SCIENCE OF ATHLETICS

The average healthy adult, asked to run as hard as they can for one mile, finishes in about 9 minutes. That same speed, you’d guess, is roughly what your body can sustain. Sabastian Sawe just ran 26 of those miles back to back, and each one took him 4 minutes 33 seconds. That is not jogging speed. That is sprint speed for most of us. He held it for 1 hour and 59 minutes and 30 seconds, and he was actually getting faster at the end.

Your body has three knobs that decide how fast you can run for a long time. The first is how much oxygen your lungs and heart can deliver to your muscles per minute. Scientists call this number VO2 max. A normal adult sits around 30 to 45. A fit recreational runner gets to 50 or 60. Elite marathoners are at 70-plus. Sawe’s is in that range. The interesting part isn’t the number itself, it’s what percentage of that ceiling he can hold for the full race. In a 2020 study of the 16 best male distance runners on earth (commissioned by Nike’s Breaking2 project), most were able to sustain about 92% of their max for two hours. Sawe ran London at roughly 99%. For two hours straight. Until last year, every textbook on endurance physiology said this was impossible.

The second knob is fuel. Your muscles run on sugar. The faster you run, the faster you burn it. Most trained marathoners can absorb 60 to 90 grams of carbs per hour during a race. Sawe trained his stomach over 12 months to take in 115 grams per hour, the upper limit of what a human gut has been measured to handle. The protocol came from a Swedish company called Maurten. Race morning, his pre-race meal was two slices of bread with honey and tea. During the race he drank a measured sports drink at 5km, 10km, 15km, switched to a caffeinated energy gel at 20km, and kept drinking every five kilometers after that.

The third knob is running economy. Two runners with identical lung capacity can finish a marathon five minutes apart because one of them wastes less oxygen with every step. Imagine two cars with the same engine but very different fuel economy. Average people use about 220 ml of oxygen per kilogram of body weight to cover one kilometer. Elite Kenyans use about 180. Less wobble, less braking, less wasted force, every stride. Sawe’s frame is 5’7” and roughly 130 lbs. Almost no upper-body muscle. Long, light legs. His coach Claudio Berardelli, who has trained Kenyan runners for 22 years, told NBC, “I thought I had seen pretty much everything. Then Sabastian started to show me something which I thought was almost impossible.”

Then there’s where he trains. The town of Iten in western Kenya sits at 7,900 feet of elevation. The air has about 25% less oxygen than at sea level. Roughly 1,000 elite athletes live and run there year-round, on red dirt tracks through forest, climbing 3,000 feet of vertical every week. The weekly schedule is the same for almost every camp: easy run Monday, track Tuesday, easy Wednesday, hills Thursday, easy Friday, long run Saturday, rest Sunday. Marathoners log over 150 kilometers a week. After a few months at 7,900 feet, the body grows extra red blood cells. When Sawe drops down to sea level for a race, his blood is carrying more oxygen per stroke than anyone he’s racing against who doesn’t train in the highlands. This is also why eight of the last ten marathon world records have been set by runners from Kenya or Ethiopia.

The closing kilometer of his race in London was the fastest closing kilometer ever recorded in a marathon. He covered the last 2.195 km in 5 minutes 51 seconds. That works out to a pace of about 4:17 per mile. After already running 24 miles. At 99% of his max. In 60-degree weather.

His coach said he hasn’t peaked yet. Eliud Kipchoge ran his fastest marathon at 37. Sawe is 31.