I'm running the Houston half on Jan 13. I'm planning on doing a 2 x 4 miles @ race pace with mile recovery tomorrow, a week out. Is it a bit too late to run this workout? Would an entire week of easy short runs be enough to recover fully for the race?
Depends on your training mileage and your level (ie are you a sub 1:05 guy or a 1:25 guy?. Generally,I wouldn't do that workout a week out because a) its not going to improve your fitness, b) you can risk tiring yourself out and c) if the workout goes bad and your expected "race pace" is off you'll not be very ready to race mentally.
I used to think that 3 easy days (or even a week of easy) days before a race would let me recover fully from a hard session (such as mile repeats)....however I learned the hard way that you can in fact blow your race day performance by killing yourself in a workout (or series of workouts) as much as 10 days before the race.
2 by 4 miles is quite a bit of volume for a "tune up " workout....I'd consider it a tune-up since your race is next week. I'd recommend doing something like 2-3 by 2 miles at half pace or just a 30-35min "threshold run" at marathon pace working down to half marathon pace. You might want to do something to turn the legs over a little during the week also however....an entire week of easy running might be tapering too much.
something like 10-16 by 200 about 3-4 days out at a pretty conservative pace (ie 3k-5k race pace).