What does it take to reach the peak of athletic performance and break barriers thought to be beyond human capabilities? One of these barriers is the two-hour marathon, a feat which requires running 26.2 miles while maintaining an average pace of 4:34 per mile. At that speed, you could run the 100-yard length of a football field in under 16 seconds! With improvements in training and exercise physiology, the men’s marathon world record has steadily decreased yet still lingers just above two hours. Some scientists believed the two-hour barrier would not be broken while others said it was only a matter of time.
Enter Eliud Kipchoge, the Kenyan long-distance runner who holds the world record for the fastest marathon after finishing the 2018 Berlin Marathon in 2:01:39. Winning 12 of the 13 marathons he entered, Kipchoge is widely regarded as the best marathoner of modern times. Kipchoge has a long history of success, including winning middle-distance championships in the early 2000’s and becoming the 2016 Olympic marathon champion. After falling short of a sub-two-hour marathon by only 26 seconds in Nike’s Breaking2 project, Kipchoge would again attempt to break the two-hour barrier at the Ineos 1:59 Challenge. But when every second counts, what would it take to allow the best of the best to approach the limits of human performance?
To improve running economy (how efficiently the body turns energy into running motion), Kipchoge wears a groundbreaking model of running shoes designed for marathoners. These lightweight shoes contain a carbon-fiber plate and a midsole with thick foam which ultimately lessen the energy needed to flex joints in the lower body, reducing overall demand for energy. The foam is also flexible and resilient; after a runner’s foot strikes the ground, the foam is able to push back (similar to a spring) to help propel the runner forward. Combined, these small running economy boosts can help shave seconds off Kipchoge’s pace.
To decrease wind resistance and ensure he keeps pace, Kipchoge is assisted by 42 world-class runners, including Olympic medalists. These pacers run in front of him in a V-formation, rotating in and out throughout the challenge. An electric car helps pacers maintain formation by projecting lasers onto the pavement. Periodically, a person on a bicycle provides Kipchoge with hydration and fuel in the form of a carbohydrate-rich drink mix, replacing water stations usually present in races.
Aside from training, fueling, and economy, there are a range of external factors which influence performance. A low-altitude environment with overcast conditions, minimal winds, and a temperature around 40-50°F set the stage for the best performances. High humidity and temperatures challenge the body’s ability to regulate temperature, raise lactate production, and ultimately decrease running efficiency. To optimize Kipchoge’s performance, event organizers narrow down locations, dates, and times until they find conditions sufficient for his next attempt.
On October 12th, 2019 in Vienna, Austria, temperatures ranged between 43-57°F with minimal rain, moderate humidity, and winds averaging about 5 mph. This location was under three hours from where Kipchoge lived (reducing jet lag) and at a low altitude, facilitating a higher concentration of oxygen in the air. Here, Kipchoge would attempt a sub two-hour marathon by competing 4.4 laps around a flat, tree-shaded course consisting of two long stretches with small loops at each end. That morning, Kipchoge started off strong, maintaining a consistent speed aided by the pacers smoothly rotating in and out along the course. Reaching the halfway point 10 seconds ahead of pace, Kipchoge and the pacers steadily progressed. With just over half a mile to go, the pacers were waved off and Kipchoge accelerated down the final stretch. Waving to the crowd and pumping his chest, he crossed the finish, completing the 26.2 mile course in a breathtaking 1:59:40.
While he shattered the two-hour barrier, Kipchoge’s time does not count as a marathon world record as event conditions did not meet official standards. The Ineos 1:59 Challenge was not an open event, Kipchoge was led by rotating pacers and a pace car, and he was handed fluids by cyclers. Yet, he is still recognized as the first human to run the marathon distance in under two hours. So what is next for breakthroughs in the marathon? Thirty years ago, scientists predicted an ideal athlete in perfect conditions could run a marathon in 1:57:58. In a marathon compliant with world record criteria, is this possible? As Kipchoge stated in an interview following his sub-two-hour marathon run, “Personally, I don’t believe in limits.”