“The difference between a jogger and a runner is an entry blank” is a much-quoted statement from Brooklyn-born Dr. George A. Sheehan (1918-1993), a writer for Runner’s World from 1970 and the author of many books on the sport. “To me, the essential difference between a jogger and a runner was not ability or training; it was an entry blank,” Sheehan wrote in Runner’s World in 1977 and in the book George Sheehan on Running to Win (1992). Sheehan believed that racing and becoming a competitive athlete was the true reason for running.
 
   
Wikipedia: George A. Sheehan
Dr. George A. Sheehan (November 5, 1918 - November 1, 1993) was born in Brooklyn, New York. He is best known for his books and writings about the sport of running. His book, “Running & Being: The Total Experience,” became a New York Times best seller. He was a track star in college, and later became a cardiologist like his father. He served as a doctor in the United States Navy in the South Pacific during World War II on the destroyer USS Daly (DD-519). He married Mary Jane Fleming and they raised twelve children. He continued to write while struggling with prostate cancer. His last book, Going the Distance, was published shortly after his death.
 
16 September 1979, New York (NY) Times, “A Doctor on the Run” by Sandra Cummings, New Jersey Weekly, pg. NJ120:
“An entry blank” separates runners from joggers, of whom he (Dr. George Sheehan—ed.) says: “It’s a shame they have not made the leap into competition.”
     
Google News Archive
30 November 1983, Mid-Cities Daily News (Hurst, Euless, Bedford, Richland Hills, Halthom City, Watauga, TX), “Running: Sheehan and Fixx will direct fitness festival” by John R. Stiles, pg. 8A, col. 3:
DR. SHEEHAN also has the best answer I’ve heard yet for the age old question about the difference between a “jogger” and a “runner.”
 
“The only difference between a jogger and a runner,” says Sheehan, “is a race entry blank.”
 
Google News Archive
12 September 1986, The Blade (Toledo, OH), “Fitness” by Dr. George Sheehan, pg. 12, col. 5:
The difference between a jogger and a runner is an entry blank.
 
11 October 1987, Star-Tribune (Minneapolis-St. Paul, MN), “Doctor-turned-marathoner offers thoughts on the run”:
Why do they do it, those 6,700 runners of all sizes, shapes and abilities who will pound the pavement for 26.2 miles this morning in the Twin Cities Marathon?
 
To get the answer, one might listen to Dr. George Sheehan, the noted marathon runner, author, physician and philosopher from Red Bank, N.J. He doesn’t mince words when speaking on his favorite subject.
(...)
In an interview yesterday, Sheehan said that “the difference between a jogger and a runner is an entry blank. One race and you’re hooked.”
 
Google Books
George Sheehan on Running to Win:
How to achieve the physical, mental & spiritual victories of running
By George Sheehan
Emmaus, PA: Rodale Press; New York, NY: Distributed in the book trade by St. Martin’s Press
1992
Pg. 16:
To me, the essential difference between a jogger and a runner was not ability or training; it was an entry blank. After all, I know joggers who train longer and can run faster than runners who compete. It is the attitude, the perception of self, the need for a different expression that leads the jogger to fill out that first entry blank and take the giant step into competition.
 
Now I’m not so sure about that definition. The jogger who goes into races becomes a competitor, not a runner. The jogger has merely become a racer, a change that may be more sidewise than forward in progressing toward the goal of becoming a runner.
 
The jogger and the racer are in many ways quite alike. If the jogger is the runner in embryo, so is the racer. If a jogger is a novice, so is the racer. For each, the growth is at first in ability.
(Also from Runner’s World, volume 12, 1977, page 23—ed.)
   
Bald Runner
Remembering George Sheehan
Runner, Writer Explored the “Why”
Published November 02, 1998, in The Post-Standard.
By Dr Kamal Jabbour, Contributing Writer
(...)
Sheehan considered himself an experiment of one. What worked for him, may or may not work for others. He saw racing as the only reason for running. He ran hard in every race, believing that a runner who could walk out of the chute did not try his best.

Philosophically, Sheehan proclaimed that the difference between a jogger and a runner was a race entry form. Therefore, when the fitness craze swept the country in the seventies, he characterized fitness enthusiasts as joggers, and competitive athletes as runners. He went on to claim that health benefits ended where competition began, and that runners raced for a goal higher than fitness.
     
Google Books
The Quotable Runner:
Great moments of wisdom, inspiration, wrongheadedness, and humor
By Mark Will-Weber
Halcottsville, NY: Breakaway Books
2001
Pg. 31:
“The difference between a jogger and a runner is an entry blank.”
—Dr. George Sheehan