Paavo Nurmi approached athletics like a science experiment. For three decades, he tested and toggled his running to become the swiftest, most efficient human the world had ever seen. 

He began at ten years old and joined a track club. He trained with other kids three or four times a week, covering four to six kilometers in the Finnish forests. After a year or so he could run fifteen hundred meters in five minutes. This made him a good, but not great runner, so he sought to change his running. 

He wrote to Hannes Kolehmainen, who had just won three gold medals at the Stockholm Olympics. At Holehmainen’s recommendation, teenage Paavo began training twice a day— walking in the morning and sprinting in the evening. This made him a better, but still not great runner, so he sought to change his running. 

He joined the military and so impressed officers with his toughness that they assigned him easier duties to allow time for training. He tested new training methods— holding on to trains as they passed to increase his speed and open up his stride, running in iron-clad boots and fifty pound sacks of sand, he even started training through the winter, a rare commitment in Finland. 

This made him a great runner, at least in Finland. He set personal bests at every distance, even setting a national record in the three thousand meters. He won two races at the Finnish Olympic Trials in 1920 and hopped on a train to Antwerp. 

In the Olympic 5000m final, Paavo Nurmi set off at world-record pace before getting kicked down in the final stretch by a Frenchman named Josef Guillemot. Furious— though he won a silver medal and set a personal best by thirty seconds— Nurmi sought to change his tactics. In the 10000m final, he ran in the back of the pack, spreading his efforts evenly, before kicking down Josef Guillemot in the final stretch and winning his first gold medal. He won his second and third days later in the cross country race both individually and as a team. 

Despite three gold medals, the 5000m defeat still rankled. A great runner could still get out kicked in the homestretch, but the greatest runner could win anything regardless of tactics, so Nurmi sought to change his training further. He began running with a stop watch clutched in his fist, developing a robotic inner metronome that allowed him to objectively decide how quick to run despite any discomfort. In 1921 he set a world record over ten thousand meters. In 1922 he set world records in the two, three, and five thousand meters. 

In 1923, Paavo Nurmi decided to approach the mile world record scientifically. He scheduled a race against Edvin Wide, the fastest Swedish miler, over a 385 meter track in Stockholm. Nurmi marked out his own 385 meter track in Finland and began running his afternoon speed sessions just faster than world record pace. In the lead up to the race, Nurmi told the press “I’ll run 4:10. If Wide runs faster, he’ll win.” Nurmi ran 4:10. Wide didn’t run faster. Paavo Nurmi now held every world record from the mile to the 10000m, a feat never before or since replicated. 

In 1924, the International Olympic Committee decided that they couldn’t let Paavo Nurmi win everything in the Paris Games, so they scheduled the 1500m and 5000m final forty five minutes apart. Nurmi responded by changing his training: he added a third session of cross country running to his evenings. In a dress-rehearsal for the Olympics, Nurmi broke the world record for the 1500m, then forty five minutes later he broke the world record for the 5000m. In the Olympics themselves, Nurmi won gold in both events, running only a few seconds slower. He also won the cross country race, as did the Finnish team, and the 3000m team race, bringing Nurmi’s gold medal count to eight.

The Finnish Olympic Committee forbade Nurmi from competing in the 10000m in Paris— this allowed Nurmi’s countryman Ville Ritolla to win a gold medal of his own and set a world record. Nurmi, in response, ran an unofficial ten thousand meters on his own on a practice track at the same time as the event and unofficially finished thirty seconds before Ritolla. A month later, Nurmi ran an official ten thousand meters and officially retook the world record from Ritolla. 

In 1925 Nurmi sailed to America and ran fifty five races over five months and won all but the last one, an 800m race in Yankee Stadium. In 1928 he beat Ritolla for a gold medal in the 10000m but lost to Ritolla for a silver medal in the 5000m. Suddenly vincible, Nurmi sought to change his training— he focused on longer distances, adding a 30km run to his weekly routine. He set world records for the fifteen kilometer, ten mile and one hour run all in the same race. 

He planned, in 1932, to finish his career like his idol Kolehmainen: with a gold medal in the Olympic marathon. He won the Finnish Olympic Trials by over six minutes, setting a world best for 25 miles. Upon landing in Los Angeles, however, he learned that the international Olympic Committee had barred him for “professionalism” after he accepted excessive travel expenses. Nurmi sailed back to Finland, ran for another two years then retired, utterly undefeated over ten thousand meters and having finished lower than third only three times in his career. 

Paavo Nurmi’s science experiment successfully sculpted him into the greatest runner of all time. His training evolved empirically, from running three times a week to three times a day, from simple lopes over cross country courses to morning walks, afternoon sprints, and evening jogs. He trained specifically, checking a stopwatch to perfect his pacing, adjusting his speeds to his goals, and the length and frequency of his sessions to the length and frequency of his races. He influenced generations of runners to come— Emily Zatopek admitted to tearing through the streets as a child shouting “I am Nurmi! I am Nurmi!”

Every Finn, enduring grueling, unforgiving winters, understands that success requires grueling, unforgiving work— their culture fosters successful endurance athletes. Nurmi, however, desiring more than simply success as an endurance athlete, pioneered scientific training methods that fostered greatness