I’m in the middle of a marathon cycle and have a half marathon tune up in 2.5 weeks. Today I did 3x2 miles at 6:38 with 3.5 mins jog between the sets. Pace was right on 6:38’s the whole time. Tired by end but not dying. Average HR on faster miles was 175 and last half marathon I averaged 179 for entire race. Reasonable to think I’m in 1:28 (6:42) shape for half? Mileage has been 50-60 per week for last 6 months.
Do a 10k race or tempo the week before your half and that should be a good indicator of your half marathon shape.
I've got 10x800 with 90 sec jogs the week and a half before the race, but I won't be able to squeeze in a 10k race since my A race is a marathon in January. FWIW, I did 16 last weekend with first 8 at 7:59 and second 8 at 6:59. Felt very comfortable the second 8 finishing in under 6:40 pace.
I admittedly don't know much about HM-specific training but 3x2 miles with pretty long rests seems way too short to reveal much about HM fitness. "Tired but not dying" sounds to me like it was pretty difficult so personally I wouldn't be optimistic about holding 99% of that speed for over twice the total distance with no rest.
Hope this helps, not trying to be condescending or anything.
It's possible. 3x2 was my go-to workout during my first HM buildup. 5 weeks out I did nearly the same workout, but with longer rests, and ran 1:25. 10 days out, I ran the workout a bit faster and added an extra mile at 6:00 pace, and it doesn't sound like you're quite there yet. So you might just be in shape to run 1:28. Even if you're training through the race, let the pace come to you, and take the first couple miles easy.
An anecdote from my training log:
4/18/2017 -- 1-5-mi warm-up; 3x2mi w/2-min recoveries @ (6:36,6:39), (6:28,6:31), (6:28/6:25); 1.5-mi cooldown
4/30/2017 -- 2.3-mi warmup; Half Marathon @ 1:28:41 (includes 52-second bathroom break at 7.5 miles); 42℉, 15mph wind; light rain; a few hills.
12-week average mileage 44.1.
Well there you go! You ran a 1:28 flat (sans bathroom break) with a little faster repeats and less time between. Sounds like 1:29 is a better goal for me this time around.