When Sebastian Sawe broke the two-hour barrier at the London marathon, it triggered questions of how much technology and science had contributed to the feat. But there's a lot more to it than just a US$500 super-shoe and advanced fuelling to fight muscle fatigue, writes Maxwell Muttai, a sports PhD researcher at Loughborough University, investigating performance optimization in footwear.
In the last week, numerous sceptics have come up to discredit the record-breaking and history-defining performance made in the London Marathon by not only the winner, but the whole podium, who all broke the previous World record set by the late Kelvin Kiptum. The argument has two main elements: the footwear (engineering) and carbohydrate fuelling intake (science).
The first element is a perspective that has been presented numerous times since the beginning of the super-shoe era, marked by the release of the Nike Vaporfly 4% in June 2017. This shoe was the first shoe to feature a carbon-plate, and compliant and resilient foam, all while being lightweight. These features were studied to reduce running economy, a measure of how much oxygen a runner is consuming per minute, by 3-4% (hence the name Vaporfly 4%).
It made its mark on the marathon stage when Eliud Kipchoge crossed the finish line at the 2018 Berlin marathon, breaking the world record at the time with the clock reading 2:01:39, and a month later by Abraham Kiptum, setting the then half-marathon world record (58:18). The records set by this evolutionary technology kickstarted an arms race between footwear companies, who all aimed to create the shoe that would break the 2hr marathon barrier.
A week ago and almost ten years later, Adidas released the Adizero Adios Pro Evo 3, the third generation of their Pro Evo race-day shoe series. A day later, it broke a world record three times. ?
The Nike shoe weighed 185 grams, an incredible mass at the time, while returning 85% of the energy placed on it when the runner’s foot touches the ground. The shoe’s midsole height was 31mm and had a full carbon plate running the length of the shoe, which was inserted in the midsole to increase energy return in the shoe. The Adizero shoe has more energy-returning material on the midsole, with a midsole height of 39mm. This means even less energy is lost per step when running on the adidas shoe.
Weight, and Fuel
The amazing part of the shoe? It weighs 97 grams! For context, this is less than a banana and more importantly, almost 50% less than the Nike shoe. How Adidas managed to return more energy to the runner and add more midsole material, while reducing the mass of the shoe to the lowest any running shoe has ever been, is a mystery testament to investment in their R&D.
One may ask, how does reducing almost 100 grams in a shoe help? Numerous studies have shown an increase in 100g of shoe mass induces a 1% increase in energy consumed by the runner, which translates to ~72 seconds over a marathon distance. Cut off the weight? Cut your time by an almost equivalent fraction. And the price of the shoe? US$ 500
The second target for sceptics is the fuelling strategy. For decades, sports scientists believed that marathon fatigue was primarily driven by muscle glycogen depletion, which is the expenditure of energy stores within the muscle fibres. When this glycogen runs out, blood glucose falls below a lower threshold, causing the brain to reduce its signals to the muscles and making the runner hit a ‘wall’.
The runner slows down because the muscles have run dry. To counter this, the runner can consume carbohydrates during the race, preventing a fall in blood glucose and ensuring the lower threshold is not passed. Even with 10g/h of carbohydrate intake, time to exhaustion has been seen to increase by 12-20%.
For Sawe’s case, an infographic shared by his nutrition partner showed that he had an average carbohydrate (CHO) intake of 115 grams per hour across the race, a figure that approaches the upper limit of fuelling proposed by numerous studies, of 120g/hr.
Could Sawe Have Done it Without the Tech?
Now, for the argument, would Sawe have beat the 2-hr barrier without the above technology, and all sports science advice from his teams? Definitely not. However, this claim implies that there was once a purer era, where athletic achievement was completely unmediated by technology. There was not. The evolution of sport and the evolution of science/engineering are both intertwined.
What technology does in every era is raise the floor; it makes the best performance of one generation look like the lower threshold of the next. So yes, everything is better; shoes, nutrition, pacing, monetary motivation and coaching science, all unavailable to previous generations. However, every generation competes with the tools available to it, and every generation’s records reflect those tools. That is not meant to be scandalous.
The reason Sawe broke the two hour barrier is that he is already one of the finest distance runners in history-he has never lost a marathon-, and that he ran the race of his life. In fact, odds are that he will break his 1:59:30 record in his career. And yes, today’s engineering and science will give him the best possible platform, but the years of weekly 200-kilometre training in high altitude, fitness, pain tolerance and tactical intelligence do not come in a shining US$500 shoe box with an energy drink.
No one can take anything away; what Sawe builds on today’s tech platform is entirely his own, and of those capable of challenging him.
