At my school, not D1 but bear with me, a lot of the really good ones would be leading the hard workouts and also frequently running really slowly, way behind everyone else on easy days. I mean 8min. pace or so. I used to be a stubborn sort that would keep up with the pack every chance I could, but I got much better when I gave in and just ran whatever pace I felt like on the easy days.
Without recovering, there cannot be improvement. Usually just sleeping overnight is not enough before hammering again.
When your body is really broken down from a hard workout, ask yourself if it would help to go slower. The quicker you recover, the sooner you can get in another good workout.
In the base phase, of course you want to keep the mileage. That's why you shouldn't ever hammer too hard during this period. If you keep it aerobic, you can pretty much recover overnight.