After he was defeated by Joseph Guillemot in the 5,000 metres at the 1920 Antwerp Olympics, Nurmi rethought all aspects of his daily routine.
He concluded he had demonstrated faulty pace judgment and started training and even competing with a stopwatch in his hand.
More significantly he based his training on long, slow distance work to provide stamina, a programme rediscovered in the 1960s. Nurmi also experimented with interval training, a succession of timed runs over the same distance.
The results were astonishing.
The Finn, whose statue stands outside the Olympic stadium in Helsinki, won nine gold and three Olympic silver medals and set 29 world records between 1920 and 1932.
His performance at the 1924 Paris Games has become the stuff of legend.
OBSESSIVE
The finals of the 1,500 and 5,000 were scheduled within half an hour of each other, adding a further 25 minutes after a Finnish protest.
Nurmi took a 30-metre lead in the 1,500, before slowing in the final lap. He still set an Olympic record of three minutes 53.6 seconds.
In the longer event he saw off compatriot Ville Ritola, winning in another Olympic record of 14:31.2.
On the following day the remarkable Nurmi won another gold in the 10,000 metres cross country, a discontinued event, at the peak of a Paris heatwave in which temperatures touched 35
Part of Nurmi's obsessive temperament can be traced to his background. He was born into poverty in the former Finnish capital of Turku in 1897 and forced to quit school at the age of 12 and work as an errand runner.
Running through the pine forests proved a salvation, mentally, physically and finally financially.
Constant rumours that Nurmi was infringing the strict amateurism rules of the day came to nothing until the 1932 Los Angeles Games when he planned to run the only Olympic distance he had never entered, the marathon.
By this stage the IAAF had enough evidence to prevent Nurmi running in Los Angeles and the taciturn Finn went into seclusion, albeit while continuing to make money by shrewd real estate investments.
Nurmi made a surprise appearance at the 1952 Helsinki Games, carrying the Olympic torch on the final lap.
Even the Soviet team, competing for the first time since the 1917 Russian Revolution, broke ranks to applaud as he handed the torch to Hannes Kolehmainen to light the flame.