How important is it to consider the number of rest days you took in a week when looking at your mileage for that week, and planning the next week? For example if you ran 50 miles in 6 days one week, and the following week you'd run 7 days and plan on running 60... how serious of a jump is that?
Another example I guess would be running 50 miles in 5 days vs. 57 in 6 the following week. A big difference in total miles run, yet you're really just taking one fewer rest day... and we will suppose that 2nd rest day in that week was from an injury concern (that was fixed with that extra rest day).