Kardong graduated from prestigious college-prep school, Seattle Prep in 1967, earned a bachelor's degree in psychology from Stanford University in 1971, and, in 1974, another bachelor's degree in English and a teaching certificate from the University of Washington. He then taught school in Spokane, Washington, from 1974-1977 at Loma Vista Elementary. From 1977 to 1986, Kardong owned and operated a retail running store in Spokane. In 1977, Kardong founded the Lilac Bloomsday Run 12K.
As a journalist and author, Kardong was a contributing editor for Running magazine from 1980 to 1983, and a contributing editor (1983–1985) and senior writer (1985–1987) for The Runner magazine. Since 1987, Kardong has been a contributing writer for Runner's World magazine.
Kardong was president of the Road Runners Club of America from 1996 to 2000. He served as executive director of the Children’s Museum of Spokane from 2002 to 2004, and as race director of the Bloomsday run since then.