Born in Halifax, West Yorkshire, as a child he moved with his family to Florence, Nova Scotia, a coal town located near Sydney Mines on Cape Breton Island.

When his father enlisted in the armed forces in 1916, at age 11 he helped to support his family by working in the coal mines during the evening shift and continuing at school during daytime.

[2] As a young man, Miles worked various temporary jobs, including a stint in northern Ontario.

The field at the 1926 Boston Marathon included four-time winner Clarence DeMar and 1924 Olympic champion Albin Stenroos, whom Miles idolized.

Miles arrived at the marathon as an unknown, competing in a handmade singlet adorned with a maple leaf and the letters "NS" for Nova Scotia and a pair of 98-cent sneakers.

Miles attempted to defend his title at the 1927 Boston Marathon, but dropped out early due to problems with his shoes.

He had moved to Hamilton, Ontario in 1927 and, while training for the 1928 Olympics, he found work as a labourer for International Harvester.