Like Fisky, until I got one of the black plastic jobs, I had an analog watch with the rotating bezel that you rotated so the zero aligned with the time you started. Most of my routine training runs were over routes whose distances I knew well, from driving them or riding my bike around them.
Intervals were trickier, especially in waning light of autumn. I was young though, and the numbers on my watch and the sweep hand (as well as the others) were faintly luminous. I can remember one set of 8X800m which my partners and I were trying to do in under 2:40. Checking my watch on the run in the dim light after first lap of the opener, I imagined I saw 90 rather than 80, so we picked it up. Apparently I had seen a 70, as we finished in 2:23 or some such. Let's say the remaining seven were...difficult.
Photos of me in '77 Portland Marathon show that telltale skinny black plastic band on my left wrist with 26 splits on athletic tape around it.I remember in '78 Boston comparing the times on my watch with official (and unofficial) mile markers en route.