"A revolutionary is where you find him," wrote running's leading writer, Dr. George Sheehan, as he reflected on the revolution-charged 1960s. "He could be the guy next door. Joe Henderson looks like a typical guy next door. Out of Iowa, he has the smile and style of the heartland of America. But he has fallen for that old Socratic saw that the unexamined life is not worth living. The first result was revolt, rebellion and a booklet called Long Slow...