Week 3 of the 5 week tune period ... 10 mile people, let's go for 10. 15 mile people , how 'bout 15?
Again, for added benefit, pick *4* miles somewhere in the middle and gun 'em at HM pace. Get used to this: next week we'll have 15-20 minutes at tempo in the middle (that's "Monday" pace). But this week, please focus and hold an honest half marathon pace for 4 miles.