The race against limits: Why marathon runners keep getting faster
History was made at the 2026 London Marathon when Sabastian Sawe became the first person to run an official marathon in less than two hours.
The Kenyan recorded a world record time of 1:59:30 (pending ratification) on a day where Ethiopia’s Yomif Kejelcha also completed the race in sub-two hours, making it home 11 seconds after Sawe.
With this, the trend of world record-breaking marathons continued.
Sawe knocked over a minute off the previous record time (2:00:35), set by Kelvin Kiptum at the 2023 Chicago Marathon.
Rewind a decade and that record was almost three minutes slower; Wilson Kipsang – another Kenyan – delivered a record-breaking 2:03:23 run in Berlin in 2013.
But why are runners getting quicker? How do records continue to be obliterated?
One of the primary reasons for this evolution is carbon fibre-plated shoes – a lightweight shoe which uses carbon fibre plates and high rebound foam to reduce fatigue and energy loss.
German athlete Johannes Motschmann said: “They allow for more training and quicker recovery, and of course, faster times during races, especially at longer events.
“They are very important and make a huge difference in training and racing.”
These shoes were first produced by Nike in 2016 and have since changed the game for elite long-distance runners.
Major marathons across the globe began to be dominated by runners wearing these so-called ‘super shoes’.
Kiptum wore a prototype of the Nike Alphafly Next% 3 shoe when he set the record in 2023. And in London last month, Sawe wore the Pro Evo 3 from Adidas.
“The foams have continued to improve and extend running careers,” said Camille Herron – an American ultramarathon runner who holds 12 world records.
“I’m 44 now and my body feels better now than it did five to 10 years ago. I put on the shoes that I wore back then and it blows my mind, how much better they are now!”
Richard Whitehead MBE – a two-time Paralympic gold medalist and holder of the world record for Fastest Double Amputee Marathon – said: “They’ve transformed a lot of international runners into world class athletes and a lot of recreational runners are getting towards that sub-three hour marathon time.
“They’re specifically made for running a marathon, like the top ones that are £400/£500 are literally built for one race. So if somebody’s built that for one race, then clearly it’s offering some kind of advantage.”
But these ‘super shoes’ aren’t without controversy, with many calling for the record books to distinguish between those set before the shoes were used by the masses and those after.
Following accusations of technology doping at the 2020 Olympics, World Athletics changed their guidelines. The shoes now have a maximum stack height of 40mm.
When it comes to race day, runners do all they can to put themselves in the best possible position. But shoes are just one factor in this wider debate.
“Competition is a big factor,” explains Whitehead. “So if you’ve got a lot of people chasing a target, e.g, the sub-two hours for men, it becomes something that there’s a lot of appetite for.
“There’s a real onus on being the first. London will always be the race that officially saw a man run under two hours, and that’s a tag they’ll have forever.”
In the 1970s, recreational running became a widely practised hobby. In the decades since it has only exploded in popularity, and that effect has also been carried across to the elite level, especially in long-distance running.
Ultramarathon event participation has grown by 345% in the last decade. Meanwhile, the London Marathon received a record 1.3 million applications for its 2027 event.
“Several years ago there were discussions about why there were so many more Japanese and international runners breaking ~2:06 in the marathon, yet fewer American runners doing it,” recalls Herron.
“I think Americans have finally broken through and it’s probably because of the shoes, nutrition/knowledge, and also more coaches and medical support. There’s more support all around elevating athletes, and social media is also so powerful in how we inspire each other.
“If you have more people doing a sport, you’re naturally going to see faster times all around.”
With sport science, technology, and data all having improved tenfold in recent times, runners have never been in a better position when it comes to preparing for races.
But there’s some things that athletes can’t always prepare for.
“There’s always an element of luck around getting a world record,” explains Whitehead. “You’ve got to have other things in your favour.
“You’ve got to have good weather conditions and the athletes themselves need to wake up feeling 100% as well because it’s obviously a real investment in energy to run that fast.”
Training conditions are clearly a huge factor, and some parts of the globe are better equipped than others. Seven of the last nine marathon world records set by men have been set by Kenyans.
“They [Kenyans] run so many miles anyway. Their training weeks are so intense that they’re able to bang out a marathon,” says the Paralympian.
“Then they’re running after to cool down when everybody else is really struggling to walk!”
Marathon records are being broken not only in the men’s side of the sport, but also in the women’s.
The 2026 London Marathon also saw Ethiopia’s Tigst Assefa break the world record she set at the same event a year earlier, completing the race in 2:15:41 (pending ratification).
Britain’s Paula Radcliffe broke the world record three times and held it for 12 years from 2005 to 2017, when Kenya’s Mary Jepkosgei Keitany chopped 41 seconds off that time (2:17:01).
In almost a decade since, that record has been broken a further six times.
“I think women are definitely racing more aggressively and confidently now,” explains ultramarathon legend Herron. “I was doing it five to 10 years ago and usually racing alone with the men.
“Now there’s more women capable of keeping up or exceeding my records. Iron sharpens iron, and it’s great to see women racing with more confidence and self-belief.”
Humans continue to push their bodies to the limits of what is possible. Long-distance running feats are only getting more impressive, but just how far these athletes can go remains to be seen.
“I would say the technology might now start to transfer from the road onto the track,” Whitehead hypothesises. “And we might get really close to the world records on the track.
“But when these manufacturers are pumping millions of pounds into research, that’s when you’ve got to say, actually they must feel that those records can be broken.”
