Inside London 2026’s Sub 2 Hour Marathon

Duncan Koehn MS | May 2026

The 2026 edition of the London Marathon was a particularly exciting moment for endurance sport. The two-hour barrier has been the rabbit of the elite running community for many years, with programs like Nike’s Breaking2 pulling out all the stops to bridge the gap.  Then, in a single morning, that magic barrier fell not once but twice!

Kenya’s Sabastian Sawe delivered the first officially recognized sub-two-hour marathon in 1:59:30, with Yomif Kejelcha following just seconds behind in 1:59:41. As two runners break this record, many are asking what changed to make this possible, whether sub 2 will be the new standard, and how us normal mortals can use the factors that made these incredible performances possible.  A number of factors contributed to this record, including a convergence of talent, ideal conditions, technological advances, and fueling and training breakthroughs.

• London 2026 had one of the deepest fields of elite runners at a marathon major in history; multiple runners had flirted with the world record on an individual basis.  This contributed to a unique race dynamic with a consistently high pace throughout the race, particularly in the last 10km.  Competition provided the motivation for this high pace, allowing athletes to dig deep and avoid relying on outside pacers.

• Conditions for London 2026 were just about as ideal as possible to set a world record. The London course itself contributes to a fast race with a flat profile with few technical turns and consistent road surfaces.  In 2026, mild temperatures, low wind and even pacing combined with the course factors to allow the athlete to operate at very close to their theoretical limit.

• Technology has long been the race behind the race in the running world.  In 2026, super shoes are better than they have ever been with shoes such as the winning Adidas Adizero Adios Pro Evo 3 increasing efficiency by 1-3%.  The lower leg and foot are not idealized for running efficiency, making this mechanical assistance an additional source of the marginal gain that makes these records possible.

• Endurance training has improved even compared to the training strategies used 5 years ago.  Generally, athletes are training at higher volumes due to improved recovery protocols, allowing for improved adaptations.  Advances in monitoring and testing, such as lactate and metabolic testing, heart rate and heart rate variability metrics, as well as biomechanical feedback from running analysis and training, have allowed programs to become more individualized than ever.  

• Fueling strategies in endurance sports have also undergone an evolution in recent years.  Athletes have increased carbohydrate intake while racing to keep fuel stores topped off while using buffers to allow for increased exercise intensity. Based on fueling data released by top racers, many athletes were onboarding an average of 115 grams of carbs per hour, generally in a form containing a bicarbonate buffer.  Because this is on the high end for carbohydrate consumption, the elite marathoners also trained their guts to handle the fueling without GI distress.

While on their own, each of these factors seems small, combined, they do lead to large performance benefits in both pros and amateur athletes.   Experts say the theoretical limit for a marathon record is likely in the 1:40 to 1:45 range. I’m excited to see the progression in performance now that the 2-hour barrier has been broken.

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