How Sebastian Sawe Broke the 2-Hour Marathon Barrier at the 2026 London Marathon

Sawe’s Elite Physiology 

Elite performance demands elite physiology. Not built on a single physiological trait but instead the complex interaction between multiple variables. Whilst Sebastian Sawe undoubtedly possesses an elite VO2peak, this alone doesn't completely explain this record breaking performance. 

Understanding Lactate Threshold 2 (LT2; sometimes termed ‘anaerobic threshold’), the defining variable in endurance performance, provides further insight into the exceptional physiology behind these incredible athletes. LT2 represents the threshold where intensity sits just below the rapid onset of blood lactate accumulation, and in the world's best endurance athletes this sits remarkably close to their VO2peak.  

Research led by Andy Jones in 2020, as part of the Nike Breaking2 project highlighted just how elite these adaptations are. To break the two hour barrier, it was estimated that athletes would need to sustain close to 94% of VO2peak - operating extremely close to their physiological ceiling for the duration of the race. 

Equally important is an excellent running economy - the oxygen cost of maintaining a given pace. The very best athletes have an exceptionally low oxygen cost dipping below <185 ml/kg/km. Pair this with an LT2 at 92-94% of VO2peak and a VO2peak >75 ml/kg/min and you get an exceptionally rare physiological profile, even amongst elite athletes  - capable of maintaining 2:50/km for 42.2 km. 

At the elite level , it's not just about having a big engine, it's about how efficiently you can get close to its limits without it completely breaking down.  

250 km Per Week?

Freak performances like this don’t just happen by accident. Way before the headlines, state of the art shoes and perfectly timed nutrition, the foundation is built through months, if not years, of brutally consistent training. 

For athletes like Sawe, weekly mileage often sits around 200-250 kilometres per week. Whilst this number seems incomprehensible, and simply put it is - it's not just about stacking empty miles. It’s about how that volume is structured. 

A large proportion of Sawe’s running is done well below his first Lactate Threshold (LT1; sounds termed ‘aerobic threshold’), at an easy conversational pace. This isn't just junk mileage; it’s volume strategically used to develop elite aerobic conditioning, improving mitochondrial density, capillary density and running efficiency without excessive fatigue accumulation. 

Within this volume a number of key sessions are used to truly define marathon success.

Notably, Sawe has two critical 40 km long runs before race day, performed at or around race effort. Although these sessions are about physiology, strategy also plays a key role. Running at race effort, specifically conditions the body to maintain a high % of VO2peak , whilst providing a perfect opportunity to practice in-race fuelling - dialling carbohydrate intake, fluid intake and gut tolerance. 

Alongside this, Sawe incorporated longer interval efforts, often 10km+, at faster than race pace. These sessions are specifically designed to ‘move the needle’, raising the physiological ceiling by shifting LT2, improving lactate clearance, in turn making marathon pace more manageable.

From this emerges a training model built on contrast - a large volume of low intensity aerobic work, interspersed with race pace familiarisation and high intensity interval sessions designed to push physiological limits. 

It’s this perfect balance, as opposed to one “hero session” that allows athletes to arrive primed, ready and capable of sustaining 2:50/km for over 42 km.

Toast, Honey and Tea

When all the hard miles are complete and the engine is built, the focus then shifts to providing the engine with enough fuel to perform. This all starts with an excellent carb load in the 48-72 hours leading up to race day and culminates in a well-designed pre-race breakfast. 

Two slices of toast with honey and tea before one of the greatest sporting achievements of all time; surely not?

No large meal, no aesthetically pleasing bowl of oats. Sawe kept it simple, easy-to-digest and trusted his carb load.

In the hours leading up to the race all the hard work is done, muscle glycogen is saturated and the body is primed for performance. Here a simple pre-workout meal, keeps liver glycogen topped up, where surprisingly toast, honey and tea is the perfect combination*. 

*We should note that he also sipped on an energy drink (Maurten Drink Mix 320) on the bus ride over to the race, in addition to an energy gel minutes before the gun. 

A Maurten Masterclass

When the physiology is maxed out and the carb load is complete it all comes down to race day execution - this is where Sawe and his team separated themselves from the rest.  This wasn't just fuelling, this was a performance nutrition masterclass.

In the lead up to race day Sawe wasn’t just logging miles,  he was dialling in his fuelling strategy. From February 2025 to April 2026 experts at Maurten spent 32 days total with Sawe conducting a battery of tests, with perhaps the most significant of these being a CHO utilisation test. This is where performance nutrition is heading, not only generic plans and recommendations (e.g. 90g/h or 30g every 30 mins), but individualised strategies backed by informed lab testing. 

By race day everything was dialled in. 

Sawe targeted an incredible 115 g/h during the race - well into elite fuelling territory. The use of a multiple transportable CHO system (1:0.8 Glucose: Fructose) allowed greater exogenous CHO oxidation. In simple terms, he wasn't just consuming more fuel but he had the ability to utilise it to improve his efficiency at race pace. 

The strategy was simple, the execution was flawless:

• 1 x Maurten Gel 100 (25g CHO) 5 minutes before the race start 
• 160ml of Maurten 320 Drink mix every 5 km (26g CHO per serving)
• Additional Maurten Gel 100 Caff 100 at 20 km (25g CHO, 100 mg Caffeine)

Like the rest of Sawe’s plan the caffeine timing was perfect, taken at 20 km it would peak towards the end of the race, where fatigue was building and it’s not implausible to think that extra boost could have helped him to pull away to take the win. 

The 40 km Aid Station 

Here’s the detail that defines elite execution - Sawe fuelled at 40km.

At this point most athletes would rely on what's left in the tank and suffer through the closing km. Sawe didn’t, he saw this an opportunity to stay topped up, maintain blood glucose and make a race defining move. 

Despite his exceptional debut performance, Yomif Kejelcha missed fuelling opportunities at 5 km and 40 km. When spending two hours close to your physiological ceiling it's not just about how much fuel you take on but when you take it. At this level these details matter. 

When it came down to it, Sawe didn’t just have the most efficient engine. He fuelled it better than anyone else. 

The Shoes

When discussing the backdrop to any new running world record, often at the forefront of the conversation is the athlete's choice of shoe, a factor that can’t be ignored. Competition between brands to produce the next breakthrough in performance technology has never been greater. Research published in 2018 suggested that a prototype Nike shoe reduced the energetic cost of running by up to 4%, helping fuel the belief that shoe technology would be key in eventually breaking the sub 2hr marathon barrier. 

At the 2026 London Marathon however, it was Adidas athletes who stole the show. 

Weighing a staggering 97g the Adidas Pro Evo 3 was the shoe of choice for the top two athletes. This super shoe has been designed to minimise energy cost at race pace by combining an ultra light upper, lightstrike pro evo midsole and a carbon infused ENERGYRIM.  Effectively this shoe gave Sawe more bounce with less effort.  When the race pace is 2:50/km even a 1-2% improvement in running economy translates into meaningful energy savings over 42.2 km.