In the 1960s, running for exercise was so unusual that some people were stopped by police in the US.
In 1968, Sen. Strom Thurmond found himself stopped by a police officer in Greenville, South Carolina. His suspicious activity? Jogging.
Back in the 1960s, jogging was something only athletes and boxers really did. Normal people mostly didn't do it — and when they did, it was cause for concern. The New York Times ran an amused trend piece in 1968 on the handful of unusual freaks who chose to run in their free time.
Today joggers are everywhere, and we take them for granted (of course, we usually call them "runners"). But it took surprisingly long for jogging to break into the mainstream.