I enlisted in the Corps in 1967 before being selected for OCS. The annual fitness test was called the Physical Readiness Test and included a 3 mile forced march in boots while carrying your rifle, pack and two canteens. The time limit was 36 minutes if I recall.
When that was eliminated in favor of the current test, a former Commandant said “We’ll look pretty when we’re knocked off a hill in our Nikes.” The current Corps is in fine physical shape, but I like that old test.