Adolph Gruber was a 12-time Austrian marathon champion and three-time Olympian (1952, ’56. ’60) with a 2:23:30 PR. Running was not a big money sport in those days, so after he retired from serious racing in 1965 Gruber went to work as a tobacconist. After failing at that because he could not hide his dislike of tobacco smoking from his customers, Gruber became a physical trainer.
Gruber started out as a cyclist, but he switched to running due to a serious arm injury sustained on the Russian Front in World War II. Between that and his marathons, he was clearly somewhat of an expert on unnecessary pain, thinking it highly overrated.
In 1964, Adolph wrote this for the Long Distance Log: