6wks to do a 1h30 half-marathon

Not sure what you might be able to do now, but:

1. If you did 3:25 and 1:35 on 40 mpw and have been running 10-15 mpw, in 6 weeks your chances would be slim if you had gone from 40 years old to 30 years old (!) in the intervening time, but going from 40 to 44 makes your chances less enviable.

2. That 3:25 and 1:35 seems pretty slow compared to decent 18:30/~40 for 5K/10K, so I think the real issue would be to determine how to improve your longer distance training -- but that won't happen in 6 weeks (and I realize the marathon didn't go as planned, but still ...).

I'd love to be able to help out, but if I say how to maximize race performance in 6 weeks after you've been at such low mileage, I fear I'd be steering you into too much injury risk.

Good luck, though.

I suppose it doesn't help much, but I bet you could do a handful of really nice races in 1, 2, and 3 years!

Unless you're already at sub 1h30 fitness (unlikely as you haven't trained much or raced in 3 years), this won't happen in 6 weeks.

Take the time to ramp up the mileage to your previous high and more, then start doing workouts. There is no shortcut, but you should return to previous fitness reasonably fast.

Personally I wouldn't race a 21k so soon but something shorter (10 or 5) to figure out current fitness level and pace workouts accordingly.

You have a chance, if: 1) you ran those times without cheat shoes and now wear them, 2) you weigh the same or less, 3) the course is flat.

However based on your previous PR's, I'd reckon that your long run and thus your aerobic fitness was too low or you ran the 1:35 on a really hilly course, or both. 18:30 is too good for only a 1:35. Age is also not on your side.

Yes. Part of the rationale behind my reply: 1:29:20 on a 19:12.

But on the age caveat: That was older than OP, and I had not gone sub-18:30 for 5K after age 40.

Thank you - honest and really helpful. I'm relying on reclaiming fitness is quicker/easier than building it from scratch...but Your observation about a poor half/marathon time vs 5k/10k times is a good one... this is just a lack of a proper aerobic base (not enough miles). Trouble is, I find if i get to much more than 50mpw, my injury risk jumps, so i could never quite solve that problem and build the aerobic base i felt i needed.

so for this one i feel i'll just have to run slow miles over the next few weeks at c. 70% HRmax, try and get up to 40 or 50mpw, but come race day, i'll have no idea what do target. maybe in 3wks or so there is some sort of exercise i can do to see where my HM time might be? can i infer much from a 5k or 10k race?

5k time was 5000m on a track, to be clear, and the 1h35 was part of a full marathon.

But either way, the aerobic base i needed to go sub 3hr was never really there.

Why did you wait until 6 weeks before a half marathon PR attempt to start training for it?

I did this a few years back (age 45, relatively soon into my adult return to running. Here's what I did.

Weekly mileage: 16 (week 0), 59, 60, 68, 50, 63, 51 (starting taper 10 days out), 33 (including race) - so basically I went straight to 60 mpw, mostly easy miles, and backed off to 50 when I overdid it.

Long easy runs: 19 miles, 20 miles (longer than necessary, I now think)

Workouts (2 per week, including long runs as workouts): 30 minute, 20 minute tempo runs; 10 MP; 6 easy + 5 miles HM pace + 1 mile 10K pace; 3 x 2 miles HM pace; 3 x 2 miles HM + 1 mile 5K pace; some moderate fartlek stuff as well

I ended up running 1:25. You'll probably get injured if you try it, but if you want to give it a try, it's an approach that worked for me.

That's a great effort. I'd get injured for sure, even slowly building up to 60 never mind jumping straight in.

Thanks for the suggestion. An IM triathlete at the office suggested something not-dissimilar, but included intervals, which i generally like doing but i think pretty unnecessary for preparation for a HM race, and probably only add to injury risk. i'm tempted to trust my instinct (and your plan) and skip those, focussing on easy miles, a long run and a tempo workout per week.

Just to follow up on this (apols delay), after 6 weeks of training (on 22-Jun) building up to 35mi/wk, with a 'typical' weekly mixture of 5-6run covering tempo (e.g. 4x1mi@RP) ; intervals (e.g. 6x3'@5kRP, 2' recs), long runs (11-14mi, mix of slow and RP blocks) and recoveries, basically just as much as i thought i could get away with without injuring myself... i ran 1h33'44. So a fair way behind my 1h30 target, but just over a 1' ahead of my PB 5yrs ago, so not a bad result all-in.

And now for my 'excuse': my race strategy was to run at as close to 7'/mi as i could for 12mi, and try to 'kick' in the final mile. Unfortunately as i am type 1 diabetic, i rely on a Libre monitor in my arm to give me live blood glucose readings, and for some reason during the race the bluetooth connection failed, leaving with a stale (high) reading... (i started off the race at 16, which is very high, but i really didn't want to risk injecting insulin just ahead of a race) - so for 10/11mi i believed i was hovering at 16 and therefore didn't take any gels, whereas in reality my BG was of course diving (as you'd expect during such effort). I crossed 10mi at 69'15 (6'56/mi pace), so was on my target strategy and felt pretty good... but very soon after that i felt everything drain away as i realised i my connection was lost and i was hypoglycemic....and my pace dropped off a cliff. At mi11 I swallowed 4 gels in quick succession to try to get my BG up, but i could hardly run and at that point was genuinely worried i might not even finish. I limped over the line (final mi pace was something like 8'30) feeling a bit silly, but relieved at least i broke my PB.

So my lesson learned was to ignore my BG reading and take gels - which was obvious really, and totally stupid not to take any gels throughout the whole race (until mi12).

Thank you very much to all for the advice; I reckon i could hopefully knock on the door of 1h30 in my next race with a bit more training and a better nutrition strategy.

I think that's an amazing result, all things considered! I was 90% sure you'd injure yourself by ramping mileage and effort up too much in too short a time frame, but sounds like you were just a bluetooth error away from the perfect race. Congrats - you'll get the sub-90 on the next one I'm sure