Miles was employed delivering groceries throughout the countryside by horse and wagon. To stay in shape he would run behind the wagon wearing heavy boots.
He had run through often-snowy hills along a streetcar line near his home for his distance training.
In April of 1926, Johnny Miles arrived at his first Boston Marathon having never competed in a race more than ten miles long. To prepare for Boston Miles ran more than a hundred miles per week, a level his father thought necessary to compete with the runners in the world’s most famous footrace.