The temptation to run extra miles is always greater once you've committed to a marathon, but not always wiser. Wednesday I felt great even though I had run 15-16 miles on Tuesday. Did I go long again? In my younger days, of course. Today, I was tempted but stuck to the plan- easy 60 minute run in the morning and a short 30 min bike in the afternoon.
Yesterday (Thurs), feeling good, I did a 4 mile tempo in 25 min and change (9.4 mph ave on the GPS). I have not tried a workout like that in recent memory, but now I have a goal to shoot for next time (break 25 min).
As you get older (I am 55), enjoy your easy days.