many athletes up the marathon distance. Above that, however, the momentum has swung heavily to very high carb intake. Most (though not all) of the world's best ultra runners (we're talking 7:00 min/mile pace through mountainous terrain) are picking this up, with many getting to and beyond 100g/hr of carb consumption.
It was confusing when the running industry switched from calories to grams of carbs, but that's all anyone talks about now.
"In the aerobic exercise domain up to ~100% of maximal oxygen uptake (VO2max), CHO is the dominant fuel, as CHO-based oxidative metabolism can be activated quickly, provide all of the fuel at high aerobic power outputs (> 85-90% VO2max) and is a more efficient fuel (kcal/L O2 used) when compared to fat."
https://www.gssiweb.org/sports-science-exchange/article/regu...
1 food calorie as listed on a food label is enough to heat 1kg of water by 1c
https://www.futilitycloset.com/2008/11/16/the-mensa-diet/
(If the nutritional calories in the drink had been only the same number of thermodynamic calories, the drink would have been energetically negative for the body because of its low temperature.)
But yeah, this is a thing. There is some gut distress for sure at higher levels of intake. See guy finishing second -- still under 2 hrs! immediately puking, which is fairly common at the high intakes. I've heard of Blumenfeld (the triathlete) taking like 200g/hr or more. Insane. Though he's had some epic GI disasters too, lol.
> Improved durability: Supercritical foaming produces a more consistent cell structure in a midsole. This should translate to pressure and weight being more evenly distributed, which should lead to greater durability of the midsole. “We’ve done a lot of testing of what foams look like on a dynamic impactor fresh versus 300 or 500 miles later, and we see less degradation in those materials longer-term,” FitzPatrick says.
> At least in terms of the midsole’s life span, super foams may have done away with the conventional benchmark that running shoes last about 300 miles. “I think it’s a dated standard,” Caprara of Brooks says. “It’s an easy go-to to help simplify. But every foam is different, and it’s not just the foam—it’s how it’s constructed, the shoe’s geometry, the rubber underneath it. There are so many factors. If I were to tell you the Glycerin Max lasts 300 miles, that’s probably less accurate than it is accurate. It’s probably closer to 500.”
https://www.runnersworld.com/gear/a64969945/secret-to-super-...
I’m sure someone will happily sell them to you if you enjoy wasting money.
The continental rubber outsole on these Adidas Adios Pro EVO 3 shoes are so thin (less than two sheets of paper, I think), that they don't even appear in side/profile views of the shoes. The outsole doesn't even extend the length of the entire shoe, it stops around the middle of the shoe. So heel strikers aren't welcome and will have loads of fun in wet weather. see https://www.adidas.com/us/adizero-adios-pro-evo-3/KH7678.htm...
In general, these high stack, forward-leaning shoes are meant for going straight ahead - imagine ladies' high heel shoes with an inch and a half of foam on the bottom - any sharp turns will force the runner to slow down or they'll twist their ankles. Looking at the London Marathon course, https://www.londonmarathonevents.co.uk/london-marathon/cours..., there's about twenty ninety-degree or sharper turns.
It's easier to draw attention (and therefore sponsorships) if you leave some room to improve on successive attempts. It's riskier to give everything up front and then risk plateauing or regressing in your subsequent attempts.
https://knowyourmeme.com/memes/bad-luck-brian
Super shoes. Most shoes have carbon plates in them now, they act as a spring, storing energy and propelling athletes forwards.
Better understanding of fuelling. Most athletes are taking between 100-120g carbs (sugar) per hour. Bicarbonate of soda has also been effective.
Better planning tools. Athletes look at elevation, headwind, tailwind and will plan a strategy around going harder into the hard stuff and knowing when they can back off and rest.
And to be honest, probably a metric tonne of PEDs (performance enhancing drugs) - unfortunately this is very common across all sports at the top level.
Note that Sawe funded extra testing drug testing for himself for the 2 months before winning the Berlin marathon. The testing followed Athletics Integrity Unit protocols (so surprise testing etc):
https://www.letsrun.com/news/2026/04/how-sabastian-sawe-conv...
This seems unlikely to be true, although it is repeated in every article I read about carbon plated shoes. The people that study them in a lab environment seem to disagree. See some of the papers here:
https://www.wouterhoogkamer.com/science2
However, I agree wholeheartedly with the overall points in your post!
I’m guessing like most things of this nature, you’re likely to have super-responders, responders and non-responders?
Also interestingly, the shoe in this record uses much less carbon than past shoes, both saving weight and allowing even more super foam where much of the energy return comes from. Though there so much variance in shoe design and materials there are only theories on how much comes from the plate vs foam vs stack height vs weight vs other factors.
I wonder where that leaves the barefoot movement. Hype dust?
If I'm going bouldering I absolutely cram my toes into a tiny rock climbing shoe, because it allows me to stand on ledges I couldn't without the extra support from the shoe.
That being said, if barefoot generally feels good to you and you're not chasing the pinacle of performance it's probably a perfectly fine choice for your recreational runs.
The carbon plate revolution is the main driver for drop in times over the last 5+ years
https://www.bbc.com/news/business-27335251
If this were a bodybuilding discussion, you would get advice on how to manage DOMS symptoms and how to plan your loading schedule, nobody would say that weightlifting "doesn't work" because a beginner got sore after lifting a 80kg barbell for the first time. But people has been conditioned to think that running is a purely cardio activity, so we don't talk about how the muscles and tendons in the foot need to be loaded up gradually just like your bicep.
Barefoot running is a weightlifting activity. Your calf muscle has to lift your entire bodyweight for the forefoot stride. "No pain no gain" applies. Proper posture and techniques are important. Proper workout schedule and loading plan with rest days are important. Sufficient protein intake are important.
Why is going harder in the hard stuff and easier in the easy stuff more efficient or faster than vice versa? I imagine arguments either way:
Going harder when it's easy gives you higher ROI. Or maybe going easier when it's hard is just too slow. And maybe that is too simplistic: Maybe it depends on how hard; that is, maybe there is a threshold.
https://news.adidas.com/sabastian-sawe---london-marathon/a/0...
In his marathon debut too.
I wouldn't have predicted this out of nowhere, but if you told me a marathon debut went this well and asked me to guess whose it was, I like to think I'd have come up with Kejelcha in my top few picks.
That said, great 5000/10000 athletes don't always have great marathon careers. An example from this race is the world record holder at both those distances, Joshua Cheptegei. He's run several marathons but none spectacular by his standards. He was in this race too but 7 minutes back.
Based on the quote below, next thing we will see is a "constructors championship" similar to F1 for winning shoe constructor in the 'major' marathons :-(.
" This dominance continued in 2024, with adidas athletes wearing Adizero models winning six out of 12 World Major Marathons – more than any other brand."
and yes, of course i race in super shoes :-).
There are age group leaders as well. That's perhaps a hundred people, of the tens of thousands running next to me.
Marathons are about running my own pace. The fact that there exists a world record is a piece of trivia.
Of course innovation in shoes will have a bigger marginal impact (because physics).
Three athletes broke the men's world record. One athlete broke the women's world record, and three were in the all time top 5. An Irish record was also broken, likely other countries too that I'm not familiar with.
Not to take anything away from the achievements. Incredible running.
Not so. She broke a record for a female-only-pacer marathon time. The women's world record was much, much faster.
However, because marathon are often mixed gender and the best male runners are significantly faster than the best female runners, it is possible for a woman to be paced from the gun to the tape by a male runner. For this reason, there are separate records for the women's marathon for women's only events.
[0] This is one of the things that made Kipchoge's original sub 2 result not record-eligible.
She broke the thing that the IAAF have gone back and forth on calling "the world record". It's the relevant record for this event - there was no more chance of her beating the man-paced record than of beating the men's record or the Le Mans lap record.
Very few mere mortals could run that fast for even 100m.
That works out to roughly a 16.7-second 100m. While certainly not crawling, that would be a fairly average pace for a fairly fit middle- to early-high-schooler with a bit of practice.
Yes that’s insane to maintain for a marathon, but it’s not even remotely out of reach for 100m for most relatively-fit people at some point in their lives.
At my peak, I finished the NYC Marathon in the top 2%. I still finished 45 minutes behind the winner.
It feels like elite athletes aren’t even competing in the same sport.
https://youtu.be/xkBmYQucyMs
https://www.athletic.net/team/770/track-and-field-outdoor/20...
* of course one mile is hardly comparable to the marathon that pros are able to sustain such speeds over...
https://www.athletic.net/TrackAndField/rankings/list/168546/...
That gives us 125k high schoolers in the USA who can break 04:30 for 1600m. There are about 18M high school students. So of just the high school population alone, about 0.7% of them can do this.
Assuming there are the 4x as many adults that can do this as there are high school students, that gives us slightly less than 0.2% of the total US population capable of this.
I rest my case.
Also bear in mind running a single mile under 4 mins was considered impossible for a long time.
It’s totally remarkable.
https://runrepeat.com/adidas-adizero-adios-pro-evo-3
The big improvement then was a carbon plate. Adidas (and others) followed suit. The subsequent improvements since then have been marginal but the margins are thin at that level. In this case the big advancement has been the weight of the shoe.
EDIT: Also it's worth noting these shoes are $500 retail. Adidas will for sure get a boost in sales from this, but there's definitely competition in the $200~$300 marathon running shoe space that won't solely draw everyone to Adidas)
I think the big story here may be the nutrition science to get these guys to absorb a lot of carbs during the run, more than the shoes.
Essentially the argument given was too much advantage came from the shoes and they didn't want racing to be about shoe technology development.
The advancements in shoes have made a measurable impact, but there are lots of optimizations being worked on.
But yeah at this point, “it’s the shoes, stupid” should defo be the main part of the conversation.
Or did the AI say we should be using PVA/cyanoacrylate/polyurethane glue or something?
Was there perfect conditions.or something?
Insane you could run 1:59:41 and not win!
Sabastian Sawe 1:59:30
Yomif Kejelcha 1:59:41
Jacob Kiplimo 2:00:28
The previous official record was Kelvin Kiptum's time of 2:00:35 in 2023. Eliud Kipchoge did 1:59:40 in 2019, but that wasn't record-eligible as it was held under controlled conditions. Source: The article.
It does sound like the course and the weather made it more likely to happen. And technical advances in shoe composition.
> The leading men went through halfway in 60 minutes and 29 seconds: fast but not exceptionally so. But it turned out that Sawe was merely warming up.
Between 30 and 35 kilometres, Sawe and Kejelcha ran a stunning 13:54 for 5km to see off Kiplimo. Yet, staggeringly, more was to come as the pair covered kilometres 35 to 40 in 13:42. To put this into context, that time is two seconds faster than the 5km parkrun world record, set by the Irish international Nick Griggs.
It was only after a 24th mile, run in 4:12, that Kejelcha wilted. But still Sawe kept going. Astonishingly, he crossed the line having run the second half in just over 59 minutes.
“Before 41 kilometres, I’m enjoying, I’m relaxed,” said Kejelcha, who had won silver over 10,000m at last year’s world championships.
“My body is all great. At exactly 41 kilometres, my body stopped. I tried to push, but my legs were done.
Sawe, though, powered on to set the fastest official marathon time in history. For good measure, it was also 10 seconds faster than Eliud Kipchoge’s unofficial 26.2 mile best, set in Vienna in 2019.
https://www.theguardian.com/sport/2026/apr/26/sabastian-sawe...
https://en.wikipedia.org/wiki/Kelvin_Kiptum
5km - 14:14 10km - 28:35 15km - 43:10 20km - 57:21 Half - 60:29 25km - 71:41 30km - 1:26:03 35km - 1:39:57 40km - 1:53:39 Finish - 1:59:30
Yomif Kejelcha also ran sub-two, clocking 1:59:41 on his debut marathon
You have to feel for Kejelcha - breaking 2h marathon and not even winning the race!
- https://www.mdpi.com/2813-0413/5/1/2
- https://pubmed.ncbi.nlm.nih.gov/29143929/
- https://sportrxiv.org/index.php/server/preprint/view/297
This is a nice video of the last 10 mins of the historic marathon race finish
https://www.youtube.com/watch?v=1voTDQQQf5g
London is a fast course. Let’s see what happens in Chicago and Berlin. If it was primarily tech that did it, we should see the record fall again.
Endurance sports are quite accessible and don't require that much time, effort, or talent to get way better than the vast majority of people, it's just consistency.
FWIW, that now includes me, as a 62 year old. I can hit 6:30 pace for 400m, but find it almost impossible to get under 10:0x for a mile. And that's even after 6 months of training for a 50 mile trail race.
It would be interesting to adjust this speed to account for the insane advancements in shoe technology over the last decade. Could it be as simple as measuring the delta in median marathon performance? Then look backwards to, say, 1996 and see what the technology-adjusted 2:00 mark is.
Sub-2hr marathon, beat the previous world record before Sunday, on your first try, and you don't win! Bad timing...
Prize money for London Marathon 2026 - https://www.thesun.co.uk/sport/38880592/london-marathon-2026...
Looks like first place male gets US$330K. Second place will get US$180K.
Divide by 2 to get the approximate hourly rate. :)
There's been lots of research into shoes though, so you might be able to work something out. For instance Jack Daniels (the running coach, not the beverage!) found that adding 100 grams to a running shoe increased aerobic effort by around 1%.
The popularity of running waxes and wanes - and the performance of the median runner varies with popularity.
Back in the 1980s the average half marathon finishing time was 1 hour 40 minutes - whereas today it's a little above 2 hours because there are a lot more people particpating.
Amazing these guys did it in a real race with no one in front of them (at the end at least)
I used to love F1 for the tech that would filter down to my car in ten years time, but that is not a thing anymore.
I for one love the advances in technology in something as supposedly simple as a shoe. And maybe I'll get to use it on a hike in a few years.
These shoes are practically disposable. They trade longevity for noticeable gains in performance. Even the tier below don’t last very long. This is not tech that is going to filter down to your hiking boots.
But the initial tech on an F1 car was not made for 200k miles either.
Even if the full tech stack to make it all work - material science, physical layout and construction - doesn't transfer, maybe some bit of it will.
My point being though, unlike some purists, I like the technology race. It is much better than having a brand war simply on the basis of brand loyalty.
Also it must be an crazy feeling to be Kejelcha, the guy who came in 2nd place. It would have been a world record, except for Sawe!
That's not me being sarcastic. I never, ever thought this would happen
Besides weather, there are loads of factors in the performance: shoes, clothes, food, etc. So basically every record gets an asterisk?
There is no rule for marathons.
https://link.springer.com/article/10.1007/s00421-010-1410-1
I thought there were scientists on here...
Don’t forget that two people actually ran under the two hour mark.
Obviously, barring wind, which is why some marathon courses are not eligible for world records.
https://worldathletics.org/records/certified-roadevents
It should be.
By contrast, hail/rain and wind will negatively impact almost everyone, which is why talking about "a bad weather day" makes more sense.
https://marathonhandbook.com/large-scale-marathon-study-iden...
I just said it needs an asterisk, not withholding anything. What if someone runs one second slower in higher humidity and temperature. Now that I would applaud.
It’s essentially the same as not setting the record. It would be qualified every single time it’s mentioned and be functionally saying “…so it doesn’t count.”
Edit: I was thinking in km/h and mixed it up. Sorry.