Depends, few years back only doing mileage ran just over 57 for the Army 10-miler. At that time, there was no way I would have been able to run a 4:45 mile. That said, if you're not consistently doing 8 - 12 mile runs, it's going to be difficult to hold a sustained effort for an hour.
In terms of consistency of my runs here's my weekly schedule
T- am 3 pm 5.5 (fartlek)
T-8 (w/ tempo or hills)