The Myth of the Lonely Long-Distance Runner
Lace up your sneakers and run around the block. Do that about 10 times and it's a mile. Do that…

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Lace up your sneakers and run around the block. Do that about 10 times and it's a mile. Do that 100 times and it's an ultramarathon. Now run those 100 miles up a mountain, or in the woods at night, or in a desert so hot that the soles of your shoes begin to melt.